S. HRG. 350
EARTHQUAKE ]IN MEXICO
SCIENCE, TECIIINOLOGY, AND SPACE
COMIMI[TTEE ON COMMIERCE,
SCIENCE, AND TRANSPORTATION
TINITED STATES SENATE
THE EARTHQUAKE IN MEXICO
OCTOBER 3, 1985
Printed for the use of the
Committee on Commerce, Science, and Transportation
U.S. GOVERNMENT PRINTING OFFICE
54-9690 WASHINGTON : 1986
54-969 0 - ~6 - 1
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COMMITFEE ON COMMERCE, SCIENCE, AND TRANSPORTATION
JOHN C. DANFORTH, Missouri, Chairman
BOB PACKWOOD, Oregon ERNEST F. HOLLINGS, South Carolina
BARRY GOLDWATER, Arizona RUSSELL B. LONG, Louisiana
NANCY LANDON KASSEBAUM, Kansas DANIEL K. INOUYE, Hawaii
LARRY PRESSLER, South Dakota WENDELL H. FORD, Kentucky
SLADE GORTON, Washington DONALD W. RIEGLE, JR., Michigan
TED STEVENS, Alaska J. JAMES EXON, Nebraska
BOB KASTEN, Wisconsin ALBERT GORE, JR., Tennessee
PAUL S. TRIBLE, JR., Virginia JOHN D. ROCKEFELLER IV, West Virginia
W. ALLEN MOORE, Chief Counsel and Staff Director
RALPH B. EVERETF, Minority Chief Counsel and Staff Director
SuECOMMITFEE ON SCIENCE, TECHNOLOGY, AND SPACE
SLADE GORTON, Washington, Chairman
BARRY GOLDWATER, Arizona DONALD W. RIEGLE, JR., Michigan
NANCY LANDON KASSEBAUM, Kansas ALBERT GORE, JR., Tennessee
PAUL S. TRIBLE, JR., Virginia JOHN D. ROCKEFELLER IV, West Virginia
Opening statement by Senator Gorton 1
Opening statement by Senator Gore 2
Opening statement by the Chairman 5
Opening statement by Senator Hollings 5
LIST OF WITNESSES
Bragg, Jeffrey S., Administrator, Federal Insurance Administration, FEMA: and
Jerold M. Haber, manager, Hazards Engineering Department, National
Technical Systems 74
Prepared statement 79
Questions of Senator Gorton and the answers 81
Johnston, Dr. Arch C., director, Tennessee Earthquake Information Center,
Memphis State University: Dr. Robert B. Herrmann, professor of geophysics,
Department of Earth and Atmospheric Sciences: and Linda Noson,
seismologist, geophysics program, University of Washington 58
Prepared statement 60
Sozen, Dr. Mete, professor of civil engineering, University of Illinois: and Paul
J. Flores, director, Southern California Earthquake Preparedness Project 44
Prepared statement 47
Speck, Dr. Samuel, Associate Director for State and Local Programs and
Support, FEMA, accompanied by Gary Johnson, Acting Director, Division of
Earthquakes and Other Natural Hazards: Dr. Dallas Peck, Director, U.S.
Geological Survey, accompanied by Dr. John Filson, Chief, Office of
Earthquake, Volcanos, and Engineering: Dr. Nain P. Suh, Assistant Director
for Engineering, NSF: and Dr. John W. Lyons, Director, National
Engineering Laboratory, NBS, accompanied by Dr. Richard N. Wright,
Director, Center for Building Technology: and Dr. E. V. Leyendecker, Leader,
Earthquake Engineering Group 6
Questions of Senator Gorton and the answers of Dr. Speck 11
Dr. Peck 15
Dr. Suh 23
Dr. Lyons 29
EARTHQUAKE IN MEXICO
THURSDAY, OCTOBER 3, 1985
COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION,
SUBCOMMITTEE ON SCIENCE, TECHNOLOGY, AND SPACE,
The subcommittee met, pursuant to notice, at 10:25 a.m., in room
SR-253, Russell Senate Office Building, Hon. Slade Gorton (chair-
man of the subcommittee) presiding.
Staff members assigned to this hearing: Cassie Phillips, staff
counsel; Chris Ostrom, professional staff member; and Pat Wind-
ham, minority professional staff member.
OPENING STATEMENT BY SENATOR GORTON
Senator GORTON. Since our entire first panel is here, we will
Good morning, and welcome to this hearing of the Science, Tech-
nology, and Space Subcommittee of the Senate Commerce Commit-
Two weeks ago today, one of the largest earthquakes in North
American history shook Mexico City and the surrounding areas.
The epicenter of this earthquake, which measured 8.1 on the Rich-
ter scale, was 250 miles southwest of Mexico City. The following
night a second large earthquake measuring 7.5 on the Richter scale
hit in the same area.
The effect of these massive earthquakes on such a densely popu-
lated area-some 18 million people live in the Mexico City metro-
politan area-has been tragic. News reports indicated that as many
as 10,000 lives may have been lost. It has been estimated that over
7,000 buildings were damaged, and about 450 of those have been
The buildings which failed to withstand the impact of the earth-
quake included federal buildings, schools, and hospitals. Financial
loss from the destruction of the buildings alone has been estimated
to be at least $2 billion. The destabilizing effect of the disaster on
the banking and financial community, and the tourist industry
Mexico's second largest industry, is still taking its toll.
This earthquake has been a truly catastrophic event, causing
untold human tragedy and enormous financial loss. Such an event
could occur, and indeed some time in the future it is quite likely to
occur, somewhere in the United States. Thirty-nine States, in fact,
are exposed to the threat of a major earthquake.
For this reason, it is imperative that we begin immediately to
draw upon the Mexican experience to learn as much as we can
about the effectiveness of our own earthquake preparedness and
This hearing will begin with a panel of representatives of the
Federal agencies which are conducting activities under the Earth-
quake Hazards Reduction Act. The agencies will include the Feder-
al Emergency Management Agency, the U.S. Geological Survey,
the National Science Foundation, and the National Bureau of
Just last March we heard testimony from these same agencies
during a hearing considering the reauthorization of the earthquake
program. Last Monday, I am pleased to say, the President signed
that authorization bill into law.
All four agencies have received preliminary reports from teams
of experts who are in Mexico City surveying the effects of that
earthquake. They will be able to tell us about the Mexican earth-
quake, and response, and about lessons we can learn that either re-
inforce or suggest possible weaknesses in the elements of our own
Following the Federal agency panel, we will hear a firsthand ac-
count of what happened in Mexico from two earthquake experts
who have just returned from Mexico City. Both were sent to
Mexico as part of a National Academy of Sciences team, the mis-
sion of which was to survey the impact of the earthquake before
much of the evidence was destroyed during the cleanup effort.
One is a structural engineer. The other is an expert in prepared-
ness and disaster response. Both are probably exhausted, and we
truly appreciate their willingness to testify.
The third panel represents the point of view of those who work
on earthquake preparedness and mitigation programs at the re-
gional, State, and local levels.
A final panel will discuss the complex issue of earthquake insur-
ance and the effect of a major earthquake on the insurance indus-
try and financial community.
This hearing was called on rather short notice, and I thank all
the witnesses for their enthusiastic cooperation. I should also em-
phasize that these reports from Mexico City are still preliminary.
A great deal of information from Mexico will be collected and ana-
lyzed, and many reports will be forthcoming. This committee will
continue to have great interest in those findings.
At this point I will ask Senator Gore whether he would like to
make an opening statement.
OPENING STATEMENT BY SENATOR GORE
Senator GORE. Yes, Mr. Chairman. Thank you very much.
Two weeks ago today the world witnessed one of the worst natu-
ral disasters of recent years. On September 19, an earthquake reg-
istering 8.1 on the Richter scale struck the western coast of Mexico.
The tremors from that quake and a second quake the following day
spread throughout central Mexico and devastated the Nation's cap-
ital, Mexico City, even though that city lay nearly 200 miles from
the epicenter of the quake.
The damage caused Mexico City by the quake was extensive.
Hundreds of buildings were destroyed. Thousands of people were
injured or left homeless. Officially over 5,000 people died, and the
number could be much, much higher.
The tragedy of Mexico City's earthquake illustrates all too stark-
ly the devastation that can result when a city is prepared to cope
with neither the eventuality of an earthquake nor the tremendous
damage that can be caused by one.
Indeed, the city lay vulnerable to the earthquake that struck it
like a sad, helpless giant. Many of the buildings were structurally
incapable of withstanding an earthquake, and the ground upon
which the city stands actually amplified the shockwaves.
Even worse, once the disaster had occurred, the city proved in-
capable of responding quickly to the disaster. Fortunately, Mexico
has received aid from many of its fellow nations, including the
United States, and bit by bit the city is recovering. There are many
lessons that we in the United States should learn from the earth-
quake that devastated Mexico City.
Foremost among these is that we must do everything within our
ability to assure that no city or area in this country suffers like
Mexico City because of an earthquake. We must take every step to
make certain we are prepared for the eventuality of earthquakes,
and that we are capable of responding swiftly and effectively to
them when they occur.
Earthquakes are not a possibility. They are a certainty, at least
for the millions of people in this country who live near fault lines.
I am especially concerned about earthquake preparedness in Amer-
ica because many of those people live in my home State of Tennes-
see and in the surrounding areas that lie near the New Madrid
As chairman of the House Science and Technology Subcommittee
on Investigations and Oversight over the last several years, I
chaired several hearings on earthquakes in the eastern United
Those hearings led me to conclude that not nearly enough is
known about the dynamics of earthquakes east of the Rocky Moun-
tains, and that more must be done to increase our understanding of
them. But while our knowledge is limited, our past experience with
such quakes provides us ample cause for concern.
The most powerful earthquake ever to strike the continental
United States occurred along the New Madrid fault in 1811. Cen-
tered near New Madrid, Missouri, the Great New Madrid Earth-
quake actually consisted of three separate earthquakes that rocked
the Mississippi Valley on December 16, 1811, on January 23, 1812,
and again on February 7, 1812.
It is estimated that the three quakes measured 8.6, 8.4, and 8.7
respectively on the Richter scale. The great New Madrid earth-
quake was so powerful that it is said to have caused the Mississippi
River to run backwards. The shockwaves it produced rang church-
bells as far away as Boston.
It has obviously been many years since that quake occurred, and
while several earthquakes have occurred over the last 174 years
since that time, they have all been much less severe. Nevertheless,
the threat of a major earthquake hangs disconcertingly over the
residents of the New Madrid region.
It has been estimated that there is a 40 to 60 percent chance that
a quake measuring at least 6 on the Richter scale will strike the
area before the year 2000. The odds of such a quake occurring
before the year 2035 increased to 86 to 97 percent.
The concern about a possible earthquake is especially prevalent
in the city of Memphis, the largest city in Tennessee, and in the
surrounding west Tennessee counties. Fortunately, because of their
foresight and concern, the people of Memphis and west Tennessee
are beginning to take steps to minimize the dangers of an earth-
quake to the area.
Efforts are under way to ensure that buildings are made earth-
quake proof. Public education programs are being conducted now.
The Tennessee Earthquake Information Center located at Memphis
State University is doing a tremendous job of monitoring earth-
quake activity in the region, and keeping the public well informed.
Additionally, a significant step toward earthquake preparedness
in the eastern United States was taken in April of last year, when
the Federal Emergency Management Agency announced the cre-
ation of a Central U.S. Earthquake Consortium.
The Consortium has established an earthquake monitoring
center, and assisted in the development of a 5-year earthquake pre-
We touched upon that plan briefly when Dr. Speck of FEMA tes-
tified before the subcommittee earlier this year, and I am anxious
to hear more about it from him today.
FEMA has also recently completed a major study of the potential
effects of earthquakes on six cities across the United States, and
Memphis was one of the cities examined. So I am anxious to dis-
cuss that report as well.
Despite the many efforts under way in Tennessee and elsewhere
to prepare for an eventual earthquake, more can and must be
done. That is one of the main reasons that we are here today, to
learn how we can avoid the mistakes that led to the tragedy of
Mexico City. We must resolve that a disaster like that which oc-
curred in Mexico City will never happen in this country.
Mr. Chairman, I want to thank you and congratulate you for
holding this hearing so quickly after the events in Mexico City. It
is important that we begin now to consider what took place there
The witnesses who will testify today will assist us invaluably
with our inquiry.
And finally, Mr. Chairman, I want to say how pleased I am that
Dr. Arch Johnston of Memphis will testify here today. Dr. John-
ston is the director of the Tennessee Earthquake Information
Center, and is regarded as one of the foremost experts in this coun-
try on earthquakes.
He testified before my subcommittee in the House, and I have
worked closely with him and his colleagues at Memphis State on
several projects. I look forward to continuing that relationship here
as a member of this subcommittee, and I especially look forward to
the testimony today.
Senator GORTON. Thank you, Senator.
The distinguished chairman of the full committee, Senator Dan-
forth, has a written statement which will be included in the record
at this point, and Senator Hollings has requested that his state-
ment be included in the record of the hearing.
[The statements follow:]
OPENING STATEMENT BY THE CHAIRMAN
Thank you, Senator Gorton, for promptly assembling before the Subcommittee
such an impressive panel of experts. The Committee will benefit from the testimony
of these who have just returned from Mexico. The tragedy that occurred there two
weeks ago serves as a warning to other countries, including the United States, to
take a close look at what can be done to increase preparedness and decrease the
adverse consequences of a catastrophic earthquake.
Of particular interest to me is the preparedness of the central United States. Run-
ning through part of Missouri is the New Madrid Fault. It is along this fault that
the strongest known earthquake in the continental United States occurred-the
1811 quake that is estimated to have hit 8.7 on the Richter scale. Perhaps there is
much that we can learn from the experience in Mexico that could help avert a simi-
lar tragedy in the future.
I would also like to thank the Subcommittee Chairman for inviting Dr. Robert
Herrmann, Professor of Geophysics at St. Louis University. I am sure that his anal-
ysis of the situation in Mexico, especially the disastrous effects of a large earth-
quake amplified over very long distances, will prove useful to the Committee.
OPENING STATEMENT BY SENATOR HOLLINGS
Mr. Chairman, as the death toll continues to mount, there is little doubt that the
recent earthquake in Mexico will go down as one of the most horrific tragedies of
the 20th Century. The massive destruction, the widespread loss of life, and the
homelessness it created would severely strain the human and economic capabilities
of any nation, let alone our financially-troubled neighbors to the south.
In this respect, if there are any positives to note from Mexico's awful experi-
ence-and I would stress that there are very few-then they would surely include
the courage of the Mexican people and the dedication of the rescue workers, both
Mexican and foreign. Perhaps another is that this catastrophe may teach us how to
better prepare for future earthquakes and better respond to them when they occur.
This is the reason for this Subcommittee hearing today.
Mexico City was far from unprepared for a major earthquake. It has modern
building codes and a comprehensive emergency response plan. In many ways, it
seems, those preparations and plans worked. Most buildings in the capital survived,
and emergency teams were deployed quickly
Yet questions remain. To begin with, Mexico City lies 250 miles from the quake's
epicenter. How could such a distant event create such intense destruction? Are
United States cities more vulnerable to distant earthquake than we now believe?
Second, while most buildings survived in Mexico City, many did not, including
several hospitals. Utilities-especially long-distance telephone operations-were se-
verely disrupted. Why did these problems occur? Were building codes inadequate, or
was the problem one of poor enforcement? Given the fact that designing earth-
quake-proof buildings is a new and inexact science, what can the Mexican experi-
ence teach us about which designs do and do not work? Are American designs ade-
Finally, press reports suggest that gaps developed in the rescue and response ef-
forts. The need for heavy equipment and extra medical teams exceeded expecta-
tions. What do these problems suggest about the adequacy of our emergency re-
sponse plans in the United States?
I hope that our witnesses today can shed light on these important issues. I realize
that it will take time to learn the full lessons of the Mexican earthquake, but it is
not too soon to start our examination.
Mr. Chairman, I commend you for holding this hearing and for your leadership in
this important area of earthquake preparedness. Your state, like mine, is threat-
ened by seismic dangers. I am pleased that the Subcommittee continues its efforts to
understand and deal with this threat.
Senator GORTON. We are now prepared to begin with the Federal
panel, starting with Dr. Speck of FEMA, to be followed by Dr. Peck
of the Geological Survey, Dr. Nam Suh of the Science Foundation,
and Dr. Lyons of the National Bureau of Standards, in that order.
STATEMENTS OF DR. SAMUEL SPECK, ASSOCIATE DIRECTOR FOR
STATE AND LOCAL PROGRAMS AND SUPPORT, FEDERAL EMER-
GENCY MANAGEMENT AGENCY, ACCOMPANIED BY GARY
JOHNSON, ACTING DIRECTOR, DIVISION OF EARTHQUAKES
AND OTHER NATURAL HAZARDS; DR. DALLAS PECK, DIREC-
TOR, U.S. GEOLOGICAL SURVEY, ACCOMPANIED BY DR. JOHN
FILSON, CHIEF, OFFICE OF EARTHQUAKE, VOLCANOS, AND EN-
GINEERING; DR. NAM P. SUH, ASSISTANT DIRECTOR FOR ENGI-
NEERING, NATIONAL SCIENCE FOUNDATION; AND DR. JOHN W.
LYONS, DIRECTOR, NATIONAL ENGINEERING LABORATORY,
NATIONAL BUREAU OF STANDARDS, ACCOMPANIED BY DR. RICH-
ARD N. WRIGHT, DIRECTOR, CENTER FOR BUILDING TECHNOLO-
GY; AND DR. E.V. LEYENDECKER, LEADER, EARTHQUAKE
Dr. SPECK. Thank you, Senator Gorton and members of the com-
mittee. We appreciate the opportunity of appearing before this
The Mexican earthquake dramatizes that the earthquake hazard
threatens us with the greatest catastrophic event we face short of
war. Moreover, there is a 50-percent chance that a catastrophic
earthquake of the proportions suffered by Mexico will happen in
Southern California, if not elsewhere in the United States, within
the lifetime of most of the people in this room.
While hopefully we can avoid war, at this point we can at best
only reduce the impact of a catastrophic earthquake.
This morning I would like to focus on two things: First, what are
we doing about this threat; and second, what have we learned and
do we hope to learn from the tragic Mexican disaster.
In 1977, Congress created the National Earthquake Hazards Re-
duction Program, bringing together the earthquake hazard-related
research programs, already well under way, of the three other
agencies represented on this panel, with the activities of FEMA, to
form integrated and comprehensive Federal program.
I have attached a chart to my written statement which depicts
the five elements comprising the program and identifies respective
agency responsibilities. FEMA's mission under the program is es-
sentially threefold: first, to effectively fulfill the lead agency re-
sponsibilities as envisioned by Congress; second, to develop a capa-
bility within State and local governments to prepare for, respond
to, recover from, and mitigate against the effects of an earthquake;
and third, to ensure that the resources of the Federal Government
can be quickly and efficiently mobilized to augment State and local
response and recovery efforts following an earthquake.
I will briefly highlight the most noteworthy activities which
FEMA is undertaking to fulfill this mission. First, with respect to
leadership, FEMA chairs a variety of interagency coordinating
mechanisms at both the senior policy and program manager levels.
These have proven to be effective in dealing with the range of
issues that the national program faces. FEMA also oversees and co-
ordinates the preparation of and submits on behalf of the President
the National Earthquake Hazards Reduction Program annual
report and the 5-year plan.
Second, with regard to building State and local capability, as in
all matters related to public health, safety and welfare, State and
local governments bear the primary responsibility for the protec-
tion of life and property in the event of an earthquake.
They, along with individuals and groups in the private sector,
are the ultimate users of information and projects generated under
the National Earthquake Hazards Reduction Program. FEMA is
providing technical and financial assistance to support earthquake
hazard reduction activities in all of the Nation's high population
These are exemplified by the southern California earthquake
preparedness project and the one already mentioned by Senator
Gore, the central U.S. earthquake preparedness project.
In addition, to assist State and local governments toward en-
hancement of their overall emergency management capabilities,
FEMA developed the Integrated Emergency Management System,
or IEMS, which stresses a functional approach to the management
of emergencies across the full spectrum of emergencies and disas-
ters, while at the same time recognizing the unique elements spe-
cific to particular emergencies.
The functional approach to comprehensive emergency manage-
ment was funded last year by approximately $100 million of civil
defense funds and direct program and training support to State
and local governments. Clearly, the Nation's capability to respond
to a catastrophic earthquake has been enhanced by the Civil De-
Third, concerning Federal mobilization, State and local resources
will be inadequate to respond to the effects of a catastrophic earth-
quake. To meet basic human needs, response of the Federal Gov-
ernment, both from the near geographic area and the entire
Nation will be required. Therefore, in recognition of the increasing
threat of a catastrophic earthquake in California, as well as the
possibility elsewhere, FEMA initiated a response planning effort
that involves the entire Federal Government.
The fourth draft for the resulting national plan was exercised in
Response 85 this past June, and was based upon a simulated cata-
strophic earthquake in southern California. The lessons learned
from Response 85 will be incorporated into a subsequent draft of
the plan, and has just been published within the past several
weeks. Future work will initiate development of Federal regional
plans and include exercises to maintain and update the national
Additionally, FEMA chairs the Earthquake Working Group in
support of the Emergency Mobilization Preparedness Board, which
has been addressing national mobilization preparedness issues asso-
ciated with the consequences of a catastrophic earthquake.
You will find FEMA's program more completely described in at-
tachment 2 to my testimony.
It is important to point out that FEMA has not provided assist-
ance to the Mexican Government to respond to this earthquake dis-
aster, because FEMA does not have any authority to intervene in
Mexico's response effort. Requests for assistance from Mexico are
being handled by the Agency for International Development, and
to date FEMA has not been asked to provide support.
However, in recognition of the earthquake hazard in the common
border areas of San Diego, Tijuana, and Calexico-Mexicali, the
United States and Mexico have developed a joint project to reduce
the effects of earthquakes in these areas. FEMA is directing and
coordinating this Nation's participation in this joint effort. A 5-
year work plan was agreed upon this past year by both govern-
ments, and initial tasks have begun.
However, with the help of FEMA funding appropriated under
the national plan, the National Academy of Sciences Committee on
Natural Disasters has dispatched an initial team of experts to
Mexico to obtain perishable data and provide firsthand observa-
tions of what occurred.
In addition, a joint 5 person NBS/USGS team traveled to Mexico
City to investigate, in a reconnaissance fashion, building damage
and strong motion records. Subsequent teams are expected to
The information obtained from these teams and others will un-
doubtedly provide extremely valuable information upon which to
assess our current activities under the national plan, and if neces-
sary, change our planning for the future.
While it is difficult at this time to supply the subcommittee with
any definitive information based upon actual experience, the wide-
spread media coverage of the event allows me to offer two general
conclusions. First, the Mexican earthquake experience appears to
be consistent with and reinforces planning scenarios developed for
postulated earthquakes in high risk areas of this Nation.
The magnitude and complexity of the post-earthquake response
environment in Mexico in terms of life loss, injury, property
damage, and secondary impacts (such as fire resulting from rup-
tured gas lines), are considerations for which Federal, State, and
local governments are planning in this Nation's high seismic risk
Second, the partial or total collapse of structures is the main
cause of earthquake deaths and injuries. As has been vividly dem-
onstrated, the earthquake in Mexico was no exception.
This fact unequivocally reinforces the need to incorporate seis-
mic resistant design provisions into State and local building codes
throughout the high seismic risk areas of the country. The sooner
this is accomplished, the sooner the earthquake threat within this
Nation will be reduced.
Approximately one-third of FEMA's appropriation under the na-
tional plan is devoted to the development (and dissemination to
design professionals, code groups, and State and local officials) of
seismic resistant design provisions applicable to new buildings, ex-
isting hazardous buildings, and to lifelines.
Unfortunately, this is a difficult and time-consuming task, which
is dependent, among other things, on the results of research and
the support of all sectors of society.
In summary, the seismic activity which so tragically impacted
Mexico City is providing us with a living laboratory of data on
earthquake hazards and the means that can be taken to effectively
FEMA is eagerly awaiting the reports of the onscene assessment
teams which will hopefully provide us with valuable insights on
how the Mexican preparedness and response planning that was in
place at the time of the earthquake actually performed.
For example, was the structured direction and control element of
the Mexican preparedness plan effective? What unanticipated logis-
tical support needs were encountered? Was the organization of the
mass medical care systems adequate? What communication prob-
lems were encountered? What was the impediment to search and
Answers to these and many other similar questions will assist us
in critically evaluating our own preparedness and response plan-
FEMA is also interested in seeking to understand the forces and
structural characteristics which caused building and lifeline fail-
ure. For example, what types of buildings tended to fail, and why?
Did the city's building codes have an impact on reducing losses?
What code enforcement measures had been taken? How does the
geologic understructure relate to the apparent building-to-building
and block-to-block devastation?
It is an unfortunate truth that the tragedy of our sister nation
may well allow us to improve our own efforts in reducing the haz-
ards of earthquakes. However, it will be ironic and a real tragedy
here if we do not learn from that experience.
[The attachments referred to follow:]
A ~ ~
THE FIVE PROGRAM ELEMENTS;
AND RESPONSIBLE AGENCIES
Regional Monitoring and Earthquake
I FEMA ~j
Earthquake Hazards Assessments-National
Postdisaster Mitigation Studies
Precursor Evaluation and Prediction Methodology V//,~7Z~"~
Earthquake Prediction Experiments
Theoretical, Laboratory, and Fault Zone Studies
Development of Design Practices and
Fundamental and Applied Research
Modernization of Existing Research Facilities E:~:E:
National Earthquake Experimental Capability
Earthquake Hazard Mitigation Strategies
Federal Response Planning
State and Local Preparedness Planning
Multi-Hazard Preparedness Planning
Earthquake Education and Information Transfer
Societal Response Research
I Seismological 2
Implications of Plate Tectonics
The Earthquake Pracess NSF
Earthquake Data and Information Services LISGS
ATTACHMENT No. 2.-FEMA RESpONSIBILITI~
1. NEHRP Leadership Role/Interagency Coordination.
2. Seismic Design and Construction Standards
3. State and Local Hazards Reduction Programs
4. Federal Response Planning
5. Mitigation and Multihazard Preparedness Planning
6. Earthquake Education and Information Transfer
[The following information was subsequently received for the
QUESTIONS OF SENATOR GORTON AND THE ANSWERS
Question. What is the Federal Government doing to ensure that Federal facilities
meet seismic-resistant building standards?
Answer. The Interagency Committee on Seismic Safety in Construction (ICSSC),
funded by FEMA and chaired by NBS for FEMA, is taking two major actions in this
regard. First, it has updated a seismic building standard for new buildings that was
first formulated in 1981. The ICSSC member agencies are now balloting this updat-
ed document and a new version, reflecting the results of this consensus process, is
expected to be ready during the current fiscal year. The new version will establish a
minimum level of seismic safety for new Federal buildings, while setting an exam-
ple of seismic hazards mitigation for the private sector to emulate. Second, the
ICSSC has prepared and submitted for balloting to members agencies a draft Execu-
tive Order on the subject of seismic-resistant Federal buildings. A number of policy
questions, including the exact scope of the draft Order, need still to be resolved
before the draft is forwarded to 0MB for its consideration.
Question. Is legislative action by Congress needed to ensure that Federal facilities
will meet seismic-resistant building standards?
Answer. In view of the two major ongoing initiatives described in the previous
answer, FEMA believes that legislative action is not needed at present.
Question. We've heard a lot of discussion about the type of losses that could be
expected if a major earthquake were to strike one of our major metropolitan areas.
Do you have any figures as to what we could expect in terms of insurable losses?
Answer. A study commissioned by the California Department of Insurance exam-
ined the question of probable maximum losses from an earthquake with an 8.25
magnitude. In 1983, the probable maximum loss in San Francisco would be $3.9 bil-
lion; in Los Angeles, $5.4 billion. These figures, which are rising continuously,
assume that 5 to 7 percent of homes have earthquake insurance with a 5 percent
deductible. These figures do not include losses from associated risks: workers com-
pensation, automobile, life and health, fire following an earthquake, and exposure
from landslides or tsunamis.
If the deductible were eliminated which could happen as a result of court rulings,
i.e. concurrent causation, and every homeowner purchased earthquake insurance,
the probable maximum loss would rise dramatically. In San Francisco, the losses
would approach $27 billion; in Los Angeles, $29 billion. Taking into account expo-
sure from associated risks, these figures probably would double: $50 billion in San
Francisco, $60 billion in Los Angeles.
Question. You noted in your testimony that relatively few residential and small
business owners purchase earthquake insurance. Have you been able to determine
the reason for this level of market penetration?
Answer. In 1980, a study was performed for the Federal Insurance Administra-
tion. It showed that homeowners and small business owners assign low priority to
the purchase of earthquake insurance because earthquakes are low frequency
events. This makes the risk seem minimal.
Other reasons stated for low penetration included: Disaster relief programs act as
disincentives for the purchase of earthquake insurance; many residential and small
business owners are unaware of the availability of earthquake insurance; and earth-
quake insurance is not required by lendng institutions to protect mortgages.
Question. I've heard some suggestion that if the Federal government were to get
involved in earthquake insurance that we ought to simply use the National Flood
Insurance Program as our example, and adopt a program similar to what we cur-
rently provide for flood insurance. I notice that you haven't mentioned that in your
testimony. Could you please briefly describe your thoughts on that suggestion?
Answer. I do not envision the solution to the earthquake insurance problem to be
similar to the National Flood Insurance Program (NFIP). Eighty percent of all presi-
dentially declared disasters are flood related. The program has a high frequency and
also has relatively high annual costs. The NFIP has an extensive, costly mapping
program and stringent Federal building requirements as integral components,
Earthquakes, as previously mentioned, are low frequency events. The Federal Gov-
ernment should not impose, and the taxpayers would not accept, the same type of
building standards and costs associated with the NFIP.
To begin addressing this increasing problem, I would envision a partnership be-
tween the private and public sector similar to the NFIP's Write-Your-Own program
initiated two years ago, but one meeting the other criteria I addressed in my testi-
mony. I would be opposed to incorporating extensive risk mapping because the asso-
ciated costs are unjustifiable in light of the relatively low frequency of earthquakes
when compared with other insurance risks. Risk assessment and low reduction ac-
tivities can and should be handled by simple insurance rating formulas.
Question. Do you believe that this is the sort of issue that could be handled at the
state level where insurance is currently regulated, or do you believe that federal
support is required?
Answer. To his credit, California Insurance Commissioner Bruce Bunner is at-
tempting to work with the insurance industry to construct a State solution to the
problem of earthquake insurance. I encourage his efforts, and if he is successful,
that would be the approach to be taken.
Unfortunately, this problem may prove to be more significant than the cyclical
types of cost or availability programs which from time to time come before the Con-
gress. The problems traditionally have been solved either by the private sector or
through State regulation. Earthquake insurance may be one risk that calls for coop-
eration of all parties and innovative solutions.
Senator GORTON. Doctor, thank you very much.
Dr. PECK. Yes. Good morning, Senator. I am Dallas Peck, Direc-
tor of the U.S. Geological Survey, and I welcome the opportunity to
present a preliminary report on the geological aspects of the recent
tragic earthquake in Mexico.
I am submitting a written statement for the record.
Senator GORTON. It will be included in the record.
Dr. PECK. Thank you. And I have comments on a few posters
that we have prepared.
My comments have benefited from the field report of Dr. Thomas
Hanks, one of our scientists who is a member of the team led by
the National Bureau of Standards that was in Mexico City last
Dr. Hanks is in the audience here in the first row. He came here
directly from Mexico City.
I am accompanied by Dr. John Filson, Chief of our Office of
Earthquake, Volcanoes, and Engineering. I think it would work
best, Mr. Chairman, if I just come up here and point out the salient
features on charts that our marvelous staff has prepared.
This first map, a view of central Mexico, illustrates the situation.
Here is the magnitude 8.1 earthquake that occurred at 7:18 a.m. on
September 19. The severe damage occurred as far away as Mexico
City, and the earthquake was felt in El Paso and Houston, TX.
The earthquake filled the Michoacan seismic gap, an area very
low in historic seismicity. There was a 7.3 earthquake in 1981, but
it apparently did not release the seismic strain that had accumulat-
ed in that gap.
Aftershocks occurred along the coast in an area 200 to 300 kilo-
meters long-150 to 200 miles long. There are very few aftershocks
greater than magnitude 5. That was surprising. There was a mag-
nitude 7.5 event on September 20 that itself caused a fair bit of
As I said, the earthquake caused severe damage more than 200
miles away. That is as if an earthquake occurred in St. Louis and
knocked down buildings in Kansas City.
Senator GORTON. Doctor, why was it that the damage was so
heavily concentrated in Mexico City rather than the epicenter?
Dr. PECK. That is because of the local geological situation. Which
is the point of my testimony. We will get to that, particularly in
some of the later posters. Good question.
The crust of the earth is broken into about a dozen plates that
are moving slowly under forces generated by deep forces in the
earth. One of those is the Cocos plate, which is shifting under the
North American plate at about 2'/2 inches a year. This is illustrat-
ed here. This shows the Cocos plate coming out from a spreading
zone and diving under the west coast of Mexico. It moves at about
2½ inches a year.
The earthquake was at a shallow depth of about 20 miles or less
than 20 miles, right along the boundary between the Cocos plate
and the North American plate. The point is that it is moving 2½
inches every year, and that the pressure builds up over a period of
There is enormous strain building up, and the release of that
strain and the slip along the fault causes the earthquake. The seis-
mic waves radiate from the focus, and it was those waves that hit
Mexico City and caused the damage.
Now, under normal situations you wouldn't expect that sort of
damage at a site 200 miles away from the epicenter. However,
there is a thick column of alluvial unconsolidated sediments under
Mexico City, and they amplified the signal, and that was why there
is as much damage.
The next poster illustrates the point, and that is that earthquake
ground motion is amplified by soft sediments both in Mexico City
and in San Francisco. We have done a very detailed study of the
ground amplification of seismic waves in San Francisco using dis-
tant earthquakes and using underground nuclear explosions in
southern Nevada at the test site.
This poster shows, for example, the amplification. This shows the
trace of a seismogram, the shaking from an individual under-
ground nuclear explosion. This is what it looks like on a hard rock.
You can see very, very low amplitude. This shows it on a semicon-
solidated sediment, Tertiary sediments.
This shows what it is like on the bay muds.
Senator GORTON. And that is the red?
Dr. PECK. And that is the red. We have done a very detailed
study measuring amplification at many sites around the Bay and
relating that to geologic mapping of the material. That was pub-
lished just a few years ago in this Studies for Seismic Zonation of
the San Francisco Bay Region.
Senator GORTON. Now, does that indicate, Doctor, that in the city
of San Francisco itself the same degree of earthquake would have a
widely differing impact in various parts of the city?
Dr. PECK. That is right, and during the 1906 earthquake the
damage was far more intense on the bay muds, the saturated bay
muds and artificial fill.
Incidentally, we have done a similar study in the Los Angeles
region, and we have a meeting November 12 and 13 with city plan-
ners, our colleagues in FEMA, other organizations, and the aca-
demic community to lay out this sort of a zonation for the Los An-
geles basin. We have a meeting late in October in Seattle to discuss
this and other aspects of the seismicity in the Puget Sound region.
54-969 0 - 86 - 2
This is a map of downtown Mexico City showing the geology.
Mexico City is a basin like the basins in the Great Basin in Nevada
and Utah. It was formed by faulting about 30 million years ago,
and filled with a thick section, 10,000 to 15,000 feet of sediment.
Then about 3 million years ago there were volcanic eruptions at
the south part that blocked the drainage. The drainage went from
north to south. It blocked the drainage down here so that the
valley around Mexico City filled up with a lake.
In that lake were deposited muds and ash from the erupting vol-
cano, so there is a thickness of about 150 feet of water-saturated
sediment that covered the thick semiconsolidated sediments in that
valley, and it was amplification of the seismic waves, particularly
in that 150 feet of saturated mud, that caused the problem.
The situation is that, in the soft sediment, seismic waves are not
only amplified, as shown here, but the period of the energy shifted.
It shifted to longer periods, so that the period was about 1 or 2 sec-
onds from the seismic waves in Mexico City, and that is just about
the same period as the resonance period of buildings that are 5 to
15 stories high.
So, that caused part of the problem. Another part of the problem
is that in the soft muds of the Mexico City region, the buildings
sink, as they sink in parts of San Francisco, and some of them sank
very quickly as a result of shaking of the ground during the earth-
quake, and that also caused part of the problem.
That concludes my testimony.
[The statement follows:]
STALTI'IENT OF DR. DALLAS L. PECK, DIRECrOR, U.S. GEOLOGICAL SURVEY
The U.S. Geological Survey (USGS) is a major participant in the National
Earthquake Hazards Reduction Program. The goal of the USGS participation in
this program is to mitigate earthquake losses that can occur in many parts of
the United States by providing research, evaluations, and data for earthquake
warnings, hazards assessments, engineering design, and emergency preparedness
decisions. Specific objectives of the USGS program are: (a) to evaluate the
earthquake potential of the seismically active areas of the United States;
(b) to provide assessments of earthquake hazards in developed regions; (o) to
predict damaging earthquakes; (d) to provide data and information on
earthquake occurrences to the public and scientific community; and (e) to
provide data and studies of strong earthquake shaking for use in earthquake-
resistant design and construction. The September 19, 1985, Mexico
earthquake, with all its tragic consequences, provides lessons and experienoe
to help u.s further our work toward all of these objectives. I would like to
discuss our current understanding of the Mexico earthquake and its effects.
Further study pt this event and its consequences will be required to develop
a more ooaplet~and accurate picture.
On Thursday, September 19, 1985, an earthquake of magnitude 8.1 struck
the western coast of Mexico near Plays Azul in the State of Michoacan. The
earthquake caused widespread damage in central Mexico, particularly severe in
Mexico City, and was felt as far north as El Paso and Houston, Texas.
For an earthquake of this size, there were few large aftershocks
lsdiatsly following the sam shock; none above sagnitude 5. Then on Friday
- -~ evffliflg, Sipteaber 20, 1985, a second sajor .arthquake of sagnitude 7.5
occurred in the- region. `The epicenter of this second event was located about
100 ka southeast of the main shock; it is considered an aftershock of' the
larger earthquake. The aftershocks following the 7.5 event have remained
small; however, further damaging earthquakes in this sequence in the
magnitude 6-7 range cannot be ruled out. The length of the sequence is
likely to be measured in months.
Reports from the field indicate that the distribution of aftershocks
covers a region about 300 km long and 150 km wide. Since the zone of
aftershocks is usually taken to represent the dimensions of the fault break
in an earthquake, this event represents a major rupture of the plate boundary
that occurs just off the western coast of Mexico.
These earthquakes occurred in a narrow seismic zone that runs some 2500
km along the western coast of Central America from Panama to central Mexico
west of Puerto Vallarta. This zone of intense seismicity is formed by the
collision of the Cocos Plate to the southwest and the North American Plate to
the northeast. The crust and upper mantle of the Earth are segmented into
about a dozen sections or plates that slowly drift away from zones of crustal
spreading found along mid-ocean ridges. About 90 percent of the Earth's
seismicity is found along plate boundaries, either along mid-ocean spreading
zones or where plates collide.
In the vicinity of the recent Mexico earthquakes the Cocos and North
American plates are converging at a rate of about 6 cm per year. (In human
terms, this is about the rate at which fingernails grow). Along the line of
convergence the Cocos plate dips beneath or is overridden by the North
American plate giving rise to earthquakes along the coast and volcanoes
inland in central Mexico.
The mechanics of colliding plates are complex. The relative motion
between the rocks in the two plates oan be accommodated as contin~aous
aseismio (non-earthquake-generating) slip in the fault zones that have formed
at the plate boundaries. In other cases the faults do not slip continuously,
but accommodate the relative plate motion through elastio deforpation in the
nearby rook. These cases give rise to earthquakes. The ability of the rock
at the plate boundary to absorb the plate motion elastically through strain
aoot~sulation jà~lisited. When this elastic limit is exceeded the rock or
fault breaks ~tantaneously and an earthquake results. In most fault zones
continuous as~saio slip and earthquakes occur. The degree of each depends
upon the details of the fault geometry and its mechanical properties. These
properties also dictate the types of earthquakes that occur in a given zone
of a plate boundary. The elastic strain may be released by numerous smaller
earthquakes with fault breaks measured in tens of kilometers or by infrequent
major events with rupture zones measured in hundreds of kilometers.
Given that plate motion is constant over the long term and that
individual zones of a major plate boundary have a characteristic style or
mechanism of accommodating plate motion, statements about regional earthquake
potential are possible and are now oconly sade. Thea. atatassats are based
on the general oonoepte given above and the past record of eert~uakes in the
region. If a particular zone is overduà for its oh~ictii~i~tiiui~tkjk.;
or an earthquake has never occurred within it, a `seismic gap' is said to
Mexican and United States scientists have studied the characteristics
of the various seisxsic:zones of the western coast of Central America for
several years and have teen able to establish patterns or cycles in some
areas. One study has concluded that prior to 1981 no large earthquake
(greater than magnitude 7) had occurred in this century, and perhaps since
1800, in the zone of the recent earthquake. There is some question concerning
the location of a magnitude 7.9 event in June 1911 that might have occurred
in this zone. Nevertheless, the region has been identified as the
"Michoacan seismic gap" in recent literature. The length of this gap was
about 150 km. Adjacent seismic zones seem to have seismic cycles that give
rise to earthquakes of about magnitude 7.5 every 35 years or so. It was
suggested that either the Michoacan gap was aseismic, the plate motion being
accommodated by continuous slip, or, alternatively, that the recurrence time
of earthquakes ir. this zone was much greater than those in adjacent zones. A
corollary to the latter alternative is that the more infrequent earthquakes
will be larger than those in adjacent zones.
In October 1981, a magnitude 7.3 earthquake occurred in the eastern half
of the Michoacan gap, dispelling the notion that the region is incapable of
generating large earthquakes. Following the 1981 Michoacan event the
aftershocks spread over only about one-third of the gap, leading to the
conclusion that the gap had not been "filled." The questions of whether a
magnitude 7.3 was the characteristic earthquake for the region or whether the
region was capable of producing a larger earthquake, one that would fill the
gap, continue to be debated.
Although detailed analyses of the recent events have just begun, there
is little doubt now that they released the accumulated elastic strain in the
Michoacan zone, filled the gap, and may have broken into adjacent zones. It
now seems important to revise priorities and reexamine the entire region of
seismicity off the western coast of Mexico and to revise earthquake potential
estimates pertaining to it.
The human tragedy caused by the Mexican earthquake has been widely
reported in the press and on television in the United States and will not be
repeated here. The most significant hazard mitigation lessons of the
earthquake are found in studying what happened in Mexico City and why.
Mexico City is notorious for being shaken by earthquakes, many of which
have epicenters 300-500 las away along the plate collision zone discussed
above. For example, in a small booklet entitled Earthouakes j~ ~ we
find this quote: 5Whilo local otfioials were ersiting the entrance into the
City of the leader of the revolution on Juno 7, 1911, there vms a major
earthquake at ~4:26 £11. The local barracks of San Comae were demolished as
well as other buildings and walls in different parts of the city. There vera
39 badly wounded and 119 deaths. Other earthquakes were subsequently felt and
church bells rang by themselves. The earthquake of June 7, 1911, was the
most intense since that of 18145." This describes the earthquake in 1911 that
may have been located in the Michoacan area near the recent earthquakes. The
book covers the period from 1729-1961 during which there were 13 instances of
earthquake damage in Mexico City, an average of about once every 18 years.
The characteristics of earthquake shaking at any location are influenced
by a number of factors including: the magnitude of the earthquake, the
distance of the site from the source of energy release, the geologic
properties of the rock that transmit the seismic waves from the source to the
site, the source mechanism of the earthquake, seismic wave interference or
focussing effects related to broad geologic structures near the site, and
local soil and geologic conditions at the site. Damage resulting from the
ground shaking, of course, depends upon the design and construction
characteristics of buildings at the site. Since Mexico City has a long
history of being particularly senstive to earthquake shaking and was more
heavily damaged than cities and towns closer to the recent earthquake, local
geology and soil conditions must have played an important role in the
distribution of recent damage as they have in the past.
Mexico City lies in a broad basin formed by block faulting of a uplifted
plateau about 30 million years ago. About 3 million years ago volcanism in
the region was renewed and lava flows formed a dam across this valley just
south of Mexico City. This dam resulted in the formation of a large lake
that slowly began to fill with silt, clay, and ash from nearby volcanoes.
Changes in the climate during this period led to oscillations in the level of
the lake. Remmants of ancient beaches indicate that about 7,000 years ago
the level of the lake was about 160 meters above the main level of the
present city. Indian civilizations developed around the lake and, indeed,
the Aztecs built their capital on an island in the lake connected to the
shore by causeways. The Spaniards, after conquering the Aztecs, destroyed
the causeways. They soon learned the causeways played an important role in
flood control for the Azetc city. To solve the flood problem, canals were
built to drain the lake to the north. As the water level dropped, several
small lakes were formed from the single lake and portions of the old lake bed
were exposed around the ancient Aztec cipital. This lake bed has been used
for the expansion of Mexico City. Today, much of th~ City re8ts on lake
deposits made up of silty, volcanic clays and sands with thicknemses of 50
meters or grea~r. These lake deposits overlay other, older sedimentary
sequences with~thioknesses up to 2,000 meters. The lake clays are very
compressible ód have a high-water content. These characteristics, along
with ground water pumping, have led to the sinking of some buildings in
Mexico City and the requirement that large structures be placed on sunken
When unconsolidated material underlies a site, the seismic shaking is
modified from what it would have been on competent rock. The amplitude of the
earthquake ground shaking on unconsolidated material, relative to that on
hard rock, can be increased in some frequency ranges and decreased in others.
The degree of amplification of the ground motion is a function of the seismic
wave velocities, the density and other ssohanioal properties of the material,
its thickness and water content, and irregularities in the rurfeco of the
bedrock. The general trend is for unconsolidated sediments to increase the
amplitude of ground shaking at lower frequencies relative to competent sites.
As the high amplitude ground shaking shifts toward lower frequencies (longer
periods, say .5 - 3 seconds) it shifts toward the resonant frequencies of
higher buildings~ If the ground is shaking at the natural or resonant
frequency of a structure, severe damage and collapse are more likely. Energy
is pumped into the base of the building at the frequency the building will
naturally vibrate because of its design. This causes the ground shaking to
be amplified in the building.
Early reports from Mexico City indicate that of the total of 500-600
collapsed structures, many or them were in the 5-15 story range, with
relatively less damage in lower and taller buildings. This may indicate that
the vibrations in the underlying sediments were in tune with the natural
frequencies of these mid-level buildings. Observation of variations in
damage in identically designed nearby structures indicates variable ground
motion over short distances, or variable construction quality, or both. These
early reports indicate that complete foundation failure may be involved in
about 10 percent of the collapses. -
Although much more research and study of this earthquake need to be
carried out, the causes of the concentration of destruction in Mexico City
are probably due to one or more of the following factors:
o amplification of ground shaking at lower frequencies due
the unconsolidated sediments on which much of the City is built,
o weakened structures due to settlement of foundations, and
o coincidence of the frequency of maximum ground shaking and
It is estimated that over 100 recordings of strong shaking, either of
the ground or in structures, will be obtained from instruments throughout
Mexico. Thie*~1ata will be invaluable in carrying out further research.
The Mexico earthquake was reported to various Federal agencies and news
services by the USGS's National Earthquake Information Center. This was done
by telegram within an hour of the event, following routine procedures.
During the next few days USGS employees at the National Earthquake
Information Center and other locations responded to numerous requests by
Federal and foreign offioiala, th. press, and the public for information on
....... end on urthquaksa in general. Inforaation gathering was haspered
severely by lack of telephone oounioation with Mexico City.
Two USGS scientiats were part of a study team to Mexico City led by the
National Bureau of Standards and supported by the Office of Foreign Disaster
Assistance of the Agency for International Development. The USGS scientists
were to meet with counterparts at the University of Mexico to discuss the
earthquake and its effects. The USGS received no request for assistance from
the Mexican government.
Relation to Current USGS Program
The Mexico City experience reinforces the requirement for the study and
understanding of local geologic conditions on earthquake ground shaking and
the application of this understanding to construction practices and land use.
The USGS has carried out studies of ground shaking amplification in San
Francisco and Los Angeles and is pursuing similar work in the Salt Lake City
and Anchorage areas. Experience in the Mexico City earthquake can be used to
refine and accelerate these studies. It is important, if possible, to pursue
and apply techniques that allow assessment of this problem without expensive
drilling at a particular site or without waiting for the site to be shaken by
The recent event clarifies the tectonic processes off the coast of
Mexico and will provide valuable data for the future assessment of long term
seismic risk from this area. In view of the seismic gap approach to the
assessment of risk, it points to the care that must be taken in assigning
seismic risk to a zone of a seismic region when that zone has no record of
large earthquakes to date.
Finally, this earthquake points to the importance of a multi-faceted
approach to earthquake hazard mitigation. Earthquake prediction, detailed
earthquake hazards assessments, seismic-resistant design, engineering, and
construction practices, and earthquake emergency planning and response all
play an important role in saving lives and reducing property losses. From
the study of the recent Mexico City earthquake we can learn how these various
elements can be better developed and applied in the future in the United
States and elsewhere.
Senator GORTON. Thank you very, very much, Doctor. That was
tremendously enlightening to us.
Dr. Suh is next.
Dr. SUH. Thank you, Mr. Chairman and members of the subcom-
mittee, and thank you for giving the National Science Foundation
the opportunity to provide testimony on the Mexican earthquake to
Mr. Chairman, in preparation of this hearing, we prepared writ-
ten testimony which I would like to submit for the record.
Senator GORTON. It will be included in the record in full.
Dr. SUH. My oral testimony will be brief, covering only the rele-
I would like first to outline some of the activities we have under-
taken at the National Science Foundation in response to the Mexi-
can earthquake. First, we sent a quick response team to Mexico
City through the Earthquake Engineering Research Institute and
the National Academy of Engineering. They have provided us with
some preliminary information.
Second, we have sent several additional individuals under exist-
ing grants to Mexico to collect highly specialized and perishable in-
formation related to the earthquake. Example areas are fire conse-
quences and performance of health facilities and activities.
Third, we have made an offer through the Department of State
to the Government of Mexico to provide engineering support
through our research community.
Fourth, we have established through the Earthquake Engineer-
ing Research Institute and the National Academy of Engineering a
reconnaissance team briefing meeting to be held on October 14 to
decide on the followup actions required to maximize learning from
Fifth, we had in place, through existing cooperative research
projects, a strong motion network near the earthquake epicenter.
The earthquake record data appear to be of excellent quality. We
have also been involved in cooperative activities related to strong
ground motion studies in the Mexico City Basin.
I have a few slides which I would like to show to illustrate some
of the things we have done. In view of the earlier testimony, I will
The first slide shows that Mexico is not far away from the
United States, and so we are neighbors. In view of the earlier testi-
mony, I will not go into details, but as the slide illustrates, the real
issue here is the the severity of the damage 250 miles away from
The next slide shows the earthquake risk region along the Cali-
fornia coast. One of the interesting things is that the nature of the
faults along the western coast of Mexico is quite different from the
nature of the faults in California. The faults and geologic structure
are similar to that near the coastline of the States of Washington
Senator GORTON. I am sorry. Would you repeat that? You were
saying the California situation is different from Mexico, in regard
to the type of fault, but that the fault in Mexico is like that in
Dr. SUH. Yes. The Mexican earthquake occurred along a type of
plate boundary known as a subduction zone, that is a type of inter-
action whereby one giant lithospheric plate thrusts beneath an-
other. That kind of situation exists along the coast of the States of
Washington and Oregon.
Senator GORTON. Senator Gore referred to the New Madrid situa-
tion in the Midwest. Is that a third and different kind of fault?
Dr. SUH. Senator, I am not a specialist on this topic. It is my un-
derstanding that the New Madrid situation is not a plate boundary
geometry but rather an interior plate situation. I can have my spe-
cialists answer further questions on this topic if you wish.
The slide shows that a fault extends all the way along where the
plates meet. Again I emphasize that the geologic structure setting
existing along the coast of the States of Washington, Oregon, and
Alaska is similar to that which exists along the western coast of
The next slide shows a reinforced concrete building. This build-
ing was somewhere between 8 and 14 stories tall. Most of the
buildings that collapsed in Mexico City were of reinforced concrete
construction. It should be noted that these 8- to 14-stories-tall build-
ings had a period of about 2 seconds, and that the earthquake
motion, as we will show later, had a maximum acceleration at a
period of 2 seconds. Therefore,, the buildings, which had a natural
resonant period of 2 seconds, were coupled with the earthquake
motion and hence were the ones which collapsed.
Senator GORE. When you say period, that is the length of time
between the wave peaks?
Dr. SUH. That is right; period is the inverse of frequency. The
next slide shows a steel building. It shows that even steel buildings
can collapse. I understand that most of the buildings that collapsed
were of reinforced concrete construction.
This is another view of the same collapsed steel structure.
Senator GORTON. Excuse me. Would you go back to the previous
slide, back up one?
Now, there you are illustrating, I take it, that the collapsed
building in the foreground was a steel frame building?
Dr. SUH. Yes.
Senator GORTON. There is one building in the background which
looks totally intact. Is that because of the height of this resonance
that you are speaking about? Why would you have that striking a
difference in two adjacent buildings?
Dr. SUH. Senator, your perception of the situation is important.
In fact, both buildings are 21-story-tall steel buildings. One building
collapsed, and the other did not. The question is, Why? We do not
know all the answers. However, this indicates that during an
earthquake different responses can occur over a few hundred feet
This is one of the topics that requires research attention. Why do
those special variations occur and why do two similar steel struc-
tures located next to each other perform differently during an
earthquake? These are research issues, and we do not have all the
Again, this is another view of the same building and it shows the
degree of damage that can occur. The next slide is a collapsed
apartment building of the reinforced concrete construction. I un-
derstand that about 1,000 people died in this building. Two of three
wings of the apartment building collapsed.
The next slide is another view of the same collapsed reinforced
concrete building. The next slide is an overall view of Mexico City
looking west from the U.S. Embassy. You can see there are many,
many buildings still standing in the same city where many build-
ings were destroyed. Apparently this is the case because these
buildings and the soil conditions are quite different in this part of
So, again, it is necessary to really understand the details of the
soil conditions and the interaction between the earthquake and the
resonant conditions of the building. In the Mexico City case, this
complex interaction apparently caused some of the disasters we
have described and have seen here today.
You would expect some of the very poorly built buildings to col-
lapse during the earthquake. The next slide shows what appears to
be poorly constructed masonry buildings, and yet they stood up.
The reason we believe they stood up is because the natural fre-
quency of these masonry buildings is much higher than the pre-
dominant ground motion. Therefore, they were not in resonance
with the ground motion and withstood the ground motion and re-
The next slide shows the effects of the breakage of an aqueduct
leading to Mexico City. Water pressure was low and there was a
shortage of water. The next slide shows a seismic record that was
obtained on firm ground during the earthquake in Mexico City.
The acceleration that was recorded here is only about 4 percent of
acceleration due to gravity.
So, on the firm ground, the acceleration is only about 4 percent,
whereas the next slide shows that on the soft ground, because of
the amplification effect, higher acceleration is recorded. This accel-
eration is about 18 percent of the acceleration due to gravity, or 4
to 5 times as high as that recorded on firm ground.
If the buildings described earlier were located in these soft soil
areas, this is where we would expect the major damage to occur.
The next slide is replotting the earlier response in terms of what
we call a response spectrum. This shows acceleration plotted versus
period, and it indicates that the maximum response occurred at
about 2 seconds There are several smaller peaks, but the maximum
acceleration occurred at about a 2-second period which is the nat-
ural period of the buildings which collapsed.
I understand that in California similar buildings with similar
heights would have a natural period of about 1 to 1.5 seconds be-
cause of different construction techniques. A current National Sci-
ence Foundation sponsored research program involved placement
of instruments along the Mexican coastline. We expect to obtain
rich data which will tell us a great deal about the characteristics of
the ground motion near the epicenter. This will be very valuable
data and information which will influence our Earthquake Hazard
Mitigation Research Program. We do not have all the data yet be-
cause these sites are quite remote.
The next slide shows that even the foundation was uprooted and
pulled out of the ground. This illustrates failure of a foundational
system. The top seven stories of the building also collapsed.
This slide is another view of the tragic damage. This shows the
really human tragedy associated with this kind of earthquake. It
was apparent that they did not have supplement means of rescuing
people in a short period of time. They did not have adequate means
of cutting and destroying the concrete to permit rescuing the
people. I believe this is an area in which we need to do more re-
search in the future.
In the next slide you can see the fingers of a woman trapped
under the collapsed building.
The next slide shows a structure under construction at the Uni-
versity of California at San Diego under the sponsorship of the Na-
tional Science Foundation. This laboratory will be used to study
how masonry buildings and bridges will react to earthquakes. This
is under construction and will be completed some time in June.
We show this to you as an example of an NSF program related
to earthquake hazard mitigation. We are very serious about mitiga-
tion of earthquake hazards.
This is the end of the slides, and I have a few more statements to
As you have seen from the slides, the critical question is why
such poor performance occurred to so many structures in a known
earthquake zone. Part of the answer may be due to old existing
buildings which were constructed without the benefit of current
knowledge and practice. However, this would not explain the be-
havior of newer structures constructed under the current code.
Several features of this earthquake were quite different, and
were vitally important in comparing-the actual building perform-
ance to what had previously been predicted.
First, the absolute intensity of motion developed on the old lake
bed were much greater than had been predicted. Second, the dura-
tion of strong shaking was much longer than is normally the case
with a strong earthquake, which resulted in greater structural
Many lessons can be learned from the Mexico earthquake which
would be of benefit to providing greater earthquake safety in the
United States. The chain of events resulting in many collapsed
structures with trapped persons has shown there is a need for an
improved knowledge base for locating and rescuing people.
This area of research has not received high priority in the past
in comparison with other needs. However, it appears that research
is needed in this area. For example, it may be possible to develop
techniques to selectively disintegrate concrete and other materials
in order to free trapped people.
Some of the problems experienced in the Mexico earthquake are
ones that have been under study in our National Science Founda-
tion research programs. It is important to continue these. This dis-
aster presents us with a major opportunity to learn and prevent a
similar disaster from happening in the United States.
Field studies needed to learn from the Mexican earthquake will
be costly to complete. We will do what we can with our limited re-
sources to obtain data and information to maximize our learning
from this most unfortunate laboratory experiment that nature has
provided to us.
[The statement follows:]
STATEMENT OF DR. NAM P. SUH, ASSISTANT DIRECTOR FOR ENGINEERING, NATIONAL
Mr. Chairman and Members of the Subcommittee, thank you for giving the Na-
tinal Science Foundation the opportunity to provide testimony on the Mexican
earthquake to the Science, Technology and Space Subcommittee of the Senate Com-
mittee on Commerce, Science, and Transportation. This opportunity is especially im-
portant to the National Science Foundation because of our significant participation
in the National Earthquake Hazards Reduction Program and our desire to capture
valuable information and learn as much as possible from this earthquake.
First let me provide a brief overview of the National Science Foundation's earth-
quake engineering and science research program. Our research program is divided
into five categories in two different Directorate as follows:
Siting and geotechnical systems
This research addresses the fundamental engineering issues related to earthquake
ground shaking and describes earhquake interactions on geologic structures includ-
ing surface and subsurface soil and rock systems. The primary research areas are
strong ground motion, stability of geotechnical systems, tsunami systems engineer-
ing and lifeline systems.
The purpose of this research is to develop the capabilities to predict the behavior
of structures during earthquakes, establish practical guidelines and methods for en-
gineering design against earthquake loading, and provide economically feasible
methods to strengthen existing hazardous structures. Some specific research areas
are dynamic non-linear systems, new and reliable desirn methodologies, computer
simulation, knowledge based computer systems, damage assessment methodologies
and lifeline systems.
Architectural and mechanical systems
Research is conducted on architectural and mechanical components and systems
whose failure during an earthquake could result in serious loss of life, damage, eco-
nomic losses and disruption. Examples are architectural and mechanical compo-
nents in buildings such as glass and exterior cladding, elevators, building mechani-
cal systems, power generation and transmission facilities, building contents, commu-
nication systems and masonry structures in which architectural and structural sys-
tems may be integral. Motion mitigation systems such as dampers, active control
systems and base isolation devices are also considered.
Earthquake system integration
This category of research supports research and related activities for the integra-
tion of knowledge-producing and knowledge-using systems. Key areas of research in-
clude earthquake mitigation planning; earthquake preparedness planning; impacts,
recovery and reconstruction; and technology delivery.
ASTRONOMICAL, ATMOSPHERIC, EARTH, AND OCEAN SCIENCES DIRECTORATE
Fundamental earth sciences
This research develops the fundamental understanding of the tectonic conditions
necessary for earthquake occurrences and provides a framework for earthquake pre-
diction and hazard evaluation. Areas of research include plate tectonics, crustal
structure, seismology, crustal deformation, and volcanism and landslides related to
Now let me tell you about a few activities currently supported by the National
Science Foundation-Earthquake Hazard Mitigation (EHM) program related to the
We are supporting through our existing programs quick response teams assem-
bled by the Earthquake Engineering Research Institute (EERI) and the National
Academy of Engineering (NAE) which have gone to the earthquake area to docu-
ment highly perishable engineering information. They will be shortly reporting
back on possible research actions following their reconnaissance work.
We have sent several additional individuals under existing grants to Mexico to
collect highly specialized perishable information related to the earthquake. Example
areas are fire consequences and performance of health facilities and activities.
We have made an offer, through the Department of State, to the government of
Mexico to provide engineering support through our research community.
We have established through EERI and NAE a reconnaissance team briefing
meeting on October 15 to decide on the follow-up actions required to maximize
learning from the earthquake.
We had in place, through existing cooperative research projects, a strong-motion
network near the earthquake epicenter. The earthquake record data appear to be of
excellent quality. We have also been involved in cooperative activities related to
strong-ground motion studies in the Mexico City Basin.
We are supporting the development of a new Global Digital Seismic Network with
real time satellite transmission of wide-band digital seismic data. This new Network
will eventually give us the capability to determine the size, precise location, and
source mechanism of an earthquake within minutes of the event. This information
will be most helpful in timely determination of tsunami potential, expected after-
shock pattern, and damage potential.
Masonry structures are widely used structures and are highly susceptible to
earthquake damage. A coordinated research project is underway to provide the re-
search necessary to develop a rational limit state design methodology for reinforced
masonry construction. This is a part of the U.S.-Japan coordinated program for ma-
sonry building research. Information obtained from the Mexico earthquake will
prove invaluable in calibrating methodologies developed under this program.
A major U.S-Japan cooperative research program of large-scale experimental re-
search on reinforced concrete buildings is nearing completion. The ultimate objec-
tive of this program is to improve design practice through joint research. Significant
impact to the professional practice in seismic design is expected and results have
begun to appear in conference proceedings and special reports. The Mexican earth-
quake could provide a missing link toward understanding of full-scale concrete
building behavior under actual intense earthquake conditions.
A research project has been undertaken related to steel structures in another
U.S.-Japan cooperation effort. This is a large scale experimental effort with the ulti-
mate goal of improving the professional practice in earthquake engineering and the
design of steel structures. The Mexican earthquake will make it possible to calibrate
our analytical and experimental techniques.
Dissemination of research results to improve the knowledge of engineers, archi-
tects, building officials, government officials and researchers is an important part of
a successful Earthquake Hazard Mitigation Program. The Natural Hazards Informa-
tion Center at the University of Colorado and the National Information Service for
Earthquake Engineering with components at the University of California and the
California Institute of Technology are two examples of NSF's dissemination pro-
gram. The Mexican earthquake could provide an excellent opportunity to learn
whether dissemination methods were an important factor in the failure of modern
buildings in Mexico City.
The EHM program is providing significant resources for the upgrading of earth-
quake engineering research laboratories through research equipment grants such as
at the University of California-San Diego and the University of California-Berkeley.
One of the programs we are considering for 1986 is support for an Earthquake
Engineering Research Center. Such a research center would allow indepth, coordi-
nated, focused, and systems research on earthquake engineering to be conducted.
Some of the significant features of this proposed research center would be the dis-
semination of research results to users, more focused research and problem solving,
and the involvement of industry leading to improvement and upgrading of the pro-
fessional practice and increased U.S. competitiveness in the international arena.
A research project aimed at increasing the seismic resistance of existing unrein-
forced masonry buildings has been completed. The significant and well received re-
search results have been used as the basis for strengthening several existing build-
ings in the Los Angeles area and for building code decisions. At this time the results
are also being used for proposing building code modifications in Charleston, South
Carolina. Vital information on the behavior of existing masonry buildings may be
available by studying the Mexican earthquake.
Failures during earthquakes are often attributed to loss of the ability of subsur-
face foundation materials to support a foundation by a process called liquefaction.
Through NSF grants to the Earthquake Engineering Research Committee of the Na-
tional Research Council and the Massachusetts Institute of Technology, knowledge
on liquefaction has been assessed and placed in a useful framework through a work-
shop that was conducted during September, 1985. Two more of these national meet-
ings are planned.
An important part of the NSF earthquake engineering research program is the
support of lifeline systems research. Ths includes such systems as water distribution
systems, communications systems, transportation systems, and power distribution
systems. The appropriate functioning of these lifeline systems is necessary in order
to respond to the effects of earthquakes. The Mexican earthquake could provide val-
uable information vital to calibrating analysis and design methods for such systems.
Although we have only received preliminary reports, I would like to describe
briefly some aspects of the Mexico earthquake of September 19, 1985 of which we
The epicenter of the earthquake was approximately 230 miles from Mexico City
and was located along the tectonic plate boundaries extending along the west cost of
Mexico. This places the epicenter approximately 650 miles south of the U.S-Mexico
border. As is well known, similar conditions are present along portions of the U.S.
West Coast and thus the environment exists for similar major earthquakes in the
The earthquake was along a type of plate boundary known as a subduction zone,
that is, a type of interaction whereby one giant lithospheric plate thrusts beneath
another. A tectonic environment with some important similarities with western
Mexico, i.e., a subduction zone, is found near the northwest coast of the continental
United States along the coasts of Washington and Oregon. By contrast the plate
interaction along the San Andreas system in California is of a different type known
as a transform or strike-slip boundary whereby one lithospheric plate moves side-
ways past another. Another major subduction zone is found along southern Alaska
and extending westward into the Aleutians. In some of these areas the known
earthquake potential is very high and confirmed by the existing seismic record.
Along other areas particularly northwestern United States, the earthquake poten-
tial requires careful investigation.
Initial reports of the Richter magnitude of the earthquake were magnitude 7.8
but this was subsequently upgraded to magnitude 8.1. This underestimate of the size
of the event (and consequently of the potential damage and the likely size of larger
aftershocks) resulted from the limited amount of data quickly available from the
present worldwide seismic network. Data from many of the stations are still not
available and it will be some time before detailed studies of the earthquake source
mechanism and of the pattern of aftershocks can be completed. When the Global
Digital Seismic network is fully deployed, complete and accurate information on
earthquakes anywhere in the world will be available almost immediately.
The magnitude of an earthquake indicates the total amount of energy released by
the earthquake but this only provides a rough indication of how the ground may
actually move at a specific point on the surface. The surface motion is of vital con-
cern to engineers who must design facilities to resist such motions but is of less in-
terest to seismologists and geophysicists. There are vast differences in scales of con-
cern to the two groups-scientists tend to work in scales related to crustal dimen-
sions or to geologic formations while engineers must be concerned with dimension of
hundreds of feet related to the scale of constructed facilities. Because of these differ-
ences of interest and of scale, different types of measurements are needed by the
In order to capture information on the actual level of ground motions and the en-
gineers characteristics of such motions, special strong-motion instruments have been
developed. Two significant sparse networks of such instruments were in place in
Mexico at the time of the earthquake. One was a joint U.S-Mexico effort which
placed instruments along the Mexicon west coast. The U.S. investigator for this
project is Prof. James Brune of the University of California, San Diego. It appears
that several of the instruments may have bracketed the earthquake epicenter and
may produce the most significant near fault strong-motion records ever obtained
from an earthquake. Because of the remote location of the instruments and the
desire to capture aftershock information, I cannot yet show you these records. We
have obtained, however, some preliminary data recorded in Mexico City itself and I
would like to show you some of these records.
Shown first is a recording obtained on firm ground at the Institute of Engineering
at the University of Mexico. Peak accelerations in this record are about 4 percent of
the acceleration due to gravity. Next a recording from the site of the Communica-
tions and Transportation Building located on the old lake bed is shown. On these
records the peak accelerations are about 18 percent G which is about 4 to 5 times
the maximum peaks of the previous record on firm ground. This does not come as a
surprise as it has been known for a long time that significant ground motion ampli-
fication can occur on soft soils during earthquakes. For example a 1964 paper by Dr.
Leonardo Zeevaert in the Bulletin of the Seismological Society of America provided
an analysis of Strong Ground Motions Recorded During Earthquakes of May the
11th and 19th, 1962 in Mexico City. The general conclusions of this paper were that
site amplification effects of 300 to 400 percent are possible at low levels of damping
at the natural frequency of the site.
An indication of the effect of such site amplification and filtering effects of the
propagating earthquake waves can be seen by examining a graph showing the be-
havior of a simple structure, which would look something like a heavy golf ball sit-
ting on top of a thin flexible supporting tee. By using a large digital computer it is
possible to examine the behavior of this simple system when the ground supporting
it undergoes the motions actually recorded by engineering instruments during the
earthquake. The characteristics of this simple structure can be preset for the com-
putation so that the natural vibrational frequencies or time period required to com-
plete a cycle of motion is known. The maximum response of a set of such structures
can be examined for an actual recorded ground motion and different natural fre-
quencies for each simple structure. When the maximum calculated values of re-
sponse for each of the simple structures is plotted against the natural period for
each of the simple structures, a picture of how the earthquake might affect elemen-
tary structures is obtained. When this is done for ground motions recorded on the
soft soil layers in Mexico City, it is found that a very sharp peak in the curve ap-
pears at a period of oscillation of about 2 seconds. Another definite peak occurs at
about a 2.4 second period. In this case the peaks are indications of the resonances in
the soft soil generated by the distant earthquake.
The most serious damage was to reinforced concrete buildings in the range of 8 to
14 stories in height. This is in part due to the fact that with design practices used in
Mexico such buildings would have a first natural period of vibration on the order of
2 seconds which would generate strong coupling action with a natural period of vi-
bration of ground motion. Any building or structures having vibrational characteris-
tics involving a 2 second time period are likely to react most strongly to this earth-
quake. Such a typical situation is generally considered in the design of structures.
Due to slightly different design practices, similar buildings in the U.S. would prob-
ably have slightly lower periods on the order of 1 to 1.5 seconds but this fact in
itself is not an overly significant factor in the behavior of the structures.
In addition to damage to concrete structures there was damage to some steel
structures and to lifeline systems. For example one of the main aqueducts bringing
water to Mexico City failed which has caused a serious water supply problem. On
the other hand the subway system in Mexico City evidently suffered little damage.
This is as we would have predicted because the subway tunnels are small compared
to the characteristic dimensions of the earthquake waves propagating through the
Other serious problems arose in connection with fires which complicated remov-
ing trapped victims from collapsed structures and in the overall organization of
relief efforts. The reports of our reconnaissance teams collecting perishable informa-
tion will no doubt highlight many other problems.
Disturbing questions arise concerning the knowledge-base available for earth-
quake resistant design of structures and whether there is a problem in the level of
training available to building design teams. Many Mexican engineers and architects
were trained in U.S. institutions, are recognized for their research contributions
around the world, and are either in practice in Mexico or are on the faculties of
Mexican academic institutions. Our cooperative U.S-Mexico earthquake engineering
research programs reflect this situation. From this it might be concluded that
modern building designs in Mexico City probably represented current state-of-the-
art practice as would also be applied in the U.S. However, many of the designs ap-
peared to be inadequate. Initial reports indicate that a major problem was that the
high intensities of ground motion and the unusually long duration of shaking could
not have been predicted using our current state of knowledge.
The critical question is why such poor performance occurred to so many struc-
tures in a known earthquake zone. Part of the answer may be due to older existing
buildings which were constructed without benefit of current knowledge and prac-
tices. This would not explain, though, the behavior of newer structures constructed
under the current code. We must look then to the earthquake itself. Several fea-
tures of this earthquake were quite different and were vitally important in compar-
ing the actual building performance to what had previously been predicted. First
the absolute intensity of motions developed on the old lake bed were much greater
than had been predicted. Second the duration of strong shaking was much longer
than is normally the case for strong earthquakes resulting in structures which had
coupled responses driving them through more cycles of damaging deformation than
might have been expected. This results in the structural capability degrading with
Many lessons can be learned from the Mexico earthquake which would be of bene-
fit to providing greater earthquake safety in the U.S.
The accuracy of predicting the actual intensities of ground motion to which struc-
tures may be subjected during an earthquake is still an open area of research. Such
accurate information is vital because without it engineers and architects are faced
with a dilemma regarding what loading conditions they should design for. Too con-
servative a loading requirement will result in buildings which are more expensive
than need be. Too liberal a loading requirement may result in structures which
could collapse or sustain unacceptable levels of damage.
The instrument data from the Mexico earthquake provides an opportunity to im-
prove our methods for predicting actual intensities of ground motion and structural
response taking into account local ground conditions, nature of propagation path,
duration of shaking, distance of propagation and other factors which may affect the
coherence of the surface ground motion. In order to capitalize on those opportunities
additional research should be focused on: Subsurface drilling and sampling, subsur-
face insitu testing cross-hole seismic surveys, seismic reflection surveys, seismic re-
fraction surveys, Ambient measurements on unfailed structures, forced vibration
tests on unfailed structures, computer processing and analysis of strong motion data
recordings, Micro seismic surveys, and computer modeling of existing unfailed struc-
The availability of new supercomputers will make it possible to evaluate these
data in a way which would not have been previously possible.
An evaluation of structures which did not fail may be as important as studying
structures which did fail. It may well be that "simplified" methods of analyses of
dynamic behavior of complex buildings and structural systems are not adequate.
The consequence of such a conclusion would be a need for more rational analysis
techniques, better computer methods and software, better information on material
behavior under severe loads and better methods of analysis in engineering practice.
The drama of collapsed structures has been highlighted in early reports. However,
much information is probably available on the performance of architectural and me-
chanical systems. Such structures may still be standing but their functions are im-
paired by the loss of architectural and mechanical systems. Included in this catego-
ry are lifeline systems such as water supply, sewage disposal, electricity, transporta-
tion and communications.
The chain of events resulting in many collapsed structures with trapped persons
has shown there is a need for an improved knowledge base for locations and rescu-
ing such people. This area of research has not received high priority in the past in
comparison with other needs.
Some of the problems experienced in the Mexico earthquake are ones that have
been under study in our NSF/EHM research program. This disaster presents us
with a major opportunity to greatly increase our knowledge about earthquakes and
their effects and possibly to prevent a similar disaster from happening in the U.S.
We will do what we can to obtain the data and information to maximize our under-
standing from this most unfortunate laboratory experiment that nature has given
Senator GORTON. Thank you, Dr. Suh.
Your written statement will be included in the record.
Dr. LYONS. Thank you, Mr. Chairman.
Good morning, and thank you for the opportunity to appear at
this hearing. With me are Dr. Richard Wright to my far left and
Dr. Edgar Leyendecker immediately adjacent. Dr. Wright, a struc-
tural engineer, director of the NBS Center for Building Technology,
is in charge of NBS's role day by day in the National Earthquake
Hazard Reduction Program.
Dr. Leyendecker, also a structural engineer, is just back from
Mexico City, where he led the NBS/USGS team. These gentlemen
are the experts. You will be particularly interested, I think, in Dr.
Leyendecker's summary report, which will consist of a videotape.
So I will try to be very brief.
First, let me say that the Bureau's role under the National
Earthquake Hazard Reduction Program is to facilitate the improve-
ment of the building regulations in the United States with regard
to seismic resistance.
We do this in a number of ways. Dr. Wright, for example, chairs
the Interagency Committee on Seismic Safety and Construction.
We work with the Building Seismic Safety Council to move along
improvements in practices as they are learned. We are conducting
the design concept study for a national earthquake engineering ex-
perimental facility on behalf of our colleagues in the other agen-
We cochair the United States-Japan Panel on Earthquake and
Wind Effects, and to support all of these activities we conduct a
program of research in the structural aspects of the problem at the
Bureau of Standards.
The NBS/USGS team spent the time from September 24 to Sep-
tember 29 in Mexico City. They provided technical assistance to the
U.S. Embassy. They reviewed the situation with regard to struc-
tures in the city to the best of their ability.
They advised U.S. rescue workers and Mexican Government offi-
cials on some of the technical aspects of the rescue efforts, and as I
indicated, Dr. Leyendecker will show you some of the things that
Furthermore, we have summarized some of that information in a
preliminary way in the written statement.
Let me make a few comments about the status of the U.S. build-
ing regulations. We begin in this system with the three model
The uniform building code in the Western United States is de-
signed to provide enough structural stability for escape of people
even in the strongest earthquakes. In the strongest earthquakes we
would be willing to accept considerable structural damage, but we
are not willing if we can help it to accept loss of life.
Not all communities adopt the model codes. Some write their
own. Some do not have any. Not all communities that adopt a code
adopt the seismic provisions. The provisions that are now in the
code would protect most buildings in a severe earthquake.
I cannot say all buildings, because we do not know everything,
and the gentlemen on the panel have already indicated some of the
surprises we have encountered in this latest tragedy.
Furthermore, the current thinking on seismic resistance is not
entirely yet in the model codes, but is in the process of being intro-
duced. The process of making changes in model codes which have
been adopted by communities and eventually become local ordi-
nances is a deliberate and careful, but time-consuming, process. It
often takes several years to make significant changes in these
A parallel effort in building regulation now is underway for Fed-
eral buildings and for those buildings that receive some kind of
Federal support. That effort is being managed via the interagency
committee that I mentioned, and if you have questions about the
status of that, Dr. Wright can provide some detail.
Now I would like to introduce Dr. Leyendecker, who will summa-
rize on videotape what the group found.
[The statement follows:]
STATEMENT OF DR. JOHN W. LYONS, DIRECTOR, NATIONAL ENGINEERING LABORATORY,
NATIONAL BUREAU OF STANDARDS
Mr. Chairman, thank you for the opportunity to testify on behalf of the National
Bureau of Standards (NBS) on what might be learned from the tragic Mexican
earthquake of September 19, 1985, and the consequent possibilities for improvement
of seismic design and construction practices. I am accompanied by Dr. Richard N.
Wright, Director of the Center for Building Technology, and Dr. Edgar V. Leyen-
decker who led the NBS/U.S. Geological Survey (USGS) team investigating the
damages in Mexico City.
In the National Earthquake Hazards Reduction Program (NEHRP) NBS provides
technical support to the development of seismic design and construction practices
for use in the building codes of State and local governments and in the building
programs of Federal agencies, and conducts requisite research. With your permis-
sion, I offer for the record 1 the description of NBS activities prepared for the Fiscal
1985 report of the NEHRP. In summary:
The Interagency Committee on Seismic Safety in Construction (ICSSC) assists
Federal departments and agencies involved in construction to develop and incorpo-
rate earthquake hazards reduction measures in their programs. With financial sup-
port from the Federal Emergency Management Agency (FEMA) NBS provides the
Secretariat for the ICSSC, Dr. Wright chairs the ICSSC and Dr. Leyendecker chairs
its subcommittee on Standards for Buildings, and NBS co-chairs its subcommittee
on Post Earthquake Response Activities.
The Building Seismic Safety Council (BSSC) is an independent, voluntary body,
established under the auspices of the National Institute of Building Sciences, to en-
hance the public safety by providing a national forum to foster improved seismic
safety provisions for voluntary adoption by the building community in planning, de-
signing, regulating and using buildings. With financial support from FEMA, NBS
since BSSC's inception has provided technical support for the BSSC and technical
secretariat for the Overview Committee of BSSC. BSSC's Recommended Provisions
for the Development of Seismic Regulations for Buildings are now undergoing ballot
by BSSC members which will be completed in November, and BSSC is developing an
implementation plan for encouraging widespread application of the provisions
throughout the U.S.
NBS research has produced new data and improved test methods for predicting
the susceptibility of soils to liquefy when subjected to strong earthquake shaking,
and data and techniques for predicting the earthquake resistance of masonry walls.
A large scale seismic facility has been developed for testing resistance of structures
to seismic loading and is being used to study the resistance of full scale bridge piers
with financial support from the National Science Foundation (NSF), the Federal
Highway Administration, and the California Department of Transportation.
At the request of the President's Office of Science and Technology Policy, with
financial support from FEMA and the NSF, NBS is doing the design study for a
National Earthquake Engineering Experimental Facility. The goal of the facility
would be to provide the data, at approximately full scale, and understanding neces-
sary for rapid improvements in the design and construction of earthquake resistant
The U.S-Japan Panel on Earthquake and Wind Effects brings together 15 U.S.
agencies and their Japanese counterparts for cooperation in research and develop-
ment of earthquake hazards reduction practices. NBS provides the U.S. Chairman
and secretariat for the Panel. Current cooperative work includes large-scale struc-
tural testing, post-earthquake investigations, strong motion instrumentation and
data, and evaluation and repair of existing structures.
Under the auspices of the Agency for International Development's Office of For-
eign Disaster Assistance, NBS and the USGS (USGS) dispatched a team of investiga-
tors to Mexico City from September 24 to 29, 1985. The team provided technical as-
sistance to the staff of the U.S. Embassy and identified possibilities to learn lessions
from successful and unsuccessful structural performance that can assist in the im-
provement of U.S. seismic design and construction practices. Team members are:
Dr. Edgar V. Leyendecker, Structural Engineer, NBS, Leader; Dr. William Stone,
1 The material referred to has been retained in the committee files.
54-969 0 - 86 - 3
Structural Engineer, NBS; Dr. Felix Yokel, Geotechnical Engineer, NBS; Dr.
Thomas Hanks, Seismologist, USGS; Dr. Mehmet Celebi, Engineer, USGS.
The Team advised U.S. rescue workers and Mexican officials on means to more
rapidly remove debris from collapsed buildings to speed the search for survivors,
and worked with Mexican experts to identify fruitful opportunities for indepth stud-
ies of structural performance.
Team representatives also briefed the U.S. Ambassador to Mexico and his staff on
the earthquake. This included cause of the earthquake, possible reasons for such
large ground motions, and possible reasons for the observed structural failures.
The Mexican earthquake is more than an example of the many injuries, and
losses of lives, property, economic activity, and national security caused by earth-
quakes. Out of the tragedy also comes valuable data on full-scale structural per-
formance to better understand earthquake mechanisms and effects in order to
reduce future losses. Although it is too early to reach conclusions on details, we can
say the following:
For this large, distant earthquake, damages were especially severe for taller build-
ings on soft soil deposits. Examples of successful performance as well as severe
damage are available. Indeed, most buildings performed well.
Earthquake intensity apparently varied markedly over relatively short distances
due either to changes in soil deposits or to systematic or random variations in dy-
namic motions. We hope to gain important knowledge on the local variations of
A large variety of buildings were exposed to the earthquake. Performance infor-
mation is available on both conventional and innovative systems of interest for U.S.
practice. Engineers will be able to assess the effects of successive improvements
made in the seismic code for Mexico City in 1942, 1957, 1966 and 1976. The efficacy
of repair techniques can also be ascertained from the performance of buildings re-
paired after being damaged in 1957, 1968 or 1979 earthquakes.
Particular emphasis should be given to recovery and dissemination of strong
motion records relevant to areas of significant structural performance; effective re-
search requires knowledge of ground motions.
Mexican engineers and seismologists are recognized around the world for their ex-
pertise. Since our countries are good neighbors and professional relationships are
excellent, collaborations on investigations are feasible and cost-effective. Since
Mexico has financial difficulties exacerbated by earthquake losses, U.S. support for
participation of Mexican investigators may be needed to take full advantage of the
many opportunities to gain new knowledge.
NBS technical support for the private sector Building Seismic Safety Council
(BSSC) and the Interagency Committee on Seismic Safety in Construction (ICSSC)
provides good background in the status of seismic design and construction practices
in the U.S. I offer for the record the report of the Workshop on Implementation of
Federal Seismic Provisions in the Building Programs of Federal Agencies-March
19, 1984, of the ICSSC which describes U.S. seismic design and construction prac-
tices. In summary:
Building codes of State and local governments are based largely on one of the
three model building codes and/or national standards. However, many building
codes in areas of substantial seismic risk do not adopt seismic design and construc-
tion provisions of a model building code or the national standards. None of the
model codes completely references the latest national standards for seismic loads
The majority of Federal agencies that design and occupy buildings use criteria
similar to those of the Uniform Building Code (the model code with the most rigor-
ous seismic design and construction provisions for normal buildings). Such buildings
are intended to: (1) Resist minor earthquakes without damage. (2) Resist moderate
earthquakes without structural damage, but with some nonstructural damage. (3)
Resist major earthquakes, of the intensity of severity of the strongest experienced in
California, without collapse, but with some structural as well as nonstructual
Critical buildings, such as hospitals, are designed to a greater level of safety.
Ongoing research seeks knowledge to accomplish and strengthen these objectives.
The Mexican earthquake experiences will test current U.S. design and construction
practices in situations where Mexican design and construction is similar to that
which would be called for by the Uniform Building Code or other U.S. seismic
design and construction provisions.
Agencies which lease buildings or support their construction under grant pro-
grams tend to use local building codes. Such buildings would be expected to perform
as well (or poorly) as their private sector counterparts in a locality struck by an
ICSSC has drafted a seismic standard for Federal buildings based substantially on
the Uniform Building Code provisions for seismic resistance but incorporating more
recent national standards for seismic loadings and recommendations under consider-
ation by the BSSC.
The Workshop on Implementation of Federal Seismic Provisions recommended:
1. The Federal Emergency Management Agency should draft an executive order
requiring Federal agencies to adopt common seismic provisions for new buildings.
2. The order should be flexible to allow for the inclusion of the special require-
ments of the various agencies.
3. The order should reference the draft seismic standard of the ICSSC as the
common seismic provision.
The ICSSC is working to effect these recommendations. The ICSSC has drafted
and is balloting a proposed seismic standard for new Federal buildings and a pro-
posed executive order for use of seismic design and construction provisions in Feder-
al and Federally assisted construction.
Dr. LEYENDECKER. The dates of our visit to Mexico City have al-
ready been mentioned. I would like to reemphasize some of the
points that have already been made, and these will come up rather
naturally during the course of the discussion.
First of all, Mexico City was not a city in shambles after the
earthquake. Many, many buildings performed well, in fact came
through quite nicely, but there are some areas of the city that were
very hard hit, and I will show you some examples, and only exam-
ples of these particular areas. As we go through the videotape, I
think the overflight will give you an idea in general how the entire
city came through the earthquake, both low-rise structures and
high-rise structures. Many performed quite nicely.
We have already mentioned the problems of resonance in build-
ings 5 to 15 stories tall, and that certainly accounts for some of the
problems that occurred in the buildings, but most likely not all of
the problems that were encountered.
This is a view of the Continental Hotel, which was on the
Avenue Reforma. It indicates some of the damages that occurred to
that structure in the upper stories.
This is a series of Juarez apartment buildings. This brings up an
example of a question that was raised earlier. Why was this build-
ing badly damaged when surrounding possibly identical but I am
sure rather different in some construction details, why did they not
collapse? That question comes up over and over again.
This is the Mexico General Hospital. The first building was six
stories in height, and it completely collapsed. This was reinforced
concrete. The second building was some eight stories in height.
Once again, it completely collapsed. Reinforced concrete comes up
over and over again as being a structure type that collapsed, but it
is also necessary to point out that much of the construction in
Mexico City was reinforced concrete.
This is the reason it was so difficult to get communications out of
Mexico City immediately after the earthquake. This is the commu-
nications building, and as you can see, it underwent rather severe
damage. From the ground you can get a little better idea of the
damages to that structure. We saw upper stories collapsed, and
sometimes intermediate stories collapsed.
If you look in the yellow boxed in area on the screen, what ap-
pears to be one story is actually two stories, but one of the stories
has had all of the columns severed so that the upper several stories
have actually impacted down upon the building. It raises questions
of why all of the columns in that particular level collapsed-was it
quality of construction or dynamic response of the structure, for ex-
We will be moving in just a moment to the opposite side of that
building to give you once again a feeling of the difficulties for this
structure, which really should be considered an essential kind of fa-
cility as far as communication goes with the outside world. Note
that this structure was undergoing some demolition, removal of
documents, removal of computer equipment, and so forth.
We have seen this picture somewhat earlier, if you recall, the
steel building on the ground in the foreground and the two struc-
tures in the background that are still standing. They are not in
quite as good a shape as they might have appeared at first glance,
and I will show you that in just a second. We are always interested
in steel structures, because their performance in earthquakes is
generally quite good, when they fail we need to learn why.
I call your attention now to the circled building that was imme-
diately behind the one in the foreground that collapsed. If you look
at it, you can see it has got a definite tilt and twist to it. It is actu-
ally in quite severe condition, even though it may have looked oth-
erwise in earlier views.
This is Juarez Hospital, a 12-story reinforced concrete building.
This was in the week after the earthquake. We still have 12 stories
of slabs on the ground. There were reported to be somewhere be-
tween 800 and 1,000 people in this structure. Something like 50 or
60 survivors have been recovered.
Rescue techniques here were primarily tunneling into the debris,
in between floor slabs, a very slow process.
This illustrates another possible reason for some of the* severe
damages within the city. Frequently there were adjacent buildings,
one perhaps eight, nine stories tall, adjacent to a four-story build-
ing, where the taller building would be collapsed down to the level
of the shorter one.
If you look closely at the structure, which was adjacent to the
one that collapsed, look in the upper three stories. You will observe
the column bases. They are kicked way in. These two structures
were undergoing what we would term pounding or hammering.
They were literally beating each other to death. The one on the
right won, and it met the design criteria of not collapsing, but the
one on the left certainly did not. In this case additional building
separation would certainly have enhanced the performance of that
We observed many columns sticking straight up, almost like a
forest of trees. This particular slab construction failed many times
by this punch-through kind of failure, and I think there are some
reasons for observing this kind of construction and studying it, be-
cause it is widely used in Mexico City.
There are a lot of lessons that can be learned here, I believe.
Some of them have already been mentioned, and if our Mexican
colleagues and research workers there are as cooperative after the
earthquake, which I am sure they will be, as they were in the first
few days following the earthquake in terms of sharing data on ac-
celerations, building damages, and so on, I think there is a wealth
of data that we can learn from, in spite of the tragedy and human
loss of life and injury to property.
Senator GORTON. Does that complete your testimony?
Dr. LYONS. That completes our testimony.
Senator GORTON. Dr. Peck, let us now consider the various kinds
of tectonic settings in the United States, those which are similar to
Mexico and those which are dissimilar to what we saw in Mexico
City. Would you explain these different tectonic settings, including
that in southern California, the Puget Sound, the Midwest, and
other areas? Then would you answer the question, does it make
any difference once an earthquake comes whether or not these
faults were dissimilar from one another?
Dr. PECK. I will tackle the first one. I think I am going to draw
on Dr. Filson to help me on the second one.
As I explained, the situation in Mexico is an underthrusting of
the Cocos plate under the North American plate. The situation is
different in California, because what we have there instead of that
underthrusting a lateral slip along the San Andreas and related
faults. When we get to Oregon State and Washington State and
Alaska, we have an analogous situation, and that is, the Juan de
Fuca plate is underthrusting the North American plate along the
coast of Oregon and Washington. As a result, there are active vol-
canoes along the Cascades. That is a typical situation.
The rate of convergence of the two plates is about half what it is
in Mexico, and there has been a fair bit of discussion about wheth-
er that movement is taken up aseismically just by the two plates
moving across each other without earthquakes or whether it is
building up toward a major earthquake. That is still a matter of
Now, the situation in Alaska and the Aleutians is again very
similar to Mexico, and the earthquake that occurred on Good
Friday in Alaska in 1964 was a similar earthquake.
Senator GORTON. To that of Mexico City?
Dr. PECK. Yes, with underthrusting of the Pacific plate under the
American plate in Alaska. My understanding of the situation in
the midcontinent in Missouri and western Tennessee is that it is a
third, different situation. That is an ancient rift zone geologically.
The area is similar to Mexico City in that there are water-satu-
rated sediments deposited by the Mississippi River, particularly the
flood plain of the Mississippi River; but the tectonic situation is dif-
At that stage I think I have reached the limit of my understand-
ing, and let us let Dr. Filson--
Senator GORTON. Before we go to him, have we now exhausted
both the locations and the types of tectonic situations in the United
Dr. PECK. No, indeed. There are, of course, many earthquakes in
the Great Basin. Those are due to steep faults and the mountains
getting higher and valleys getting lower. That is another kind of
earthquake. There are historic earthquakes in Charleston and else-
where along the eastern seaboard.
I am not sure we know exactly what the tectonic setting is, but it
is certainly different than that in Mexico or along the San Andreas
fault in California. So there are a number of different tectonics.
Dr. FILS0N. My name is John Filson, from the Geological Survey.
The plate geometry can make a difference in the types of accelera-
tion and ground motion that are experienced in an earthquake.
The propagation of the earthquake rupture can tend to focus
energy-cause large displacements along the direction of propaga-
If a plate is underthrusting a continental margin, the whole rup-
ture surface can radiate energy to sites in the continental block.
These effects can be, in my opinion, as large as the local site effect,
but in general I would imagine that the local site effects would be
greater than the effects due to plate geometries and rupture propa-
Senator GORTON. Now, I am not sure. It may be USGS to which
this question should be directed, but if other witnesses wish to
answer it, I would be happy to have them answer it as well.
Where are we today with respect to our ability to predict earth-
quakes within a timeframe that will allow us to do something
about it? Is this impacted by the type of tectonic situation with
which we are dealing? Is it easier in one place than another?
Dr. PECK. Let me take a crack at that and perhaps then turn to
Dr.. Filson to amplify.
At this stage we, and by we I mean the whole world earthquake
community, have very limited ability to predict the time, place,
and magnitude of earthquakes. We have made a lot of progress on
predicting the recurrence interval of earthquakes and hence the re-
currence in a broad time sense of an earthquake and the earth-
quake magnitude and place.
So, for example, this earthquake was anticipated in a general
way because there was a seismic gap. One can calculate the plate
movements that have occurred since the last earthquake, and
hence the buildup of strain. So in a general way we can predict,
but as far as predicting the exact time, we do not have that ability
now. We are still determining whether indeed it is feasible to do
Now, some earthquakes have been predicted in the past, and pre-
dicted accurately. The Chinese predicted the occurrence of a major
earthquake a few years ago and evacuated the city. The earth-
quake occurred. The city fell down-and the people were not hurt.
So, it can be done. A lot depends on the nature of the tectonic
setting and the fault and our knowledge of the historic occurrence
of earthquakes and the occurrence of premonitory phenomenon
We have an intensive study going on at Parkfield, CA, where
there have been recurring earthquakes of a magnitude about 6
every 22 years for the last 100 years. It comes up again in 1987 or
1988, and we are doing intensive study with our colleagues at the
universities trying to see whether we can see premonitory phe-
Senator GORTON. Senator Gore.
Senator GORE. Thank you very much, Mr. Chairman.
Dr. Peck, can you rule out further aftershocks for Mexico City?
Dr. PECK. I think there is a general tailing off of aftershocks. It
goes on for some time. We have been surprised at how few large
magnitude aftershocks there have been. But again, Dr. Filson will
be more knowledgeable.
Dr. FILs0N. No, sir, we cannot rule out further aftershocks in the
sequence that might affect Mexico City.
Senator GORE. Has the probability of further aftershocks de-
clined with the number of days passing since the initial event?
Dr. FILs0N. Yes, sir. That is a general trend. The farther in time
you get away from the main shock, the less probable are large
Senator GORE. Are they still in a dangerous period?
Dr. FILSON. I would say that aftershocks from the sequence will
be detected over a period of months perhaps a year.
Senator GORE. Now, you talk about particular seismic zones as
being overdue for an earthquake because of the past historical
record and the building up of stresses and so forth. What areas in
the United States are overdue for an earthquake?
Dr. PECK. I mentioned Parkfield, where it is going to be due in
the next very few years. We have determined that the recurrence
interval in southern California, for example, is about 150 years. It
has been 130 years since the last earthquake.
In the southern California region, the last earthquake was in
1857. It is one of those seismic gaps. There are several areas in
Alaska. There is one, if you will pardon the expression, in the
armpit of Alaska, the Yagataga Gap in southern, eastern Alaska,
where seismologists have--
Senator GORE. You are lucky Senator Stevens is not here.
Dr. PECK. It is also a seismic gap there, too. Those are two that
come to mind.
Senator GORE. And the others? What about in the eastern United
Dr. FILs0N. There are regions in the eastern United States that
have experienced earthquakes in the past, such as Charleston, SC,
and others, but we do not have enough evidence. We do not have a
long enough historic record of the seismic history in these regions
to establish reliably recurrence rates.
Senator GORE. Now, it is true, is it not, that the largest earth-
quake ever to take place in the continental United States was the
New Madrid, and if you take those three quakes from December of
1811, through February of 1812, those three quakes together pro-
duced more or released more earthquake energy than all of the
other quakes in known history in the continental United States
Dr. FILs0N. Yes. It is probably the most energetic region over his-
Senator GORE. Now, you talked about the soil conditions in
Mexico City, and you drew a comparison between the soil there
and the soil lying underneath the area around New Madrid. What
are the similarities? Is that just the siltation from the old flood
Dr. PECK. It is saturated fine grade sediments.
Senator GORE. Because of those soil conditions underneath
Mexico City, we saw the propagation of damage far distant from
the epicenter of the quake. Is it not true that generally speaking
earthquakes in the western United States are unlikely to propa-
gate over such distances because of the geology in the West?
Dr. PECK. That is right. The seismic energy does not propagate as
far in the West as it does in the East.
Senator GORE. But in the eastern United States generally speak-
ing a large quake is likely to cause damage over a much larger
area. Is that correct?
Dr. PECK. That is true.
Senator GORE. All right.
Now, Dr. Speck, you recently completed a study of the potential
effects of major earthquakes on six cities in the United States. I am
particularly interested in the results in one of those cities. Could
you briefly summarize the conclusions that FEMA reached about
Dr. SPECK. I am going to ask Gary Johnson, who is Acting Direc-
tor of our Division of Earthquakes and Other Natural Hazards to
respond to that.
Briefly, Senator, that report is in printing, and does focus specifi-
cally on the damages in different areas of those cities.
Senator GORTON. What are the other five cities?
Mr. JOHNSON. Senator, the other five cities are Paducah, KY;
Little Rock, AR; Evansville, IN; Carbondale, IL, and I am missing
one in my mind right now.
Senator GORTON. Go ahead.
Mr. JOHNSON. Our basic--
Senator GORE. What was the fifth one?
Mr. JOHNSON. Poplar Bluff. An additional study right now is
being done in St. Louis, and we have also received a draft report
looking into the effects of the earthquake on tall buildings in the
distant cities of Chicago, Kansas City, Dallas, and Atlanta. We are
currently evaluating that.
Senator GORE. Tell us what your findings were with respect to
Memphis. Give us a preview of this report that is at the printers.
Mr. JOHNSON. What we found in Memphis is a very astronomical
dollar loss in terms of money. That is primarily related to the un-
reinforced masonry construction in the city of Memphis. I think we
are talking in the neighborhood, Senator, of about $33 billion
worth of loss in that particular area.
Senator GORE. $33 million?
Mr. JOHNSON. $33 billion.
Senator GORE. $33 billion with a
Mr. JOHNSON. That is correct: From a recurrence of the 8.6
earthquake that occurred back in 1811. The amount of loss of life
in the area escapes me at this point. It is significant. It is clearly
the greater than in the other five cities.
Senator GORE. I believe it was in the area of 5,000 to 6,000.
Mr. JOHNSON. Yes, that is the correct parameter, certainly, and
the major problem in that area, particularly during the day, is
with the unreinforced construction of school buildings and children
in the schools at the time.
This is certainly something that we need to address in the area,
and it brings up a point not only unique to Memphis but every-
where else: The problem that existing hazardous construction poses
to us, not only in Memphis, but throughout the country, and the
need to develop processes, code provisions, and so forth to be able
to abate the existing hazardous buildings, particularly schools and
other critical facilities.
Senator GORE. Well, the lesson we ought to learn from these as-
tounding figures is not that we should be frightened of the fact
that an earthquake is probably inevitable at some point in the
future. The lesson we should learn is to begin making preparations
now to strengthen these buildings, to have codes that require
future construction to take place in a safe manner. We also need
public education. Indeed, many of these efforts have now begun in
Memphis. But if I understand the testimony of this expert panel,
the evidence that you have compiled is very troubling, because the
damage would be tremendous, and we must step up our efforts to
prepare against the eventuality of an earthquake in the New
Mr. Chairman, my time is expired, I know.
Senator GORE. Senator Ford.
Senator FORD. Thank you, Mr. Chairman.
This is not one of my subcommittees, but it gets awfully close to
Senator GORTON. Paducah was one of them.
Senator FORD. Well, Evansville, IN, is 29 miles from my home
Dr. Peck, we talk about the New Madrid and you indicate that it
would be much worse than other areas, and has been. Something
that occurred on the Mississippi River and rang church bells in
Boston was a pretty good tremor. We have some estimates that
rank the probability of a new quake from 40 to 60 percent in a few
years, and 85 to 95 percent a little bit further.
How close, with certainty in your own mind, could you say that
there would be another quake in the New Madrid fault?
Dr. PECK. Well, for that I will turn to Dr. Filson.
Dr. FILSON. It is very difficult, Senator, to estimate an exact
time. I think we would have to stick with the probability state-
ments that have been repeated or that have been expressed here
earlier, that a magnitude 6 event has a probability on the order of
40 or 60 percent in the next 15 years.
Senator FORD. Now, when we talk about New Madrid then and
we talk about Evansville, IN, as the crow flies a distance of maybe
100 miles, would the effect at 6 be felt in the general area around
Dr. FIL50N. The earthquake, in my opinion, would be felt in the
area. I would also estimate that the damage would not be severe at
Evansville from an earthquake in New Madrid at the magnitude 6
level. There may be some damage, though.
Senator FORD. What about 7.6 or 8?
Dr. FILSON. In that case, certainly there would be, I would esti-
mate, severe damage in that area.
Senator FORD. Let me talk to Dr. Speck just a minute then. In
making the study of these communities, what kind of emergency
preparedness situation do you find in Evansville and Paducah and
the smaller cities, small in comparison to Memphis? I would say
Paducah is around 50,000, Evansville is somewhere around 100,000,
Henderson is right across the river. The last quake I think diverted
the Ohio River and Evansville is Indiana instead of Kentucky, but
they are just right there on top of each other.
Dr. SPECK. Senator, first of all under the integrated emergency
management approach, all communities pretty much are working
to develop the capability to do those kinds of basic functions you
have to do in the face of any kind of disaster, being able to give
direction, control, warning, being able to shelter people or being
able to evacuate people, and medically care for people and the like,
and that is where we are putting a good deal of our resources into
developing that capability, and as part of that, what communities
are doing, we started in 1984 and went to full field implementation
throughout the country in fiscal year 1985 with the multiyear de-
velopment program in which each community does their annual
hazard analysis, vulnerability assessment, looks at the hazards in
their particular area.
On the basis of that, then they look at what their current capa-
bility is, do their operations planning on that, and then look at the
difference between that, the delta between that and where they
need to go, and that goes into their plan and also is reflected in the
That is overall generic capability.
Now, you have to look at the specific earthquake hazard, which
has certain kinds of things in terms of preparedness and mitigation
that are unique, and what we have been doing is working with the
communities that Senator Gore mentioned, the Central U.S. Earth-
quake Project States under the consortium of some seven States, to
do a number of things. One that they are working on right now is
public awareness, getting the public really keyed up in your area
about the need for this kind of planning.
A second they are in the process of doing is doing an inventory of
critical resources because they realize that Paducah is not probably
going to be able to go it on its own. It is going to have to have help
from other areas, and one of the things you know from the earlier
New Madrid earthquake, and we know from that fault situation, is
that it could be in different areas of the fault area, and the studies
reflect that, so that they are looking at ways in which they can
support each other through an inventory of critical resources, these
kinds of things.
They are also looking at interstate mutual compacts that will
allow the communities in one State to support the communities in
I could go on but boil it down to say that through the consorti-
um, the States and the localities within those States are looking at
the earthquake threat from a perspective of what they can do to
help out each other. We are working with them through a variety
of mechanisms such as the vulnerability studies in those six cities
plus now St. Louis and the cities further away, to help them devel-
op the data base.
Senator FORD. In Mexico, one of the biggest problems I found,
and apparently it was said here that others felt the same way, was
Is there any way that you are working on communications needs,
as an integral part of the total program? The biggest thing we had
going for us was ham operators out of this community to Mexico.
I know when I was Governor we had emergency preparedness
plan, and that it was all worked out, and we had certain places to
go and people who would do certain things. Even in flood, we would
have them out on the riverbank to check it every so often to-tie a
string around a bush, if nothing else, to see how fast the water was
But the communications of that information, and the communi-
cations out of the damaged areas seems to be critical.
Now, are you looking into the communications arena as it relates
to our ability-I am talking about Paducah, Evansville, Memphis,
and other communities-to be able to respond to what we need?
Are you looking at what the problems are so that we might be able
to respond in this respect?
Dr. SPECK. First of all, that is being looked at under CUSEPP,
and second, that is part of our overall emergency preparedness
planning in every community and in each State.
Senator FORD. Did we learn something from the Mexico problem
as it relates to communications?
Dr. SPECK. Pardon?
Senator FORD. Did we learn something from their communica-
Dr. SPECK. Yes, I am certain that we will be looking at that very
carefully to see if assumptions as to what we anticipate would be
available and what we anticipate would have to be augmented in
our national response plan that we tested in California were realis-
tic, or whether the Mexico experience tells us that in some ways it
was not realistic.
Senator FORD. One quick question, Mr. Chairman, and then I will
stop, and I do thank you.
Dr. Lyons, I understand from reading and studying about the
Mexico City problem that those buildings on what we call "floating
concrete" sustained the quake much better than others based on
traditional foundations and the mud they were sitting on.
Is that true?
Dr. LYONS. Let me, if I may refer that to Dr. Wright, Senator.
Dr. WRIGHT. Our observations of the performance of the build-
ings in Mexico have not reached the point of being able to compare
the effects of various foundation types, deep piles or mat founda-
tions, one with the other.
Senator FORD. All right.
Dr. Speck, could I have a copy of your report as it relates to Pa-
ducah, KY, Evansville, and so forth?
Dr. SPECK. Yes, sir.
Senator FORD. And one other thing I would admonish you. About
every 6 months you ought to try to scare people.
We had a lot of write-up about all this, and people are really
moving, but it is gone now. Every once in a while you ought to
have someone go down and shoot off a flare.
Dr. SPECK. Mr. Chairman and Senator, if I might briefly respond,
one of the things that I think has been positive in the Central U.S.
Earthquake Project is the increased degree of public awareness in
a relatively short period of time, and that is critical for getting the
public to be willing to support public officials' allocation of re-
sources to do these kinds of things. They have had some very good
success in that regard.
Senator GORTON. We are going to have to go on to another panel
soon, as fascinating as you have been. Dr. Speck, you have talked
around this question in your answers to Senator Ford, but could
you give us the present status of our National Catastrophic Earth-
quake Response Plan on the part of FEMA, and tell us the extent
to which you think that what we are learning in Mexico City is
going to require any changes in that plan.
Mr. SPECK. Mr. Chairman, I will be calling on Joe Winkle, our
Assistant Associate Director for Disaster Preparedness to back me
up on this. He was out and played a major role, in fact, the major
role in the testing of the plan in California this summer. That plan
has gone through its fourth draft now, and it was table-top tested
here in Washington this past spring and field tested in California.
We just got the results of that, and there are essentially nine major
findings of areas in which we need to really follow up and do some
Joe, I will let you address those.
Mr. WINKLE. All right.
Mr. Chairman, some of the things we found as a result of our ex-
ercise wherein we had 24 different agencies involved with about
400 people playing, were one, we want to take another look at our
management structure that we have put together to deal with an
emergency of this magnitude. Of course, the scenario would call for
a major disaster declaration within hours, and there is a mecha-
nism that we traditionally use. There is an appointment of a Feder-
al coordinating officer to coordinate the overall Federal response.
We did find some cumbersomeness with the traditional way that
we have dealt, and so we are readdressing that.
Also, with the group that would be at the Washington level,
which is our coordination group of the policymakers of the various
Federal agencies, we also want to readdress that. We would like to
look and see if we could not streamline that particular body.
And our plan is designed around emergency support functional
areas, and as a result of our experience in our exercise, we feel
that we need to readdress these emergency support functional
areas; possibly look at some consolidation as well as maybe some
additional functional areas that we had not particularly anticipat-
ed, such as that connected with financial issues and the fact that
banks probably would not be able to do business due to the fact of
power outages and the electronic means by which banking is done
One other matter that came up was the business of the Federal
Government liability, and we would like to address that front-end
before we ever have to address it after an earthquake like this
The matter of public affairs; undoubtedly we want to look at how
we can best deal with an overall, joint information network be-
cause of the interest that would be created worldwide.
And lastly, we want to look again at our logistical requirements
to accommodate the mass Federal response that would be generat-
Senator GORTON. Thank you.
Senator GORE. Yes, very briefly, Mr. Chairman.
Dr. Speck, I did not get the name of your assistant there.
Could you identify yourself?
Mr. JoHNsoN. Gary Johnson.
Senator GORE. Oh, that is right. I am sorry. Of course.
Could you supply a copy of the study to which you referred?
Mr. JOHNSON. No problem, sir.
Senator GORE. Fine.
I was really astounded by the number you used, and I have been
sitting here reflecting on that, and I want you to elaborate just
briefly on what exactly that includes.
The question in the study was what would happen to Memphis if
a 7.6 on the Richter scale earthquake struck.
Mr. JOHNSON. As well as an 8.6 earthquake, Senator, the larger
earthquake; and the figure I referred to related to the property
damage loss relating to the larger earthquake, the 8.6 earthquake.
Senator GORE. And that would be just in Memphis?
Mr. JOHNSON. In Memphis, that is correct, sir.
Senator GORE. That would be a quake of the size which did occur
in the New Madrid area during 1811, 1812?
Mr. JOHNSON. Yes.
Senator GORE. What would be the comparable figure for 7.6?
Mr. JOHNSON. Senator, I do not have that figure in my head at
Senator GORE. But for the larger quake, $33 billion in property
damage in Memphis?
Mr. JOHNSON. It is the controlling factor. I believe the total over-
all loss in the area came out to about $50 billion. So Memphis is
clearly the significant area in our studies right now, sir.
Senator GORE. Just astounding
Now, Dr. Speck, what additional efforts should be made to pre-
pare for the eventuality that a large earthquake could take place
Dr. SPECK. Mr. Chairman, Senator Gore, one of the things that
we are focusing on with other agencies such as NBS and the Build-
ing Seismic Safety Council is the whole area of mitigation in terms
of new buildings, in terms of retrofitting old buildings, and in
terms of lifelines, and we are making some significant progress; but
there is a great deal more to be done in this area.
We are just getting the results of work that has been done under
a contract with the Building Seismic Safety Council in which they
have balloted some 58 member organizations in respect to a re-
source document for model codes, developed the information that
has to go into that, and we are in the process of moving to get that
disseminated throughout the country.
The second area is the area of lifelines, and we recently signed a
contract with the Building Seismic Safety Council to prepare a
plan of action in respect to them. The ABE Joint Venture recently
completed a similar plan dealing with existing buildings. A large
number of groups have to be involved if you are going to get these
plans extensively implemented, and we would hope to have the life-
lines plan completed within 18 months.
In addition to that, we are currently balloting the-and you can
maybe speak to that more, Dick-we are currently having a ballot-
ing procedure of the Federal agencies in respect to an executive
order dealing with mitigation standards, building standards, as it
were, for Federal buildings, and the question there is going to be
not only what are we going to recommend for Federal buildings,
but what are we going to recommend beyond that for leased build-
ings or for buildings that Federal money is involved with in some
Senator GORE. Yes.
Dr. SPECK. So those would be some of the major initiatives that
are actively under way in this area which is a critical area.
Senator GORE. Well, I look forward to following your efforts very,
I am glad that some work has already begun in Memphis, and I
am glad the public awareness has been increasing as a result of the
fine efforts that you and others have made. But clearly, in view of
the results of this study soon to be released, 5,000 lives and $33 bil-
lion worth of property damage, we must devote even more atten-
tion and even more effort to making certain that everything possi-
ble is done to mitigate the consequences of such a quake and to
deal with it should it occur.
So I want to thank you for your testimony.
Thank you, Mr. Chairman.
Senator GORTON. Senator Ford?
Senator FORD. I do not think I have any questions.
One thing that we talk about when discussing ways of saving
lives is, what is the time span of warning when an earthquake
begins? Is there any way to determine that, Dr. Speck? I know they
are all different, and some are surprises and some you can make
some kind of judgment, but is there any warning time that you
might be able to give?
Dr. SPECK. I think I will turn to the Geological Survey on that. I
know that if you listen to some other countries, they tell you if you
know how to watch animals closely enough, the animals will tell
you when one is coming.
Dr. PECK. As I mentioned, Senator--
Senator FORD. Well, we go by the moss on the trees.
Dr. PECK. As I mentioned, Senator, there have been some suc-
cessful predictions, a few successful predictions of earthquakes
based on a variety of phenomena, including the rate of swelling of
the ground, the occurrence of flurries of small earthquakes, lateral
shifting of the ground, and it is in looking into that sort of phenom-
ena that we are doing very intensively in the Parkfield area of
But by and large, at this stage, for almost all earthquakes, we
cannot predict an event. The earthquake waves themselves take
some time to travel from one area to another. So for a distant
earthquake, there could be a warning of a minute or so, but beyond
that, no, Senator.
Mr. SPECK. Mr. Chairman, I might add that for that minute or
so, it is not very significant when you are planning to evacuate and
those kinds of things. You obviously do not have anything to plan
against. Even a minute or so can be critical, however, when it
comes to perhaps triggering valve closings on major pipelines and
those kinds of things to prevent or at least reduce explosions. So
even that much warning can be very critical in some areas.
Senator GORE. Would the Senator yield?
Just briefly, you mentioned the animal experiments in other
countries, and the tendency has been to kind of laugh at that here
in the United States, but I am told the Chinese do take that quite
seriously and believe it has real utility.
We still do not understand acupuncture, and yet it works, and
they pioneered that. Should we maybe re-examine our hidebound
attitude about that and investigate whether there might be some-
thing to that?
Dr. PECK. Well, Senator, we are not that hidebound, and we have
actually looked into it in some detail, looked into all the examples
we could gain from our Chinese colleagues and what is in the liter-
ature. We have done some experiments ourselves, supported experi-
ments on both behavior of monkeys and apes and that sort of
thing, and cockroaches, even cockroaches. And by and large, we
have not come up with anything.
After an earthquake, people remember all sorts of funny things:
The dog howled, or chickens ran around in the yard.
It may work better in China because the people are so close to
the animals and watch their behavior, and they enlist the help of
millions of Chinese as part of a network, looking for premonitory
phenomena. That itself may be a factor. But we have not come up
with anything, although I will ask Dr. Filson to speak to the
Dr. FIL50N. We feel that there may be something here like, as
you mentioned, acupuncture or folk medicine legend. There is usu-
ally a truth of a physical phenomenon behind it; we just have not
been able to identify it, nor have the Chinese or any other foreign
colleagues that work in this area. For several years, we ran a hot-
line in California and advertised an 800 number where people
could call and record or put on record unusual animal behavior,
and then we would try to correlate that behavior with the subse-
quent minor earthquakes in the Bay area. We could come up with
no positive correlation.
We have looked at it. We are not very active in that area right
now, but we continue to watch the progress and the experiments of
Senator GORE. That sounds like a mighty responsible approach. I
Senator GORTON. Thank you all very much. We appreciate it.
The second panel, Dr. Sozen and Mr. Flores.
Dr. Sozen, we have just received your written statement. The
entire statement will be included in the record. Because of what
you have obviously seen about time constraints, to the extent that
you can summarize it, we would appreciate it.
STATEMENTS OF DR. METE SOZEN, PROFESSOR OF CIVIL ENGI-
NEERING, UNIVERSITY OF ILLINOIS; AND PAUL J. FLORES, DI-
RECTOR, SOUTHERN CALIFORNIA EARTHQUAKE PREPARED-
Dr. SOZEN. Thank you very much.
I arrived in Mexico City on September 21, 2 days after the quake,
at the request of Mr. Chung from the National Academy of Sci-
ences, and a few days later other members of the Joint Team of the
Earthquake Engineering Research Institute and the Academy of
Sciences and National Science Foundation, and so forth, joined me,
and we stayed there until last Saturday which I believe was the
I have my statements written to be included in the minutes. I
think the facts have been very well described by the people who
preceded me. If I may, I would like to render a few opinions.
Senator GORTON. Please.
Dr. SOZEN. From the viewpoint of structural engineering, of
course, the most significant event in Mexico City was the peculiar
nature of the ground motion. There were various things which
were surprising. One was that the day I hit the deck, barely 48
hours after the earthquake, the records of the ground motion had
been digitized and publicized and were available to all interested
parties, which I think was the first time that I have ever seen it
happen immediately after an earthquake. For comparison, I would
like to mention that we are still to receive the similar records
which were obtained in the Chilean earthquake which was in
April. So the Mexicans are very well organized from that view-
The other thing that was significant was the steady state nature
of the ground motion in that in one particular location in town, as
I think it has been described before, the ground moved a total of
approximately 18 inches back and forth at a very slow pace, once
every 2 seconds. At another spot, only about 5 kilometers away
from it-and I am still talking about the center of the town, the
lake bed, the ground did the same motion in about 3½ seconds.
This is very slow motion, not unanticipated, but it is still uncanny.
Now, another significant feature of this motion was that it went
on for about 20 almost steady state repetitions, increasing its influ-
ence on buildings.
If you will allow me, let me show you a very naive model to ex-
plain what is going on at least from the viewpoint of structural en-
gineering. We have talked about periods of buildings.
Senator GORTON. Yes; please explain.
Dr. SOZEN. Exactly. For example, when I push this little steel
mass back and forth, it goes back at a certain rate, and in that case
I would say it takes about half a second for it to complete one
cycle. It is an analog for the period of a building. Even the building
we are in would have a period, very low. It would do essentially the
same thing, unfortunately.
Now, a high-rise building would have a longer period than a low
rise building. Now for the ground motion that would occur most
likely in hard ground in San Francisco, the ground would go back
and forth-and I know it is an oversimplification-but at a speed
such as four times per second. It would be a very strong motion
which would tend to excite the low rise buildings, the ones with the
In Mexico, the motion was rather slow, and instead of exciting
the low rise buildings, it excited the high rise buildings, and it did
not only excite them, but it kept going on and on until their dis-
placements were very large, so that if there was ever a problem
with the structure or with its stability, it came up.
If I may switch over to a few slides, please, this is a rather hasti-
ly digitized version of one of the motions that was reported in
town, and what I would like to draw your attention to is the dis-
tance between the crossings of the curve on the horizontal axis, or
what we call the zero crossing rate, which kept steady for a very
long time. If we try to interpret this in terms of high and low rise
buildings, what I have there really is a sequential calculation of
buildings which would be low rise and buildings which would be
Senator GORTON. The lowest at the upper left?
Dr. SOZEN. The upper left would be a very low building. The one
that you see on the lower left would represent a building of, let us
say, about 16 or 18 stories. And then on the upper right hand side
again we go higher and higher.
What it attempts to say, and I concede that the slide is rather
mediocre, is that this earthquake selected the buildings in the mid-
rise section, from about 6 or 7 stories to about 17 stories, to excite.
Actually, what happened is that if you think of the vertical axis
as a measure of the damage potential of the earthquake and the
horizontal axis as an indication of where a particular building
would be in relation to its period, for example, if you start out
with, say, a 10-story building having an initial period of 1 second, it
would be mildly excited by the earthquake, and then as it was ex-
cited, it would crack or it would yield, and its stiffness would de-
crease, its period would increase, and as its period increased, then
the demand of the earthquake on the building would be higher,
and then we would have the tragedy.
Now, what is I think important is that Mexican engineers knew
this. What I show you there as a solid line is the design response
spectrum for the soft parts of the city. What is shown there as a
broken line is the response spectrum or earthquake effect that was
actually measured. The two, of course, have been normalized, but
there is no question I think in the minds of the members of the
technical community that Mexican engineers anticipated this type
of motion, and indeed, it was no different from what they obtained.
But I believe what they did not anticipate, and here I am specu-
lating because I have not talked to every one of them, is demon-
strated in this slide which compares a measure of the response to
the earthquake. Now, the curve that you see there with a broken
line is the response to one of our classic earthquakes, El Centro,
1940. It is an earthquake in Imperial County, CA. The solid line is
the response to the Mexico City ground motion, and I think you
will find that up to about 1½ seconds, the broken line is above the
solid line, which indicates that our type of earthquake, or I should
not say our type of earthquake, the earthquake that you would
have on hard ground would really demand a higher energy from
the structure, but once you go to the right, you find that the Mexi-
can motion peaks way beyond one's expectations.
Now, hindsight sets in very quickly in our business. Once some-
thing has happened, then it is very easy to predict it. I think I will
confess to you now as a member of the structural engineering com-
munity that I would have found this comparison very hard to be-
lieve before it happened. The amount of energy that this earth-
quake pumped into their high rise construction was I think at the
extreme edges of the credible region, and I think that is probably
the main lesson I have learned from this earthquake, that I find it
easier to believe the extremes of credible events now than I did
before, and because of it, to me-and I do not live too far away
from St. Louis-the vulnerability of St. Louis and of Memphis is
much less unreal now than they used to be before September 19.
Let me show you a few more slides about the situation. Of
course, I was very much interested in their hospitals because I
work on the Structural Safety Board of the Veterans' Administra-
tion. They had three hospital systems in the city of Mexico. They
were all stopped because of events like this, and of course, it is up
to us now to find out whether the vigorous program that the Veter-
ans' Administration carried out to make sure that all their hospi-
tals were safe and that we would not repeat the tragedy of 1971
again, is really founded on firm ground and that our methods
would be able to, if I may say, retropredict this failure.
Now, about their codes, Mexico City has an excellent, rather so-
phisticated code. This is one of their 13-story apartment buildings.
This was one of three units. This one contains 90 apartments. The
other two did, also. The other two failed.
But you will see that this one was ready to fail. This is one of the
interior columns of the building. And what I see in that particular
case is that the movement of the building was very slow. This is an
apartment inside that building in which things have not been dis-
turbed, have hardly been disturbed. But because of the tremen-
dously high forces created by the earthquake, the system came
* I think their codes were quite competent.
But how well they were enforced I do not know. All I can tell
you is that I looked at-and I know the exact number-57 residen-
tial buildings very carefully that were still standing up. Some had
architectural damage, some had minor structural damage, but in
no case did I see a building that I would dismiss as being substand-
ard construction or having substandard materials.
My immediate reaction to all this is that there is a tremendous
amount of information in terms of data to be acquired from this.
The Mexicans do not know and we certainly do not know how their
foundations behaved. As it was indicated, we have a 21-story struc-
tural steel building, which is supposed to be the indomitable
system of earthquake engineering, on its side. It is essential to
know why it came down.
As you would very well know, looking is not seeing. We have to
do a lot of work in order to be able to appreciate what happened,
and of course, we do not have to do anything at all, but the sooner
we do it, I think the better it will be for our public safety.
I think I will stop here.
[The statement follows:]
STATEMENT OF METE A. SOZEN, PROFESSOR OF CIVIL ENGINEERING, UNIVERSITY OF
ILLINOIS, URBANA-CHAMPAIGN, IL
SEPTEMBER 1985 MEXICO EARTHQUAKE AND ITS IMPLICATIONS FOR RESEARCH RELATED TO
The main Shock of the 19 September 1985 Mexico Earthquake occurred at
13:17:47.6 GMT (7:17:47.6 a.m. local time in Mexico City) and was rated to have a
Richter magnitude of 8.1 (Ms).
The epicentral region has been located near a small town, Lazaro Cardenas, on
the Pacific coast of Mexico in the State of Guerrero. The distance from the epicenter
to Mexico City was estimated to be approximately 400 km. Using aftershock data,
Dr. James Brune of the University of California at San Diego estimated the rupture
to extend approximately 200 km, with Larzaro Cardenas near the middle of the rup-
ture zone. As well as progressing northwest and southeast from Larzaro Cardenas
on the surface, the rupture penetrated obliquely under the landmass of Mexico. An
earthquake related tidal wave (Tsunami) with a height of less than 2 m was ob-
served on the beaches around Lazaro Cardenas.
Strong motion measurements
The Guerrero accelerograph array, which was in the process of being installed as
a joint project of UNAM (National Autonomous University of Mexico) and UCSD
(University of California in San Diego) already had 20 of the intended 30 stations in
place. A total of 18 of these stations produced strong motion records. Measured peak
accelerations in the epicentral region were approximately 0.15 g and the duration of
shaking with accelerations not less than 0.lg exceeded 10 sec.
The institute of Engineering of UNAM maintains a network of approximately a
dozen stations to measure strong ground motion in Mexico City. All of these stations
are reported to have produced data. Jorge Prince of UNAM made reduced data
available to interested professionals one day after the main event. In general, the
strong motion measurements in the metropolitan area indicate first that the inten-
sity of the earthquake in those parts of the city away from the old lake bed was
very small. However, within the central portion of Mexico City, which is founded on
a dried lake bed, the motion was measured to be 0.2 g or approximately five times
as large as in the outlying districts of the city. Another important characteristic of
the ground motion, reproduced in Fig. 1 for one of the accelerograph sites, is its
steady pace. At the site, the ground moved a total distance of approximately 16 in.
completing each cycle in 2 sec. The steady nature of the ground motion exacerbated
its influence on moderate rise construction.
Figure 2 provides a preliminary measure of the intensity of the motion obtained
at SCT, Mexico City. The velocity response spectrum for that motion is compared
with the response spectrum for a well known U.S. strong motion record, El Centro
1940 N. While the spectral velocity for El Centro 1940 exceeds that of SCT 1985 up
to approximately 1.5 sec, at higher periods the motion at SCT has a considerably
higher velocity response.
Figure 3 provides a crude and relative measure of the story displacement of build-
ings with different periods. It may be assumed for a preliminary assessment that
the fundamental period for a given type of building varies with height. Ratio of the
calculated linear single-degree-of-freedom displacement to the period than may be
used as damage indicator. From Fig. 3 it may be concluded that low-rise buildings
(with low periods) would not be excited by the motion measured at SCT while build-
ing with effective periods around 2 sec. (moderate-rise buildings) would be suscepti-
ble. The same conclusion may be made from Fig. 4 which shows the maxima for Fig.
3 plotted against period.
The idealized theoretical trends shown Figs. 3 and 4 were confirmed by observa-
tions of the behavior of actual buildings. In connection with the evaluation of the
safety of buildings in which U.S. Embassy and Consulate officials lived, I investigat-
ed the state of 57 residential buildings in Mexico City. The group up to five stories,
which represents buildings with low periods, had hardly any damage. The group
from 7 to approximately 17 stories included buildings with very heavy architectural
damage, some with light structural damage, and some with foundation problems. In
general, it can be said that moderate-rise buildings were more vulnerable to the
type of strong ground motion experienced in the center of Mexico City than low rise
As it has been widely reported, structural damage to buildings within the lake
bed region was severe. As many as 1,000 structures may have been very severely
damaged or destroyed. In general, this group included buildings ranging in height
from 5-21 stories. Casualties may have approached 10,000.
When I was in Mexcio City, there were many rumors circulating that much of the
damage was due to poor quality materials or substandard construction. I can say
that in my seven-day survey of the damaged and undamaged areas, I did not come
across any moderate or high-rise building, standing or destroyed, that I would dis-
miss as a building with blatantly substandard material or design. Systematic inspec-
tion and tests may reveal such cases in the future, but it is unlikely that more than
a very small fraction of the buildings constructed in the last two decades will be
found to be substandard.
There were some threads of common attributes that Ed Johnson (Atkinson, John-
son, and Spurner of San Diego) and I could observe in the buildings that were de-
stroyed or severely damaged. One of the general problems was the relatively high
flexibility of the buildings caused by the slender proportions of the girders, span
lengths, and (sometimes) column size. The fact that in many structures there were
progressive reductions in column size with height from base gave me the impression
that the designers, presumably staying within the requirements of the Building
Code, were doing their best to economize.
In a few cases, I noticed that the amount of transverse reinforcement used in
their columns was less than what would be required by building standards used in
the United States for earthquake regions.
Another apparently frequent source of collapse was the fact that the first story of
the building was more flexible than the upper stories because of the necessity of
accommodating a garage or stores in the first story.
A recurrent cause of damage in the upper stories of buildings was the construc-
tion of buildings of different heights next to each other with a seismic joint or space
in between the two buildings that appeared not to be adequate for the nature of the
earthquake that was observed. As implied above, the low rise and/or colonial type
construction was not necessarily due to its strength but due to the fact that the
ground motion did not excite low rise structures.
Critical damage due to foundation movements still needs to be evaluated. It is not
to much of an exaggeration to claim that virtually no building in the lake region of
Mexico City is currently standing exactly as it did before the earthquake. There
were several instances of buildings leaning out of plumb from 10 to 15 deg. with the
There was an inventory of buildings that survived the 1957 earthquake with some
damage. Some of these had serious damages during the 1985 event.
Ixtapa, a town near Lazaro Cardenas, is reported to contain several modern build-
ings severely damaged. Structural damage is also reported in the States of Jalisco
Schools and hospitals
In our survey of the city, we observed problems with three school buildings. One
had a total collapse and the other two had partial collapses. For the two with rela-
tively heavy reinforced concrete construction, it appeared again that architectural
requirements had made them flexible so as to put them into the vulnerable range
of periods in relation to the earthquake motion. One of the school buildings, near
the Tepito district of Mexico City, had very slender walls which had clearly over-
I have been told that Mexico City had three main hospital systems: The Juarez
Hospital, the General Hospital, and the IMSS or Social Security Hospital. During
the first week after the earthquake, none of the systems was in full operation.
There was a very serious failure of a 13 story building in the Juarez Hospital. The
General Hospital had suffered two serious failures, collapse of the seven story Ob-
stetrics building and the 14 story Intern dormitory. The Social Security System had
also serious partial collapses in their Medical Center and in the Children's Hospital.
According to my information the patients who had survived found adequate space
elsewhere in the city.
According to the informtion compiled by Luis Escalante (Los Angeles Department
of Water and Power), the National Power Generation and Transmission System did
not suffer significant damage. Distributional lines were damaged in various areas by
collapsed buildings but power loss occurred only in the immediate vicinity of severe-
iy damaged buildings: Estimates effects to the distribution system within Mexico
City were as follows:
Damaged transformers: 113 out of 26,000.
Poles affected: 50 out of 350,000 primary feeder lines.
Lines damaged: 6 km (3.7 miles) out of 10,500 km (6,520 miles).
Secondary distribution lines damaged: 10 km (6.2 miles) out of 15,750 km that is
Consumer connections out of service: approximately 15,000 out of three million
two hundred thousand.
According to Luis Escalante's information, damage to water systems occurred
mostly in the distribution pipelines in the eastern and southeastern regions of
Mexico City. It has been reported that an adequate conveying water from the south
had been damaged.
Insufficient water flow and loss of water pressure affected three to five million
citizens out of an approximate total of eighteen million citizens of Mexico City. The
normal use of water per capita in Mexico City is 30-80 gallons per day. Immediately
after the quake only 3-4 gallons per day per capita was available. By 25 September
1985, most private water cisterns were empty and many people were relying on
tank truck deliveries to communities or purchases by container from itinerant ven-
Propane gas sustems did not suffer significant damage. Collapsed buildings caused
some gas leakage. The only reported major fire due to gas leakage was at the St.
Regis Hotel. Gas from ruptured pipelines ignited and caused a major explosion.
Luis Escalante found that Telefonos de Mexico, the National Telephone Company,
suffered major damage to its long distant telephone transmission equipment and
heavy loss of life among its personnel when the top three stories of this five-story
office building collapsed. All service to outside of Mexico City was lost. No estimate
was possible about when the service would be restored. Telephone communications
within Mexico City appeared to be completely operational.
Very little damage was reported to the pipes carrying sewage for Mexico City.
The most likely areas where damage might have occurred would be where water
distribution lines were damaged. Because sewage lines were inactive due to lack of
water, thorough damage assessment could not be made by the relevant officials.
No significant damage to streets and bridges within Mexico was found. Minor
buckling of pavements was observed in the lake area due primarily to previous ex-
cavation in these areas.
Airports in Mexico City were not damaged and were operational the day after the
IMPLICATION5 FOR RE5EARCH RELATED TO PUBLIC SAFETY
The tragic experience of Mexico provides invaluable data for improving earth-
quake engineering construction and emergency response for the international com-
munity. To derive the optimum benefit for avoiding futrue catastrophes from this
experience, certain projects ought to be implemented as soon as possible.
Thanks to the University of California-San Diego/National University of Mexico
network in the epicentral area, this earthquake has yielded the richest collection of
strong motion data ever obtained from the movement of a subduction type fault.
Also, because of the strong motion accelerograph network maintained by the Na-
tional University of Mexico, we have a reasonably good idea of the types of strong
motion observed in the city. Analyzing the information in order to understand the
nature of the rupture phenomenon and the attenuation and amplification phenom-
ena would help improve our ability to estimate strong motion significantly.
Because of the confusion created by rescue efforts, it has not yet been possible to
make an orderly investigation of the contribution of foundation failures to building
failure. It seems to be urgent to establish the possible causes and instances of foun-
dation failure and to relate the overall building behavior to amplification studies.
Reiforced concrete construction
Much of the damage in town occurred in reasonably modern or recently built re-
inforced concrete construction. The specific causes of failure must be understood in
order to avoid similar catastrophes in the United States.
Damage to steel construction
Mexico City was the seat of failure of a modern structural steel 21 story building.
Because cities in seismic regions of the world have a significant amount of structur-
al steel construction in this level, it is essential to establish the causes of failure of
this building and to make necessary improvements in specifications.
Building code enforcement
It is well known that Mexico has a building code that would be considered to be
one of the best in the world. The relationship between the building code and the
actual buildings needs to be investigated.
Most hospital systems in the United States, notably the Veterans Administration
system, have been very carefully evaluated for earthquake resistance. It is therefore
hoped that a similar disaster would not befall the U.S. system again as it did in
1971. Nevertheless, it would be of great importance to study the methods which
have been used in evaluating the VA and other hospitals in relation to the failures
that occurred in Mexico City.
It would seem that hundreds of lives might have been saved in Mexico City if the
correct equipment and experienced people had been available. Thinking the ex-
tremes of possibilities, it is important to test whether in our major cities, especially
in those such as St. Louis and Charleston, we have the capability to lift heavy slabs
in a matter of hours in order to save survivors of building collapses.
Evaluation of existing buildings
The failure of buildings constructed before 1957 and of the relatively new hospital
buildings emphasizes the current state of the knowledge and performance on build-
ing safety evaluation. In view of the large inventory of buildings constructed before
modern codes in seismic areas of the world, it would seem proper to reinforce the
research and development effort in the area of strength evaluation, a task consider-
ably more difficult than design and construction of new earthquake-resistant build-
The 19 September 1985 tragedy of Mexico has many dimensions that will come
into focus as the data settle. However, one conclusion from it seems clear and domi-
nant even at this early date after the event. Mexico City was subjected to a ground
motion with an intensity beyond the extremes of the anticipated intensity. We must
be prepared for the extremes of the expectable. Vulnerability of cities such as St.
Louis, Memphis, and Charleston have become less unreal since 19 September 1985.
Much of the data reported were obtained and/or confirmed by members of the
first group of earthquake professionals dispatched to Mexico City after the earth-
quake jointly by the National Academy of Sciences, the Earthquake Engineering Re-
search Institute, American Society of Civil Engineers Technical Committee on Life-
line Earthquake Engineering, the National Science Foundation, and the Seismic
Qualification Utilities Group. Members of this group were: Dr. James Brune, Spe-
cialty: Seismology; Mr. Edwin Johnson, Specialty: Structural Engineering; Dr. Ellis
Krinitzsky, Speicalty: Geotechnical Engineering; Mr. Paul Flores, Specialty: Social
Sciences/Emergency Response; and Mr. Luis Escalante, Specialty: Lifelines.
I am indebted to Ambassador Gavin and his staff at Mexico City for their gener-
ous and efficient support of the activities of the survey group.
Members of the Engineering Institute, National Autonomous University of
Mexico, esepcially Jorge Prince, Luis Esteva, and Emilio Rosenblueth, cooperated
fully with the survey group. Their cooperation was crucial to the success of the mis-
Preliminary (manual) digitization and response calculations were made by Sharon
Wood, Ricky Lopez, and Marc Eberhard, staff members of NSF Project ECE 84-
M~iIi~ City Igiiigtgd S6OE gF1iiiid Figtii!t
.g 0.0 10.0 20.0 30.0 40.0 50.0 60.0
Fig. 1 S6OE C~pF1F1t if GF1F1d A iliF1tSCCi Dii F1iF1d Diii S iiid E CpF1iS~
tliiiF1d SCT ii Miiiii City (liii Isissisi iii if Xiii iid Dii~,iiidid)
211 RESPONSE SPECTRUM
0.0 0.5 1.0 1.5 2.0 2.5 3.0
Fig. 3 5. SiiiiiF1 if iiifi Ri$PCC$i fi~ thi Sir SlitiCi (Disyitri Finn 50, 56(E)
MEXICO CITY - SEP 1985
Senator GORTON. Thank you, Doctor.
Mr. FLORES. Thank you, Mr. Chairman.
I was also part of the same team that accompanied Dr. Sozen. I
was to look at and observe the emergency management aspects of
the disaster as well as the societal response.
I would like to make some reference to a report issued in 1981 by
the National Security Council and the Federal Emergency Manage-
ment Agency that indicated that California was woefully unpre-
pared for the consequences of a catastrophic earthquake impacting
one of its metropolitan regions.
I think a similar assessment could probably have been made of
Mexico City, but obviously their time right now is September 19
and 20. Certainly socioeconomic conditions there made prepared-
ness efforts more difficult to carry out.
For purposes of this hearing, I would like to provide your com-
mittee an initial assessment of the Mexico City earthquake disaster
by discussing the areas of hazards reduction in preparedness, emer-
gency management and reconstruction, and identifying some impli-
cations for the United States.
Regarding preparedness, I think programs to educate the public
in Mexico were in need of greater support before the quake. The
department established to develop such programs was cut by the
current administration for austerity reasons most likely. I think
the implication for us is that public education and information pro-
grams underway in the United States are raising the overall
awareness of the population, but I think there are some next steps,
and these should be toward mobilizing preparedness and self-help
at the community level, which will be more difficult to do. These
next steps will be more complicated and will require greater com-
mitment on the part of government and community leaders.
As far as hazards reduction programs, in all fairness to Mexico,
programs of these types are difficult to design and costly to carry
out, but there is no question that such programs in the aftermath
of a catastrophic earthquake prove to be cost effective.
Mexico now faces billions of dollars' worth of physical losses and
staggering social losses in human lives, suffering, and disruption to
the conduct of their social affairs.
In the United States, hazard reduction programs are only in the
developmental stages, with only a few local jurisdictions actually
having some programs in place. These programs can be a costly
burden to local government and must be supported by the States
and the Federal Government directly with financial assistance, or
indirectly through incentives.
As is the case in any large metropolitan area exposed to seismic
risk, the appropriate level for preparedness action is the local level.
Even though Mexico City may be considered to be administered or
managed by the national government, in the final analysis it is not
much differently administered than most of our own metropolitan
Local governments must be provided more support to carry out
long-term hazards reduction and preparedness programs and
should be more involved in directly planning such programs. Given
the complexity of our large metropolitan areas with many autono-
mous jurisdictions within an urbanized area, perhaps a regional ap-
proach would be appropriate.
Regarding emergency response, Mexico City's response was ex-
hilarating on the one hand and extremely problematic on the
other. Search and rescue efforts in Mexico City took some time in
getting organized. Whether or not a faster response would have
saved more lives is a question that merits further study, but there
is no doubt that the number rescued in the immediate hours after
the earthquake was due to the tremendous response of the public
itself. There were many heroes in those hours.
But a critical period was reached in the search and rescue effort
when organization and technical expertise were of the utmost ne-
cessity. Mexico is not alone in its need for more effective methods
of urban search and rescue. In the United States, we too need dedi-
cated special training programs to upgrade our capability in that
emergency response function.
During the Mexico City disaster it was evident that a multidisci-
plinary team was required for expeditious rescues to be made. En-
gineers, medical and fire personnel should have been working to-
gether as a team as the efforts to rescue victims alive became more
critical. The experience in Mexico City provides us here in the
United States with the necessary base by which to structure urban
search and rescue training programs.
Damage assessment and communications in Mexico City also
proved to be problematic. The importance of communications in
managing an extremely large disaster is not only related to hard-
ware, but just as importantly, it is related to the collection and
processing of assessment information. Many decisions have to be
made during a major disaster and should be based on the best in-
formation available at that moment. In Mexico City, even a few
days after the earthquake, it was not clear that a comprehensive
assessment had yet been formulated on which prudent decisions
could be made.
Initial government estimates were underestimated, yet that did
not have to be the case if better methods for collecting emergency
information and estimating damage and losses had been in place
before the earthquake occurrence. Utilizing such methods can be of
particular importance when communications hardware fail.
In the United States, emergency information management sys-
tems are only at a proposal stage. Feasibility studies have been
conducted and recommendations have been made, but such systems
are yet to be built. A basic reason for not having the systems in
place is cost, yet the costs of mismanaging emergency information
could be staggering. Each metropolitan region in the United States
should have an information management system in place that can
integrate hazard analysis information, inventories of buildings at
risk, and emergency management resources to utilize in the devel-
opment of hazard reduction programs, in actually managing the
disaster, and in planning reconstruction.
The Mexico City earthquake disaster, for us in the U.S. points to
the need to develop better training programs based on what we
learned from that tragedy. Urban search and rescue is only one
area that merits further study for application.
The need to understand the seismic risk in our metropolitan re.
gions is also important, but more important is the application of
that understanding and knowledge in reducing our hazards and in
improving our emergency management capability.
Regarding postearthquake reconstruction, the reconstruction in
central Mexico City, the area most affected by the earthquake, will
be a slow process. Mexico City is just beginning to systematically
collect information on the consequences of the earthquake on its
people, environment, and economy. This evaluation process will
necessarily take time but hopefully will be completed before major
decisions are made on how best to reconstruct.
This principle will be as important and applicable to the United
States should we be faced with such a disaster in the future as it is
to Mexico City now. Earthquake disasters of this magnitude also
provide opportunities. Those opportunities that are in the public's
best interests should be exploited, but only when tangible data is in
hand and all the alternatives have been weighed. For Mexico City,
necessarily moving slow may be an opportunity in and of itself.
In the United States we must learn all we can from how Mexico
City reconstructs. We can also assist Mexico initially, not with
pledges of millions of dollars for the physical reconstruction, but
with lower cost research to determine the full implications of the
disaster, both social and economic. Our own research efforts of this
great disaster should be of a collaborative nature, assisting to the
extent that we can with support to private and public research in-
stitutions in Mexico that recognize the need to study the impact of
this disaster, so as to have a base for proposing sound alternatives
to the problem of socioeconomic and physical reconstruction.
Senator GORTON. Mr. Flores, thank you.
Let me ask you a what if. If there were an earthquake in the
metropolitan Los Angeles region which caused the same amount of
physical damage as the Mexico City earthquake, would your orga-
nization, would southern California, be better prepared to deal
with that from the point of view of its immediate postearthquake
response, finding and saving of victims who could be saved and the
Do you have a plan in place there in southern California to deal
with this kind of an emergency in a measurably more effective
Mr. FLORES. We do not have a plan per se. Each local jurisdiction
must have its own plan in place. We do not have a regional plan,
and we should, perhaps, of how those local jurisdictions must need
to coordinate with each other. This year our particular project is
addressing that issue, but it is a political one, getting local jurisdic-
tions to work together with a common base. It is a difficult process.
But I do think that it is important. It is not enough to think that
the State or the Federal Government will come in and solve all the
problems. The major problems need to be solved by the local juris-
dictions themselves, and I think greater effort needs to be put into
Senator GORTON. Dr. Sozen, do you have any insight yet into how
much this earthquake was simply an experience from which
Mexico City and we must learn something with respect to the con-
struction and maintenance of buildings? How much of the damage
that occurred could have been avoided with the building codes that
were in place, and was not avoided either because the codes were
ignored or not enforced?
Mr. SOZEN. I never got the feeling that their building codes were
ignored, and I did say that their building codes anticipated this
type of motion, but not its intensity.
Senator GORTON. So primarily what we have learned from this is
that this kind of quake is likely to be much more intense than we
had previously anticipated.
Mr. SOZEN. That is my general impression from my conversations
with Mexican engineers before the event and after the event, that
it was the intensity that they could not estimate.
As a matter of fact, if you look at the distribution of damage in
the 1957 earthquake, its location with respect to the town and also
the types of buildings which were damaged, you find that the
damage this time was exactly in the same areas and exactly in the
same type of buildings, only this time-and here it is my own opin-
ion, it is not a scientific fact-the damage was about twice, maybe
three times as intense because of the rather rare nature of what
did happen over there.
And of course, from that I get a lesson which is really very im-
portant for us in that they did have some buildings which survived
the 1957 earthquake but not the 1985 earthquake.
Senator Gorton. Why?
Mr. SOZEN. Well, it is very difficult to evaluate the resistance of
buildings. It is much more, it is much easier to design a brand new
building to be earthquake resistant, never earthquake proof, but
earthquake, resistant, than to look at an existing building and say
what sort of an earthquake it will take. And I am afraid that is a
place where we have to do a lot of work, and here is a very good, if
tragic, opportunity in which we could improve our knowledge.
Senator GORTON. Thank you.
Senator GORE. Yes, just briefly, I would like to follow upon the
chairman's questions about codes. Mr. Flores, you were quoted as
faulting the enforcement of codes in Mexico City.
Mr. FLORES. I was?
Senator GORE. In the Washington Post, September 21. So let me
just read it to you, and you tell me if it is wrong. "Mexico City has
been working very hard to upgrade its building codes, but the codes
are one thing, and having the codes applied in the whole construc-
tion process is something else."
Maybe I am reading that wrong, but I got from that the impres-
sion that you felt that the application of the codes was deficient
even though the actual codes themselves might be adequate. Maybe
I read into that word application enforcement, but do you want to
tell me in your own words?
Mr. FLORES. Sure. I think that situation is just as a applicable to
us here in the United States. The application of the code, the con-
struction process, is very different than the design of the code
itself. In California, for example, the Seismic Safety Commission
felt that to be an important enough issue where they put out a
report emphasizing the importance of the construction process, of
inspection, to ensure compliance.
So I think worldwide that is an important issue that needs to be
I do not have-I am not an engineer, and I do not have the nec-
essary data to flatly say whether Mexico City is in some kind of
fault as far as application of the code. I just think it is an impor-
tant thing to look at.
Senator GORE. Yes.
Well, since this quake was so serious, should we then redouble
our efforts to make certain that these codes we spend so much time
designing are rigorously applied when construction actually takes
Mr. FLORES. I think that is a very prudent thing to do.
Senator GORE. All right, now, Dr. Sozen, I hesitate to get into
this area, but will you just very briefly explain to me the difference
between frequency and period?
Is "period" the word that applies to the swaying the building?
Mr. SOZEN. I am sorry. It was really my bad use of English. They
are one and the same.
Senator GORE. They are one and the same? All right.
Mr. SOZEN. In effect. Except that one is the reciprocal of the
other. If I say something has a frequency of four cycles per second,
it means it has a period of one-fourth of a second.
Senator GORE. All right, now I understand. All right, fine.
Mr. SOZEN. That is what it is.
Senator GORE. Now, both words can be applied to both the build-
Mr. SOZEN. And the ground motion.
Senator GORE. All right, I have it now.
Is there any way to predict the likely frequency of earthquakes
in particular areas?
Mr. SOZEN. In Mexico City, certainly, but that is a very special
condition, and in other parts of the United States, like San Francis-
co, St. Louis, and so forth, we do not have the same sort of periodic-
ity, at least I should say we have not observed it before. It is more
of a random motion. It is a mix of frequencies rather than a single
one. But indeed, on a general basis we have a reasonably good un-
derstanding of what type of ground motion to expect in various
parts of the country.
It is when that we do not quite understand.
Senator GORE. Now, in the New Madrid area, is there any way to
predict the periodicity of quakes in that area? Is there a consistent
Mr. SOZEN. First, I am really getting out of my area of expertise.
I must qualify my remarks by saying that, but I expect that when
the energy release comes from the New Madrid earthquake, the
type of motion that we are going to see, say, in St. Louis or Carbon-
dale, IL, is not likely to be the one that we saw in Mexico City. It
will be a different collection of frequencies, and of course, we do
not know enough because we really have not taken those parts of
the country as seriously as we have California and Seattle.
Senator GORE. But that is a mistake, is it not?
Mr. SOZEN. It seems to me more of a mistake than it did before
September 19, yes, sir.
Senator GORE. Thank you very much.
Senator GORTON. Thank you both very much. We appreciate your
The third panel is Dr. Herrmann, Ms. Noson, and Dr. Johnston.
Dr. Johnston I understand has a plane relatively soon, so we will
change our order and let him start.
And again, for all three of you, your written statements we have
from you will be included in the record as if read.
Dr. Johnston, please proceed.
STATEMENTS OF DR. ARCH C. JOHNSTON, DIRECTOR, TENNESSEE
EARTHQUAKE INFORMATION CENTER, MEMPHIS STATE UNI-
VERSITY; DR. ROBERT B. HERRMANN, PROFESSOR OF GEO-
PHYSICS, DEPARTMENT OF EARTH AND ATMOSPHERIC SCI-
ENCES; AND LINDA NOSON, SEISMOLOGIST, GEOPHYSICS PRO-
GRAM, UNIVERSITY OF WASHINGTON
Dr. JOHNSTON. Mr. Chairman, thank you.
It is a privilege to be here today, and I would like to make a few
brief remarks, giving a local perspective on earthquake prepared-
My home town is Memphis, TN, and there are some things, start-
ing there, I have to say, in the initial stages, which will be very
important for the future.
Let me start by pointing out a difference between seismic hazard
and seismic risk. The two are not really synonymous. I distinguish
them by the question, Can actions of people have any effect on the
situation? Hazard cannot be lessened or increased, but risk can. In
other words, the earthquake hazard in Memphis is an inheritance
of geographic location, its proximity to the New Madrid zone. Since
we cannot control earthquakes, we cannot change the hazard, but
we can do a great deal about earthquake risk. In Memphis, the
danger posed to the population can be substantially altered by a
number of actions, most significantly, by improved construction
and siting of buildings.
Now, in that regard, let me make the following very rough com-
parison between Memphis and Mexico City. Mexico City is a major
city located near a highly active seismic zone that is capable of
very destructive earthquakes. Memphis is a large city located very
close to a moderately active seismic zone capable of producing very
Mexico City is built on unconsolidated soil, the alluvial fill of an
ancient lake bed, and that adds greatly to the seismic risk of the
city. Memphis is built on the unconsolidated soil in the Mississippi
River Valley, and that is an important additional seismic risk
factor for the city.
Mexico City had incorporated seismic resistance requirements
into its building codes. Many of its buildings survived the recent
quakes with minimal damage. However, many older buildings and
poorly constructed buildings either collapsed or suffered heavy
damage. At present, Memphis has no seismic requirements in force
in its building codes. Although it has many well-built buildings,
there are also many old and unreinforced masonry structures. No
Memphis building has ever been tested by a major earthquake.
This comparison cannot be pushed too far. The destructive earth-
quakes recur along the segments of the Mexican seismic zone about
every 30 to 50 years, and that is a much greater frequency than
destructive earthquakes in New Madrid, central United States. The
soil conditions for Mexico City are probably considerably worse
than in Memphis, although Memphis is much worse off than, say,
St. Louis, which has a lot of bedrock for construction. And in Mem-
phis, a much higher proportion of Memphians live in relatively
safe wood frame housing.
However, this comparison does illustrate that seismic risk in the
United States is a fact of life, and it is not just for the Western
Now, in my written statement, I name a number of actions that
have really already been touched on here today-the Central U.S.
Earthquake Consortium, the participation of the local emergency
response agencies, and the State agencies. So let me skip to what I
consider the most important development for the Memphis area,
and that is the local building code initiative.
As was pointed out in earlier testimony, building codes are en-
forced locally. There are no Federal or State requirements of what
goes into a community's building code. And communities in the
Central or Eastern United States have not enforced seismic re-
quirements in their codes.
Now, in Memphis, the Memphis and Shelby County Building
Code Advisory Board in late 1984 created a special committee, and
its charge was to formulate recommendations for implementing
seismic provisions in the recently combined city and county build-
ing code. The chairman of the committee was Mr. Warner Howe, a
professional engineer who currently serves as chairman of the
Building Seismic Safety Council and is a former director of the Na-
tional Institute of Building Sciences, and is a resident of Memphis.
The special committee's work is nearly complete, and a set of
recommendations will be submitted to the advisory board this fall
for consideration for adoption by the Memphis City Council in the
Now, even though the formation of the special committee is only
an early initial step, I believe it is of great importance. As the
recent Mexican quake graphically showed, it is buildings that kill
people in earthquakes. The recent FEMA study which has already
been mentioned this morning found that for the smaller of its two
earthquakes, one of magnitude 7.6 occurring in the daytime when
people are out of the wood frame houses and into other buildings,
the deaths could range from about 2,500 up to for the maximum
earthquake, up to about a 5,000 figure. A significant part of this is
that the study also estimated that about 26 percent, or almost a
third of the total casualties, would be school children and teachers
if the quake occurred during school hours.
There was an excellent study also by the Federal Government,
Department of Housing and Urban Development, in 1974 that actu-
ally went a step further than this recent FEMA study in that it
estimated how much you could reduce the casualties and building
losses if seismic code provisions were implemented. The estimates
were that if seismic code requirements had been put in in 1970 and
a major earthquake happened 50 years later, the year 2020, it
could reduce deaths by 40 percent and building losses by 35 per-
cent. This was with a strategy that required no retrofitting of
So the committee's work has placed a heavy emphasis on design
of a practical, workable code. The major hurdle is to get the code
adopted. For example, the committee has not recommended retro-
fitting at the present time. It is felt that you need to walk before
you run. They also require a variable standard in that not all
buildings are given the same requirements of seismic resistance.
Buildings designated as critical or high occupancy structures would
be held to higher code requirements than, say, warehouses, storage
areas, and the like. In this fashion, we feel that a code can be im-
plemented that is not overly restrictive, is not economicaly burden-
some, and can be implemented, and as more and more older build-
ings are gradually replaced by new buildings designed to the new
code, seismic risk in Memphis can be substantially reduced.
[The statement follows:]
STATEMENT OF ARCH C. JOHNSTON, ASSOCIATE PROFESSOR OF GEOLOGICAL SCIENCES
AND DIRECTOR OF THE TENNESSEE EARTHQUAKE INFORMATION CENTER, MEMPHIS
Mr. Chairman, members of the subcommittee, it is a privilege to be asked here
today to give a few brief remarks about the state of earthquake preparedness in the
United States in general and in the Memphis, Tennessee area in particular. In the
wake of the Mexico City tragedy this question assumes an urgency that is generally
lacking during more normal times. However, since preparedness must, by definition,
be accomplished before rather than after the fact, it is the actions we take during
normal times that are of critical importance. Such action is hindered by the nature
of the earthquake threat: we must prepare for an event of poorly estimated propor-
tions that will occur at some nebulously defined time in the future. But no one in
this room today or in the nation at large should doubt that sooner or later a large
U.S. city will be subjected to a large, destructive earthquake.
In this testimony I would like to address some preparedness measures that are
taken at the local and state level in Memphis, Tennessee, where public awareness
of, and concern about, seismic hazard is much below that on the west coast. I chose
Memphis for this not only because I live there, but also because in a number of
recent studies Memphis has been identified as the highest seismic risk city east of
the Rocky Mountains. In this regard, consider the following comparisons with
Mexico City is a major city located near a highly active seismic zone, capable of
producing very destructive earthquakes.
Memphis is a large city located very close to a moderately active seismic zone,
capable of producing very destructive earthquakes.
Mexico City is built on unconsolidated soil-the alluvial fill of an ancient lake
bed-which adds greatly to the seismic risk of the city.
Memphis is built on the unconsolidated soil of the Mississippi River Valley, which
is an important additional seismic risk factor for the city.
Mexico City has incorporated seismic resistance factors into its building codes.
Many of its buildings survived the recent quake with minimal damage. However,
many older buildings and poorly constructed buildings either collapsed or suffered
Memphis enforces no seismic requirements in its building codes. Although it has
many well built buildings, there are also many old and unreinforced masonry struc-
tures. No Memphis building has ever been tested by a major earthquake.
The above comparison cannot be pushed too far. Destructive earthquakes occur
with much greater frequency in Mexico than we believe is the case for the New
Madrid seismic zone. Soil conditions for Mexico City are considerably worse than in
Memphis, although Memphis is much worse off in this regard than, say, St. Louis. A
much higher proportion of Memphians live in relatively safe wood frame housing.
However, the comparison does serve to illustrate that seismic risk in the United
States is a fact of life that cannot be ignored and that this holds true for regions
other than the western U.S.
EARTHQUAKE PREPAREDNE5S IN MEMPHIS, TN
There is a semantic difference between seismic hazard and seismic risk; the two
are not synonymous. They are most easily distinguished with the question "can the
actions of people have any effect on the situation?". Hazard cannot be lessened or
increased but risk can. The earthquake hazard in Memphis is an inheritance of geo-
graphic location and is due to the city's proximity to the New Madrid seismic zone.
Earthquake risk in Memphis is the danger posed to the population and can be sub-
stantially altered by a number of actions, most significantly, the improved construc-
tion and siting of buildings.
If we accept that a non-negligible seismic hazard exists for Memphis, it is then
fair to ask what, if anything, is being done to minimize the risk. Prior to the 1980's
the answer to this question would have been "absolutely nothing". This is not great-
ly surprising since the New Madrid zone has been very quiet this century compared
to the massive earthquakes it produced in the nineteenth century. Earthquakes do
not make themselves a part of the fabric of life in the central U.S. An excellent
study on the earthquake risk in Memphis [the MATCOG Report] sponsored by the
Department of Housing and Urban Development in 1974 has gone virtually unheed-
ed by the city.
The state of preparedness in Memphis has improved considerably in the last five
years through initiatives of the federal, state and, perhaps most importantly, the
local Memphis government. The state established the Tennessee Earthquake Infor-
mation Center at Memphis State University in the late seventies. One of its most
important projects has been the implemenation of an Earthquake Education Center
(EEC), one of three prototypes in the nation (the others are in Charleston, SC and
Seattle, WA). These EEC's are sponsored by the Federal Emergency Management
Agency. Their objectives are to actively involve citizens in earthquake preparedness
projects and to generally elevate the public's awareness of the earthquake risk in
The Memphis EEC, beginning its third and final year of FEMA support, has made
a marked difference. A city- and county-wide earthquake safety week was held for
the first time in February, 1985 and proclaimed by both mayors. Significant pre-
paredness projects have been developed with the public school system, a particularly
vulnerable population, and with the Memphis hospitals. A large and increasing
number of earthquake and earthquake-related stories are being reported in the
Memphis media-television, radio and newspapers.
The unique and difficult problems created by the occurrence of a large earth-
quake are now recognized by TEMA (The Tennessee Emergency Management
Agency), and earthquake response planning is now an integral part of their mission.
TEMA has formed a statewide Seismic Advisory Panel to help guide their activities
in this area. TEMA also actively participates in the Central United States Earth-
quake Consortium (CUSEC), an umbrella emergency response organization with
membership from the seven states for which a large New Madrid earthquake would
have the highest impact.
A LOCAL BUILDING CODE INITIATIVE
I will end my statement by describing what I consider the most important devel-
opment of all in reducing the earthquake risk in Memphis. This was the creation by
the Memphis and Shelby County Building Code Advisory Board in late-1984 of a spe-
cial committee charged to formulate recommendations for implementng seismic pro-
visions in the combined city-county building code. The chairman of the committee is
Mr. Warner Howe, a professional engineer, who currently serves as Chairman of the
Building Seismic Safety Council and is a former director of the National Institute of
Building Sciences. The special committee's work is nearly complete and a set of rec-
ommendations will be submitted to the Advisory Board this fall. Consideration for
adoption by the Memphis City Council is the next step.
Even though the information of this special committee is only an early, initial
step, I believe it will prove to be of great importance. As the recent Mexican quake
so graphically showed, it is buildings that kill people in earthquakes. The recent
FEMA study by Allen and Hoshall, Inc. found that a major daytime New Madrid
earthquake (M>7.5) would cause an estimated 2500-4000 deaths in Memphis. If the
quake happened during school hours 26% of total casualties would be school chil-
dren and teachers. The 1974 MATCOG study concluded that implementation of
strong seismic building code requirements in 1970 would reduce deaths by 40% and
building losses by 35% for a major daytime quake in the year 2020. This was for a
strategy that required no retrofitting of existing buildings.
The committee has placed heavy emphasis on the design of a practical, workable
code fitted to the seismic risk of the region. Adopting the California code require-
ments, for example, is indefensible economically when the chance that a Memphis
building will be subjected to strong seismic forces is much less than in California.
The committee instead has allowed the degree of required reinforcement to vary ac-
cording to the importance of the structure. For example, the attached seismic
zoning map from the American National Standard Institute places Memphis in seis-
mic Zone 3. instead of requiring all lateral strength computations to use Zone 3
values, a factory or warehouse would be allowed to use a Zone 2 or 1 designation,
while critical and high occupancy structures would be held to Zone 3. In this fashion
a code that is not overly restrictive nor economically burdensome can be implement-
ed. As more and more older buildings are gradually replaced by new buildings de-
signed to the code requirements, the seismic risk in Memphis can be substantially
Senator GORE. Mr. Chairman, thank you for yur courtesy in let-
ting me address questions to this witness out of order because I
want to make sure that he gets his plane back to Memphis. I do
And Dr. Johnston, I appreciate your testimony and the opportu-
nities we have had to work together in the past. In my opinion-it
is a little biased because we are friends-I think you do an out-
standing job, and I think your testimony again illustrates that fact.
You heard the testimony earlier from FEMA about this forth-
coming study. How accurate do you believe that estimate is which
he used of $33 billion and some 5,000 lives lost? Do you have any
way of assessing it?
Dr. JoHNsToN. Well, Senator, I do not have any of my own fig-
ures. I am familiar with that report, a draft version, and I think
those figures have been upgraded some from the draft version that
Map for Selaroic Zones - Contiguous 48 States
I am familiar with. That would be the worst case scenario of the
maximum possible earthquake, 8.6, occurring during daytime
school hours, I am sure. The likelihood of such an event is very
low, but those worst case figures I would not argue with. They are
based on a very extensive study.
Senator GORE. When you say the likelihood of that event is low,
you prepared some estimates on probability which I would like to
share with the committee and ask you to confirm.
The probability of an 8.3 earthquake prior to the year 2000 in
the Memphis area you estimate to be as low as 1 percent; over the
next 50 years, up to 4 percent; but when you get down to a 7.6-
degree earthquake, the probability goes up to almost 9 percent
before the year 2000, and almost 30 percent before the year 2035.
The probability of a 6.3-degree earthquake on the Richter scale is
as high as 63 percent in this century, 40 to 63 percent before the
year 2000, and 86 to 97 percent before the year 2035.
How much damage would be done from a 6.3 earthquake in
Dr. JOHNSTON. That would depend a great deal on whether it
happened in the northern or southern portion of the New Madrid,
which runs from northeast Arkansas up into Missouri. You can see
that in terms of energy release. A magnitude 6.3 is nearly a thou-
sand times less than an 8.3 because the magnitude scale is expo-
nential. So you are talking about two quite different events, and I
would emphasize that.
But a 6.3 can be quite destructive if it happens very close to a
population center. The 1971 San Fernando earthquake was a 6.3-
6.4, and it did over a half a billion dollars worth of damage and
killed, I forget the number, close to 100 people. So if a 6.3 happened
on the southern portion of the New Madrid zone, which comes to
within about 35 miles of Memphis, it would be destructive in the
city. It would not be a catastrophe, but it would be destructive, and
there would be casualties and loss of life.
Senator GORE. All right.
Now, one of the things we need is better data. We need a better
way to absorb and organize the data that we have.
How important in your view are the seismic data networks?
Dr. JOHNSTON. Well, as a seismologist, they are very important.
They are really the basis, the core of all we do in understanding
the earthquake process. We really talked about two different as-
pects of the earthquake problem here today: the basic research, un-
derstanding earthquakes themselves, and then the applied portion.
Both are equally important, and one without the other is not going
to be very effective. So for the basic earthquake research going on,
the networks are the backbone of the process.
Senator GORE. What improvements could be made in the data
Dr. JOHNSTON. Well, they are expensive. They have to run con-
tinuously, 24 hours a day, and you need a lot of stations distributed
geographically to really pin down the earthquake occurrences.
They generate a huge volume of data that is right now not central-
ized. It is not-I would have to say not fully utilized to the extent it
could be. So I think a centralized data center would be very impor-
And also, the networks really lead sort of a hand-to-mouth exist-
ence. The funding for them is not secure. It is distributed amongst
a number of different agencies, and as one of the network opera-
tors, I would like to see long term secure and stable funding.
Senator GORE. Well, very good. I will close on that because my
time has expired.
Mr. Chairman, I just want to note for the record that one of the
most constructive actions we could take in response to the testimo-
ny we have heard today might well be to cause to stimulate some
improvements in this seismic data network, and in particular, to
improve our capacity to process the enormous amounts of data col-
lected, organize that data a little bit better, and make it more
useful to seismologists in their efforts to try to improve the predic-
tions of earthquakes and earthquake damage.
But again, Dr. Johnston, I certainy appreciate your presence
here today and hope you have a safe flight back to Memphis.
Senator GORTON. Thank you, Dr. Johnston We will excuse you
now, with our gratitude.
Dr. JOHNSTON. Actually, I have a little more time, and I would
like to hear the remaining testimony.
Senator GORTON. We would be happy to have you stay.
Dr. HERRMANN. Thank you, Mr. Chairman.
I would like to review the state of knowledge about and prepara-
tion for earthquakes in the Central Mississippi Valley. This region
includes seismically active and potentially affected portions of
about seven neighboring states within a 200 mile radius of New
Madrid, which as we have heard before is the locale of the destruc-
tive earthquakes during the winter of 1811 and 1812.
I would like to point out that our awareness and concern about
earthquakes in the area is not entirely due to the occurrence of
those earthquakes in 1811 and 1812, as is evidenced by the loca-
tions of historical earthquakes. Even without the earthquakes of
1811 and 1812, we would still be worried about large earthquakes
down in New Madrid. Large earthquakes have occurred in 1843
near Memphis and in 1895 near the confluence of the Ohio and the
Mississippi Rivers. In addition, many other earthquakes have oc-
curred in the area which have caused damage in the immediate vi-
cinity of their occurrence.
The point I would like to make is that very large earthquakes
have occurred in the region in the past 200 years, that the region is
still seismically active, and that from our knowledge of geological
processes, it is unwise to presume that we do not need to worry
about large earthquakes in the future.
Fortunately, State and local governments are becoming aware of
the earthquake threat and are beginning to prepare their response
to the problem as a result of educational efforts of the U.S. Geologi-
cal Survey and the Federal Emergency Management Agency. State
agencies are preparing earthquake disaster response plans and are
involving the Red Cross and other organizations in planning and
training. Federal agencies such as the U.S. Nuclear Regulatory
Commission, the U.S. Army Corps of Engineers, and the Veterans'
Administration are taking steps to ensure the safety of the struc-
tures for which they are responsible. In addition, some of the
newer buildings now being built have a seismic design element.
I will not dwell on the disastrous consequences of a recurrence of
a major earthquake such as those of 1811 and 1812 primarily be-
cause a recurrence in the immediate future is not as likely as
smaller but still damaging earthquakes. This judgment is based on
an extrapolation of the activity rates of smaller earthquakes, and is
open to possible error.
Our knowledge of the earthquake process is not as advanced as
in California because the active portion of the fault associated with
the New Madrid earthquakes is buried under 3,000 to 10,000 feet of
Mississippi River alluvial deposits and cannot be directly exam-
ined. It is enough to say that such earthquakes would cause major
damage in the cities of Memphis and in St. Louis, disrupt Mississip-
pi River transportation, disrupt east-west transportation along
interstate highways, and damage the many oil and natural gas
pipelines passing through this portion of the Mississippi Valley
which service in turn the major metropolitan areas of the Midwest
and the east coast. In other words, a recurrence of the 1811-12
earthquakes would be a major disaster.
What we do anticipate with some confidence is a recurrence of
an earthquake as large as the 1843 or 1895 earthquakes. Dr. John-
ston has recently estimated that there is about a 50-percent chance
that such an earthquake or an earthquake with magnitude greater
than 6 would occur somewhere in the region in the next 15 years.
This earthquake would certainly be smaller in magnitude than the
magnitude 8.5 New Madrid earthquakes of 1811-12, but would still
be large enough to cause substantial damage immediately near the
earthquake itself, and depending where the earthquake would
occur in the New Madrid seismic zone, would cause building
damage in St. Louis or Memphis, depending, of course, on the near-
ness of the earthquake to these cities. There would be a substantial
region of minor damage, such as broken chimneys, which would
affect the occupants of thousands of homes.
I might mention that there was what seismologists would call a
small earthquake in northern Kentucky in 1981, about a magni-
tude 5 earthquake. That caused several million dollars worth of
damage primarily to individual homes with broken chimneys.
The results of extensive interdisciplinary scientific research
during the past 10 years have been used to increase public aware-
ness of the earthquake problem. However, the scientific input has
the potential for being improved in the future. Improvements are
required in the estimation of the ground shaking due to an expect-
ed earthquake. This in turn requires additional knowledge of the
location and size of the expected earthquake, a better understand-
ing of how the earthquake causes shaking at a particular point for
given foundation conditions, and a better understanding of the re-
currence rates of large earthquakes. These improvements hinge di-
rectly upon an ability to detect and record all earthquakes that do
The result of dense monitoring near New Madrid since 1974 is
best seen in figures 3 and 4, in which the locations of 2500 earth-
quakes are plotted. The significantly improved resolution due to a
dense seismic network led to more precise locations and depths for
the earthquakes. A set of linear fault segments are evident, which
are not seen in the historical data of figure 1. While this is an im-
provement over the historical picture, much is lacking that affects
our understanding of the earthquake process. Part of this is due to
the very short history of dense observation in the central United
States and part is due to the rate of seismic activity, which is
lowerer than many parts of California. The low activity rate not
only indicates a reduced earthquake threat, but also requires that
our networks have to operate longer to fully understand the earth-
The need to consider the earthquake problem in the design of
critical facilities is acknowledged, but the interests of Federal agen-
cies change as the agency mission changes. We thus have the prob-
lem that many agencies want to use the data and research result-
ing from these networks but at the same time cannot contribute
the long term support needed to maintain the required flow of sci-
entific observations. The earthquake problem will not go away. The
fact that it has a major impact on the estimation of geologic haz-
ards guarantees this. This is indicated by an observation that 20
years ago little thought was given to the seismic resistant design of
hospitals and power plants in the country, while today aseismic
design is required for waste disposal projects not even thought of
20 years ago. We are continually running into geologic problems
that require estimates of what is likely to happen in the next 50,
100, or 1,000 years.
Because the consequences of large earthquakes will affect the
economy and defense of this nation as long as it exists, stable, con-
tinuous monitoring is essential.
We are facing major problems with respect to our ability to mon-
itor these earthquakes and to be able to learn everything possible
about them. The problems are due to our ability to continue to ac-
quire and analyze seismic data.
The first requirement that the scientific community would need
is that we would require stable and long term monitoring of the
seismic activity. The other requirement that certainly is needed is
that our methods for estimating the ground motion due to any
earthquake must be improved.
The Mexican earthquake points out the very disastrous effects of
a large earthquake at large distances. The damaging effect of low
level ground motion of long duration has not really been appreciat-
ed before. This will be even more of a problem in the central
United States in which it is known that seismic waves are trans-
mitted very efficiently over large distances.
Much emphasis in strong ground motion has been directed
toward understanding the large motions near the fault itself, but
little has been done to investigate the motions at large distances.
In the Central United States, a research program stressing both
theoretical and observational techniques is required in order to es-
timate more precisely the expected ground motion. At present, we
have some approximate estimates, which have substantial uncer-
tainty, which affects our ability to properly design structures to
resist earthquakes and to assess the potential for earthquake
In conclusion, much has been accomplished in the central United
States in the last 10 years, especially despite essentially level fund-
ing in the earthquake hazard studies for the last few years. Much
more can be done by the scientific community in the future given
modest improvements in our ability to acquire and analyze seismic
[The attachments referred to follow:]
Figure 1 Plot of earthquakes large enough to he felt and reported io the Central United States
ninee 1800. Damaging earthquakes have occurred near New Madrid, Missouri, Anna,
Ohio, in the Wabash River Valley and in Kansas and Oklahoma
Figure 2. Expanded plot of l,istorical eartl,qoakes in tl,e Central Mississippi \`allcy. Tl,e n,ajority
of historical Central United States earth quakes have occurred at tl,cse locat,o,,s.
Figaro 3. Earthqoakes located using a dense distribotion of highly sensitive seismographs operated
by Saint Look University, the Tennessee Earthquake Information Center, the Univer-
sity of Ecotocky and other individoal seismograph vtations. Nettaork operations are
primarily sponsored by the U. S. Geological Survey and the U. S. Nuclear Regulatory
Figure 4. Exyaodvd picture of rrceo t eactlrquakn activity. The h'ltsvivvi1,1ri River arid tire
Aekanvon-Missoori and Tennesvce-Kentacky haeders are shaarr. Caica, Illinois in
located at the top saheee the Mississippi Riser runs into tire map bacder schile
Memphis, Tennessee is located at tire bottom of tire map aluree the Mississippi River
crosses the bottom border. Blytlues-ille, Arkansas, site of a U. S. Air Force Bane, lien
directly above tire eeismteity patrvrrr at the Misvnari-Arbonsaa border.
Senator GORTON. Thank you.
Now, I should like to welcome my constituent, Ms. Noson, per-
haps the one of the furthest traveled of any of the people here
today, and we are happy to hear from you.
Ms. NosoN. Thank you.
I am Linda Noson, State seismologist, a position supported by the
University of Washington. I would like to express my appreciation
to this subcommittee for inviting me to comment on the implica-
tions of the recent Mexico earthquake disaster to earthquake haz-
ards within the United States.
My experience as state seismologist combined with seismological
and geological research activities has provided a unique opportuni-
ty to work closely with both the scientific community and those
seeking to use the information from that community.
Sixty percent of Washington State's population lives within seis-
mic risk zone 3, where major future earthquake damage is antici-
pated. The present delineation of Washington seismic risk zones ex-
cludes recent information on both earthquake data defining a
major zone of shallow earthquake activity in southwest Washing-
ton, and also excludes potential damage from a greater than mag-
nitude 8.0 earthquake off the coast of Washington, Oregon, or
northernmost California similar to the September 19 Mexico earth-
quake that is currently being considered as a possibility.
Because of the exclusion of these two seismic source zones, the
Washington earthquake damage estimates are extremely conserva-
tive. A much larger proportion of Washington State population
must now be considered at risk. In addition, unlike the shallower
activity in California, the earthquakes in the State of Washington,
generally the larger damaging ones, have occurred considerably
deeper and are felt over a much broader area. So similar to some of
the activity in the eastern part of the State, we have a fairly large
felt zone and affect a considerable area of the State when we have
The recent experience in Mexico underscores the extent of the
human tragedy involved in an earthquake disaster. It is imperative
to look closely at the situation to increase our own ability to pre-
vent or reduce the effects of such a disaster within the United
States. How well does the National Earthquake Hazards Reduction
Program 5-year plan address the difficulties encountered in
Mexico? It is my opinion that two elements of the National Earth-
quake Hazards Reduction Program plan closely related to loss of
life in Mexico are precisely those that are most inadequately devel-
oped within the State of Washington.
First, collection, synthesis and communication information
needed to better understand Washington earthquake hazards. The
importance of the collection and synthesis of information to better
understand and define earthquake hazards is illustrated by the
structural collapse of structures in Mexico City within local pockets
of high ground response. Even where information has been collect-
ed that could be used to develop Washington's site vulnerability
maps, few efforts have been carried out to synthesize that data in a
form useful to nontechnical users or to distribute the information
to those responsible for its application.
The severe damage in Mexico City was unrelated to surface
faulting and is a reminder of the importance of site vulnerability
studies that extend beyond the identification of active surface
faulting. Although dramatic damage can be caused by active sur-
face faulting, most earthquake damage, even in areas like Califor-
nia with numerous active surface faults, is caused by ground shak-
ing and its secondary effects.
Methods to define vulnerable sites need to be developed that in-
clude a range of parameters such as soil type, basement topogra-
phy, depth of bedrock, and past Modified Mercalli Intensity history.
Areas of higher relative ground response in Seattle, WA following
the 1949 and the 1965 earthquakes were not related to simple dis-
tribution of geologic materials. Most importantly, ongoing proce-
dures for information transfer need to be developed to communi-
cate earthquake hazard information to building officials, planners,
emergency responders, and other data users.
Two, the second area, preparedness planning and hazard aware-
ness programs. These programs are both inadequately developed
within Washington State and inadequately financed by the Nation-
al Earthquake Hazards Reduction Program Plan. Development and
implementation of State loss reduction strategies within areas only
infrequently subjected to major earthquake damage is inhibited by
a low perception and understanding by residents of what the haz-
ards are and what steps can be taken to reduce their effects. It is
necessary for State and Federal Government to provide direction in
the form of policy development and well defined State program pri-
Looking at the Mexico quake to explain the need for earthquake
planning and specific steps to reduce one's vulnerability to those
hazards, programs such as earthquake safety and education pro-
grams, these programs are needed both to explain to those people
that must apply codes and enforce codes the necessity for that code
development as well as steps to reduce their vulnerability to earth-
quake hazards, and included in there are more than just the vul-
nerability to structural hazards: loss of life in most U.S. earth-
quakes has commonly been caused by partial collapse or being
struck by nonstructural elements or building contents, and those
are relatively inexpensive areas to address in hazard mitigation
Two, strengthening of existing structures prior to improved
earthquake resistant design codes, 1960 in Washington State. In
the 1949 earthquake, $25 million damage was done. Over half of
that was to the state schools.
Initiation of hazard reduction focused on land use planning, de-
velopment of nontelephone dependent emergency communications
systems. One of the things that I felt I learned from the Mexico
experience is hams are going to be overloaded in the demands that
are placed upon them to respond to the communication needs. Our
hams in our area, I have contacted them with reference to commu-
nication system commitments after an earthquake, and they are
committed to almost every major agency available. So I think sys-
tems like schools and hospitals need to look at their own communi-
Guidelines for earthquake preparedness planning tailored to
meet the needs of local government, in translation and transfer of
relative scientific information. This is particularly important again
in the area of building codes. In the State of Washington there was
an NSF study looking at unreinforced masonry buildings within
historic districts, and it was found that in many cases codes were
not being enforced in the upgrade of these buildings because of a
lack of perception of the need and a real lack of understanding of
how to go about that enforcement.
The sobering fact that most loss of life during the recent Mexico
earthquake occurred within the first 5 minutes indicates the need
to improve pre-event hazard reduction efforts. Certainly, further
basic research on the fundamental causes and effects of earth-
quakes will improve our ability to forecast the where, how big, how
often, and how damaging of U.S. earthquakes.
The experience in Mexico, however, underscores the importance
of more effective use of the scientific information that has already
Senator GORTON. Thank you.
I would like to ask you one question, but to ask each of the other
two doctors to respond to it briefly as well.
As you look at the Federal program, the national program, what
element or elements in it have been most useful to you in your own
studies, and where, at the other end of the scale, do you find it
least adequate and most wanting?
Ms. NosoN. OK, I can start with the least adequate since I
touched that rather thoroughly here. If you look at the funding
levels for element 4, which is the preparedness planning and
hazard awareness section, it represents less than I believe 10 per-
cent of the budget, and that does appear to be an area of difficulty
in helping people both be motivated to take steps and also to know
and identify what those steps are.
Senator GORTON. Where has it been helpful to you?
Ms. NosoN. Where it has been helpful certainly in basic re-
search, fundamental research and defining what the source zones
for potential ground shaking in our State are, and that is certainly,
the seismic network has been extremely important. As I men-
tioned, there is recent data that came right out of the increase in
both seismicity and stations, they seem to flower together, around
Mount St. Helens in which we were able to define a source zone
previously unidentified, and that source zone of having a shallow
potential 6.5 magnitude earthquake makes us pause and wonder,
can we have such an event in a more populated area.
That is new information, and it does change how we are going to
both develop codes and how we are going to respond.
So that fundamental research has been probably the most impor-
tant for me in determining the likelihood and consequences.
Senator GORTON. Thank you.
Dr. HERRMANN. That is a very difficult question, Senator.
I cannot really respond to that, mostly because of lack of knowl-
edge of what is going on in the other programs. I was able to ob-
serve Response 85, the earthquake response exercise that took
place in June, this summer, in San Francisco in response to a po-
tential southern California earthquake, and I was quite impressed
in reading the preparatory documentation, all the work that had
gone into it and the scenarios they had for the training exercise.
I also realize that after the earthquake occurs, they do not really
need a seismologist anymore because it is in someone else's area of
expertise to worry about the response to the earthquake.
I think we certainly know more about earthquakes than we have
in the last, let's say, 10 years ago, when the program was first
started. There is much more to learn. We still are at the infancy in
our stage of being able to say that given an earthquake at this par-
ticular location, this is really what the ground motion would be at
some other place. There are errors in ground motion estimates. En-
gineers like to talk about confidence within a few percent in what
the ground motion is. Seismologists like to use another scale and
say that, well, we are within a factor of two or so. That is a major
difference for input to the design of structures.
I have seen the efforts of the U.S. Geological Survey and FEMA
in getting together local officials in encounter sessions to encour-
age people to worry about it. The sessions that have been put to-
gether in the Central United States are bearing fruit. We have to
remember that, as Dr. Johnston mentioned, that in this country
each local community can pretty much do what it wants to. And so
leadership by example that is required here rather than being able
to force anyone to do anything.
All in all, there has been a big improvement, but we are still
woefully unprepared to respond to an earthquake.
Senator GORTON. Thank you.
Dr. JOHNSTON. Well, I would just add to that that I think our un-
derstanding of the earthquakes that occur away from seismic zones
like Mexico and California, which is the case in the Central United
States, is a major problem. Our understanding is much less than
for those types of seismic zones, and most of the effort is going into
the plate boundary zones. Now, that is hard to argue with because
the seismic risk is higher in those areas, but we do need a major
improvement of our understanding of these midplate, midcontinent
Senator GORTON. But take the other half of my question.
Where are you reasonably satisfied with the national effort, or
where has it done the best job?
Dr. JOHNSTON. Well, I think that the effort to understand the
fundamentals of the earthquake process has been well supported in
the past. And this support seems to be constant and ongoing. So
most of, I would say, above 90 percent of the really dramatic
progress all the way back to the 1960's and the plate tectonics revo-
lution, is the result of Federal Government support.
Senator GORTON. Thank you all very, very much for coming, each
of you from some considerable distance, to help us in an extremely
serious and real challenge. We appreciate your help.
Our last panel includes Mr. Haber and Mr. Bragg. We are going
to hear from Mr. Bragg first.
Both of you have sat here patiently for a long time, though I
hope an interesting one. As you can see, we are well past our aim
for a closing time. In each case, your formal written statement will
be included in the record. If you can summarize it, it will be appre-
STATEMENTS OF JEFFREY S. BRAGG, ADMINISTRATOR, FEDERAL
INSURANCE ADMINISTRATION, FEDERAL EMERGENCY MAN-
AGEMENT AGENCY; AND JEROLD M. HABER, MANAGER, HAZ-
ARDS ENGINEERING DEPARTMENT, NATIONAL TECHNICAL
Mr. BRAGG. Thank you, Mr. Chairman. I will summarize my
comments and submit written testimony for the record.
I am pleased to be here with you this morning to present some
personal thoughts and observations on the earthquake insurance
issue. In 1981 FIA completed a study entitled "Earthquake Insur-
ance: A Public Policy Analysis." Now, I believe that my fellow pan-
elist will review that study in more detail, but one of the conclu-
sions that we reached as a result of that study was that Federal
intervention at this time in the earthquake insurance issue would
hamper progress that could be made by the private sector. The
study noted that there was an availability of earthquake insurance,
but that there was a significant failure to purchase the product. It
was suggested in the study that the Federal Insurance Administra-
tion do more to support public awareness of the earthquake insur-
ance crisis, but that leadership for this issue should come from the
For the past 4 years the Federal Insurance Administration has
attempted to implement that conclusion. We have encouraged the
industry not only to market earthquake insurance protection, but
also to suggest ways that an effective partnership may be created
between the private sector and the Federal Government. The in-
dustry, due in large part to its marketing efforts, now has greater
market penetration in earthquake insurance than ever before in
the history of the country, but the industry is alarmed that as its
penetration increases, reserves to meet its financial obligations
become increasingly inadequate.
So the question has shifted now from one of availability, which
in 1971 and 1981 studies and can be answered now in the affirma-
tive, to questions of market penetration and industry capacity.
Most in the industry now believe that future market penetration
will impair its ability to meet obligations in the event of a cata-
strophic earthquake, while on the other hand, a failure to provide
broader protection could leave hundreds of thousands of people un-
protected. Compounding the problem is the fact that courts are
now interpreting policy language in much broader terms than
either actuaries or underwriters had ever intended, and earth-
quake insurance is now required to be offered to all homeowners
and residential policies in the State of California.
Finally, I should point out that current Federal measures are not
adequate to assist the public with losses not covered by insurance.
Additional disaster assistance payments may not adequately com-
pensate victims and could at the same time create an extensive
and unnecessary drain of Federal funds.
On the other hand, a realistic insurance approach has several ad-
vantages over disaster assistance payments. First, insurance with
reasonably accurate rates could create a financial incentive for
property owners to minimize the risk. Second, insurance provides
more certain reparation than relief measures currently do. And
third, insurance allows each property owner to purchase the pre-
cise level of insurance protection he would desire.
Unfortunately, however, current proposals to deal with the in-
surance and earthquake question are either unacceptable to vari-
ous segments of the insurance industry or involve an unnecessary
increase of Federal intrusion into this area.
As Administrator, I have encouraged the industry to review the
proposals that are being circulated, and hopefully to draw positive
conclusions from each of them. Hopefully they would be able to
construct a solution to meet the needs of the public and to utilize,
to the extent possible, the private delivery mechanism.
To date, there are about three proposals being circulated within
the industry that are designed to meet this crisis. One of them is
Federal reinsurance. Another one would be a Federal reinsurance
corporation. And the third proposal is revisions to the Federal Dis-
aster Assistance Program.
I would like to take each of these and just briefly describe how
they would operate as the proposals are currently being circulated.
Federal reinsurance would act very similar to the original Riot
Reinsurance Program. It would provide financial backup in the
event of a catastrophic loss, but it would also include extensive
Federal oversight of the reinsurance mechanism. Another major
problem with creating simply a Government reinsurance program
is that it would have the effect of supplanting the private reinsur-
ance market which could, which would want to, and which could be
expected to play a significant role in any earthquake insurance
It is largely because of that latter reason that the Federal Rein-
surance Corp. concept has been presented within the industry,
largely being supported by the reinsurance industry. Under this
proposal, the government would create a Federal Reinsurance Cor-
poration which would be tax-exempt, federally charge, quasi-public
corporation to provide excess reinsurance for earthquake catastro-
phes. The corporation would have authority to borrow from the
Federal Treasury, but under the proposal, a primary layer from
the private reinsurance market would have to first be purchased
before anybody could purchase a second layer of coverage from the
Federal Reinsurance Corporation.
This proposal, like many of the others, still has some significant
problems that need to be worked out. For example, how would in-
surers be encouraged to participate to the maximum extent possi-
ble under the program? What criteria and qualifications should be
placed on foreign reinsurers to prevent primary insurers from pur-
chasing underrated reinsurance which potentially could prove in-
adequate, only so that they could become eligible for the Federal
program? What would the relationship be between a Federal earth-
quake catastrophe reinsurance corporation and other government
insurance or disaster relief programs? And finally, would the rein-
surance be limited to property damage or include other coverages
The final proposal that is currently being circulated in the indus-
try is one which divides earthquakes between a class 1 and class 2.
Under the scenario, a class 1 earthquake is one which would be
within the financial capacity of the insurance industry to meet. A
class 2 earthquake would be of such magnitude that the losses and
damage to privately insured property would be in the many bil-
lions of dollars and would be outside the scope that the private in-
surance industry could be expected to pay damages.
Under the proposal, the dollar threshold could change signifi-
cantly as the industry developed more surplus and reserves to meet
The major objection to this kind of approach is that it would dra-
matically change the current disaster relief program from one of
first dollar payments to one of more catastrophic types of coverages
after the insurance industry had met as many of the obligations as
they were financially able to meet.
I believe that many of these proposals could be amended to meet
the objections of the conflicting constituencies. What I have noted,
frankly, is a lack of such a commitment. We need an industry-wide
commitment to consolidate the favorable aspects from each of these
proposals. In my view, several expressed and implicit themes from
each of the proposals should form the basis of an industry-wide dis-
First of all, many perils which were once deemed uninsurable,
namely, wind damage, homeowners coverages and health insur-
ance, are now clearly insured by the private sector. The industry in
my view should review liberally the extent of the coverage they
could provide before calling upon any kind of Federal assistance to
Second, to encourage participation in this type of program, disas-
ter assistance should not be made available where private insur-
ance is. The prospect of a disaster declaration with readily avail-
able Federal grants and loans would make efforts to sell earth-
quake insurance more difficult.
Third, participation in any insurance program should be volun-
tary. This does not preclude private market incentives, but the
right of the individual to refuse the purchase and to bear the loss
alone must be respected. Fourth, program development should in-
clude a risk bearing and administrative role not only for the pri-
mary insurance market but for the reinsurance market as well.
Failure to incorporate all segments of the private insurance indus-
try would be a failure to use their resources adequately and wisely.
And finally, any proposal to deal with this problem should be de-
veloped by the private sector and then presented to the administra-
tion and to the Congress for review.
As I stated at the beginning of my testimony, these thoughts
really represent only my personal observations on this topic. We
have not had time really to review it in detail with the administra-
tion, but I could commit to this committee that if a legislative pro-
posal is developed along the lines that I have just outlined, I would
be happy to present it to the administration for its review.
In the meantime, Mr. Chairman, I am available to work with you
and this committee and the insurance industry on this difficult but
Senator GORTON. Thank you, Mr. Bragg.
Mr. HABER. Thank you, Mr. Chairman, for the opportunity to
speak here today.
In the 1970's under the auspices of the National Science Founda-
tion we conducted a study of the nationwide loss potential from a
number of different natural hazards. We examined the catastroph-
ic loss potential for a repeat of the great San Francisco earthquake;
we evaluated the loss potential for a repeat of the New Madrid
earthquake; and we estimated the local average annual loss poten-
tial due to earthquake throughout the Nation.
Upon review of those figures, it is interesting to compare them
with some of the testimony we have heard earlier today. We pro-
jected the loss due to a repeat of the great San Francisco earth-
quake, if it were to occur in 1985, to be approximately $16 billion.
Our estimates of the losses from a repeat of the New Madrid earth-
quake had a large uncertainty. The lower bound to our estimate of
building damage was $4 billion. The great uncertainty in this
region of the soil effects on strong motion amplification and attenu-
ation could make the losses as much as eight times larger. This re-
sults from the size of the area that could be affected and the mag-
nitude of the effects. Considering the greater magnitude now as-
cribed to a New Madrid earthquake, the building loss estimates are
comparable to the numbers that we have heard today.
The State of Washington had the distinction of the highest
annual per capita earthquake loss potential of any State in the
We certainly cannot predict when a great earthquake is going to
occur, but we can examine some of its potential consequences to
our Nation's financial institutions. There are many types of insur-
ance other than earthquake insurance against which claims are
likely to be made. For example, if I am in my office and an earth-
quake occurs damaging that building so that a beam falls injuring
my back, I would have a claim against my employer's workers'
compensation policy. In fact, it turns out-at least for one sample
study we performed for a client-that this type of loss may be as
great or greater than the building damage.
If I have an automobile that is damaged by that earthquake, I
may file a claim against my automobile insurance carrier, or if it is
damaged by a collapsing building, I may file a claim against the
building owner for third party liability.
Earthquakes may cause dams to fail, which in turn may cause
flooding, ensuing casualties, and further building damage. Addi-
tionally, pipeline failures may occur causing the release of toxic or
combustible gases. Electric powerline failures may cause the fail-
ure of life support systems and other critical facilities. An immedi-
ate example of this is Mexico City where hospitals collapsed. Com-
puter facilities process control, chemical processes may be disrupt-
ed. All of these incidients may cause significant damage beyond the
direct earthquake damage.
The failure of the property owner to preclude this type of
damage or to mitigate against it may be held as a reason for a
third party liability suit, and thus, third party liability insurance
may become a very significant portion of the claims.
Let's take a look at the current availability of earthquake insur-
ance. As my copanelist mentioned, the State of California has man-
dated that companies offering homeowners insurance offer an
option to the homeowners to buy earthquake insurance. This is
available, but it is available with a deductible equal to the probable
maximum loss. For a typical California home, even in the event of
a disaster, the homeowner does not obtain protection from his
earthquake insurance policy.
In the commercial market, the availability of earthquake insur-
ance has been reduced. Moreover, the limits of liability for policies
that are available have been drastically reduced. Premiums have
been escalated tremendously, and deductibles have been increased.
The consequences of this restricted availability of converage is not
limited to just these individual companies seeking protection but
has regional and national implications.
At the end of 1983, which is the last time in which data was
available from the California insurance commissioner, a cata-
strophic earthquake in the Los Angeles area would have resulted
in approximately $4.7 billion worth of claims. That dollar figure is
comparable to the daily trading volume on our Nation's securities
exchanges. Thus, in the event of such a disaster we could expect a
significant disruption of our national financial markets as the in-
surance companies proceeded to liquidate the assets necessary in
order to pay off those claims.
* This is likely to depress security prices and cause further diver-
sion of investment from the normal economic activity of our
Nation into the recovery operation.
A further consequence is the potential for mortgage default. Par-
ticularly in the absence of adequate earthquake insurance or in the
absence of the possibility of rapid response on the part of the Fed-
eral Government, the destruction of property and the interruption
of business reduces the capability of individuals and small business-
es to honor their payments to loan holders. This increases the pos-
sibility of a mortgage default, since the property itself forms the
collateral. The advent of a large number of small regional banks
who concentrate their loan activities within small geographical re-
gions increases the likelihood of bank failures.
This is further complicated by the dependence of banks on elec-
tronic data processing for transaction processing and recordkeep-
ing. Formerly, transaction were slower and written records were
used with ample backup records. Increasingly, we depend on com-
puters to manage transactions and recordkeeping. While large in-
stitutions are developing backup offsite computer facilities at
remote locations, small institutions cannot presently afford to take
these steps. Thus, at the time when these small institutions will
have their resources stretched to the maximum, their ability to
manage their business will be further hampered by the lack of ade-
Those are the major points I wish to make.
[The statement follows:]
STATEMENT OF JERRY HABER, NATIONAL TECHNICAL SYSTEMS
EARTHQUAKES, INSURERS AND SELECTED FINANCIAL INSTITUTIONS
Three major points will be' presented with regard to the insurance/financial in-
dustry and earthquakes:
1. An individual attempting to protect his home or business against earthquake
losses will find adequate coverage difficult to obtain and expensive in today's
2. If a great earthquake were to occur today a significant number of the claims
recieved by insurance companies might derive from policies not designed to cover
3. The impact of a great earthquake on financial institutions will not be confined
to insurance companies. The banking system will be affected by the destruction of
property securing loans. Insurance company liquidations of holdings in the financial
markets to satisfy claims will have a major impact on these markets.
Today the insurance industry is in the retrenchment portion of the underwriting
cycle. Even prior to the Mexican earthquake, as a consequence of large underwrit-
ing losses, reduced investment profits and years of low premium levels the insur-
ance industry has a significantly reduced underwriting capacity. The heavy losses
have been aggravated by the litigious nature of our society. Foreign reinsurers have
paid claims in the United States disproportionately high to the premium income
they were deriving in this country; moreover, many domestic reinsurers have suf-
fered severe losses. The result is that the primary (direct) insurance underwriters
have significantly reduced underwriting capacity and that they must ask higher
premiums for the coverage which they do offer. The claims from the Mexican earth-
quake will further reduce the capacity in the reinsurance market.
Although these factors apply across all lines of insurance, the effects are particu-
larly dramatic for those lines characterized by low probability, high magnitude
losses, such as product liability, professional liability and earthquake insurance.
Some companies are unwilling to write earthquake insurance. Those who are will-
ing to do so demand highly restrictive terms.
Coverage for commercial property has been available only with drastically re-
duced limits of liability. Rates and deductibles have risen. In California, earthquake
insurance for dwellings has a limited availability. The typical policy deductible is
set at ten percent of the value of the coverage. Coverage is typically available for a
minimum limit of liability of $100,000. This coverage is frequently available only to
purchasers of homeowner's policies.
This type of coverage has limited value to the homeowner. Much of the construc-
tion in this area is wood frame or wood frame with stucco. The Probable Maximum
Loss (PML) for this class of structure when built on rock or firm natural ground is
judged by industry to be 10 percent (As a point of reference, the mean damage level
for wood frame residential structures affected by the 1971 San Fernando Valley
earthquake was 5 percent). Thus, because the typical deductible is set at the PML
level these policies have minimal value. Furthermore, since the median value of im-
provements for a single family dwelling is less than $100,000, the majority of Cali-
fornia homeowners do not achieve any protection by buying this type of policy. The
policy is of some value to homeowners who own dwellings of poorer construction
(e.g., with cripple wall studs or unreinforced masonry walls) or dwellings not located
on competent soil.
Since 1978 the California Department of Insurance has required insurers to report
their aggregate liability incurred by writing earthquake insurance and their esti-
mated Probable Maximum Losses (PML). This reporting was established in order to
assure the public that the insurance industry would have adequate reserves to satis-
fy claims resulting from a great earthquake. In order to begin to assess the magni-
tude of the problem, the Department of Insurance made a number of compromises.
The complexities of the underwriting of large commercial accounts are not reflected
in the Department's methodology. Moreover, all structures of a given type were as-
sumed equally vulnerable to earthquake damage regardless of their actual proximi-
ty to fault zones or type of soil on which they were constructed. Finally, rather than
requiring independent audits, as are required for financial statements, the insurers
report their own liabilities. The Department of Insurance did, however, make the
provision that alternative methods of reporting might be proposed to the Depart-
ment. National Technical Systems (NTS) developed a method of simulating an
earthquake and estimating the resulting losses and their impact on an insurer's
portfolio. This method was approved by the Department of Insurance in 1979. Since
that time, we are one of two independent organizations approved by the State of
California to perform these analysis.
Even though the actions taken by the State of California, Department of Insur-
ance were an important step in mapping the liabilities of the insurance industry in
the event of a great earthquake, it is important to recognize that it is only a first
step. California is only one of several states that could be affected by a great earth-
quake. Earthquake insurance is only one of several lines of insurance under which
claims may be filed in the event of an earthquake. Although, at this time a thor-
ough evaluation of the magnitude of the claims that would arise under other lines
of insurance has not been made, the dollar value of claims from the non-earthquake
policies could be significantly greater than the claims under earthquake policies.
An initial indication of the magnitude of this problem was obtained by an earth-
quake Probable Maximum Loss (PML) study for workers compensation claims per-
formed by NTS for one of its clients for whom a previous analysis had been per-
formed of earthquake policy PML. Some of the other lines of insurance that may be
affected include life insurance, medical insurance, automobile insurance and third
party liability insurance. (While elimination of the doctrine of concurrent causation
in California reduced the number of types of insurance under which earthquake
damage claims may be filed there, the courts in other states may not have ruled on
the doctrine of concurrent causation. Thus, outside of California there may be, for
example, claims under a standard homeowner's policy. Moreover, claims under the
listed lines of insurance might occur in California or elsewhere.)
Third-party liability claims could be a contender for the major source of claims in
the wake of a great earthquake. An earthquake produces three types of damaging
effects: shaking, ground failure and water waves (seiches or tsunamis). These in
turn damage real estate, improvements and other manmade objects in the area.
Damaged structures may cause death or injury to their occupants. The damage
interferes with an occupant's ability to conduct his business and may, given a suffi-
ciently long interruption, put him out of business. Dam failures caused by earth-
quakes may cause extensive flooding and consequent casualties and property loss.
Direct damage to utility or industrial pipelines may release combustible or toxic
gases creating the hazards of fire or poisoning. Loss of electric power may damage
life support systems. Damage to hospitals, process control computers and data proc-
essing centers may have life threatening or, at least, severe economic consequences.
An argument may be made that the owner of the damaged property is liable for
these effects, for failing to preclude or mitigate their consequences.
The most recent (end of 1983) publicly available estimate from the California De-
partment of Insurance of insured losses from a great earthquake in the Los Angeles
area is $4.66 billion. Even if this represented all lines of insurance under which
claims would be made (and as discussed earlier it is only a fraction of the total),
$4.66 billion is comparable to the daily dollar volume of trading on the country's
major financial markets. Thus, the need for massive liquidations of securities and
other investments in the weeks and months following the disastrous event might
disrupt orderly trading on these markets, depress the average value of assets held
both by the insurance industry and others and result in further massive diversion of
capital from normal investment opportunities to recovery and repair activities.
The final major threat to the financial stability of major institutions comes from
potentially high rates of mortgage defaults in areas severely affected by earth-
quakes and the further possible failures of marginally viable banks or savings and
loan institutions. When a dwelling or business sustains severe damage in an earth-
quake, if the owner's personal resources, insurance or disaster relief is not fully ade-
quate to meet restoration/recovery needs the owner may not be able to engage in
necessary property repairs. This may force the mortgages into default. The likeli-
hood of default may be increased by business interruption losses and the accompa-
nying temporary or permanent unemployment. Since the property is the lender's
collateral, if the damaged property's value is less than the outstanding balance a
loss will be incurred by the lender. Small savings and loans and banks are especial-
ly vulnerable to these losses because they tend to concentrate their loans within a
small geographical area. Moreover, with the advent of electronic banking financial
institutions now depend heavily on computer systems. While the larger institutions
are developing geographically dispersed backup systems to allow them to continue
functioning in the event of an earthquake the smaller institutions are less capable
of providing this backup capability. Thus, they may face the potential threat of loss
of records and resulting confusion at a time that they most need their records to
manage their uncertain loan portfolio and to control withdrawals of deposits.
Management of these problems requires (1) addressing the insurance industry's
capacity problem, (2) a more complete definition of the earthquake induced losses
that insurers may face in lines of insurance other than earthquake insurance, (3) an
assessment of the earthquake induced mortgage default problem, (4) development of
effective backup computer capacity for the financial industry and (5) development of
an orderly procedure for insurance companies to liquidate securities after a massive
disaster so that there is no "run on the market".
[The following information was subsequently received for the
QUESTIONS OF SENATOR GORTON AND THE ANSWERS
Question 1. You have outlined in your testimony rather significant problems re-
lated to: the availability of earthquake insurance; the exposure of insurance compa-
nies to claims resulting from a catastrophic earthquake; the effect of such an earth-
quake on other financial institutions.
In your opinion, what options should be considered for a federal role in helping to
mitigate these effects:
Answer. There are several important roles the Federal government must take to
mitigate these effects. Definitions of the optimum long term solution is a complex
problem which requires a benefit/risk analysis of individual options and sets of op-
tions to all affected parties. A follow-on investigation to our 1981 study for the Fed-
eral Insurance Administration should be initiated to provide Congress with these
long term guidelines. Because of the catastrophic loss potential should a great earth-
quake occur in the meantime, we cannot afford to wait for a definition of the opti-
mum policy. Thus, although definition of the optimum policy will require an exten-
sion to our study, I will define some interim solutions that Congress can enact now.
The single most effective role the Federal government can play is to foster loss
control mitigations. A reduction in the catastrophic loss potential protects the
public, reduces the need for earthquake insurance, reduces the expected value of in-
surance claims, reduces the likelihood of loan defaults, and reduces the impact of
claims handling on the nations securities markets. It has been estimated that an
effective mitigation program could reduce losses by 25 to 50 percent. (In terms of the
building losses for a~ repeat of the great San Francisco earthquake that would
amount to more than $4 billion savings.)
I believe that an effective incentive can be provided to property owners through a
combination of low-interest loans (priced at the government's cost of money plus
transaction costs) plus tax credits. This combination of incentives would foster seis-
mic retrofit without discriminating against "cash-poor" individuals. The only costs
to the government would be the foregone revenues resulting from the tax credits.
Even this cost is more apparent than real. Implementation of the retrofit program
would employ people, promoting the local economy and enhancing the Federal tax
In order to facilitate indentification of effective mitigations and to minimize abuse
of this program a simple set of guidelines should be developed to identify earth-
quake mitigations which may be certified as effective by building inspectors. This
should be supplemented by a procedure to allow a registered professional define al-
ternative effective mitigations.
A second step the Federal government can take is to promulgate interim regula-
tions for lending institutions to minimize the impact of catastrophe-induced loan de-
faults. The key to these new regulations is the dollar loss each institution can sus-
tain without posing a serious risk to its financial stability. Each institution would be
required to demostrate that it has an earthquake disaster preparedness plan to
assure its financial integrity. Provisions of the plan would include preventative
measures and remedial strategies. Candidate remedial strategies might include
mortgage default insurance (covering earthquake) or a hazard induced loss sharing
pool with other geographically dispersed lending institutions. One preventative
measure is to require borrowers to establish that their residual equity is greater
than the probable maximum loss that an earthquake will cause. Another measure
would be for the lending institution to establish that its loan portfolio had an ade-
quate geographical spread to preclude its financial demise in the event of a great
The Federal government will, in one way or another, be the insurer of last resort.
It will either develop an effective partnership with the insurance industry to assure
the public adequate protection through earthquake insurance and the insurance in-
dustry adequate reserves to settle claims, or it will face the burden of funding post-
disaster relief and reconstruction to the afflicted communities. The issues associated
with the optimal Federal role are complex and a definition of that policy should use
-our---1~98-1---study---and subsequent research funded by the Federal govenment as a
point of departure.
Presently, I believe that an effective element for assuring insurance companies an
adequate spread as part of that Federal role is the development of natural hazards
insurance and promulgating appropriate regulations to assure its widespread sale
throughout the country. A natural hazards policy (or endorsement) would provide
protection against wind (hurricane, tornado, and severe winds), water (riverine
flooding, storm surge, and tsunami) and earth (earthquake, expansive soil, and land-
slides) hazards. Their use of a geographically diversified all-natural hazard policy
would significantly broaden the underwriting base and provide a mechanism for
"smoothing" the annual variation in claims costs. It is anticipated that natural haz-
ards' insurance would attract a significantly broader policy holders' base than
earthquake insurance alone does. Ultimately, I believe this broader market would
alleviate much of the earthquake insurance related capacity problem faced by the
insurance industry. The optimum combination of this and other possible solutions
must await a conclusion to an extension of our 1981 study.
Question 2. Associated with your company is Dr. John Wiggins who in 1981 com-
pleted a study requested by the Federal Insurance Administration, on options open
to the federal government for involvement in an earthquake insurance program.
Have major changes occurred since 1981 that we should consider when reading this
study? Are there areas of study that should be conducted as logical follow-ups, or
extensions of, the "Wiggins Report"?
Answer. In our 1981 study for the Federal Insurance Administration a number of
policy problems related to eathquake insurance were identified. Candidate Federal
roles were identified in that study including fostering development and implementa-
tion of earthquake loss mitigation measures; acting as a reinsurer of last resort or
providing "catastrophe" loans to insurers; and requiring recipients of federally-
backed loans to purchase earthquake insurance. The study workshop participants
ranked the candidate Federal roles based on their subjective assessments of effec-
tiveness in solving the policy problems. It is not surprising that workshop partici-
pants rated loss mitigation meaures as the single most important Federal role. Ef-
fective loss control significantly reduces the magnitude of losses which would result
from a catastrophe. Nevertheless, implementation of loss control measures will take
time and will be met with a certain amount of resistance from those who must bear
the costs of the mitigation efforts. Consequently, other supplemental measures must
be implemented to provide protection to property owners and to insure the viability
of our nation's financial institutions. Some of these were identified in our 1981
study. A follow-up study should be conducted which defines the benefits and risks to
the various stakeholder groups of various federal roles and policies.
It is important that the study be broad enough in scope to address all lines of
insurance which may be significantly affected by an earthquake (for example, auto,
inland marine, mortgage default, third party liability) and all stakeholders in the
decision process. The costs, benefits and roles that will be required of Federal, state
and local agencies must be addressed. But before these governmental roles can be
defined, the defacto losses which would be sustained by different segments of the
economy from possible great earthquakes throughout the country must be assessed.
Our company, U.S.G.S., the National Science Foundation and FEMA have previous-
ly performed important segments of this loss assessment. These studies should be
reviewed in conjunction with ongoing research funded by these agencies. It should
be updated and supplemented as necessary to provide a basis for the analysis. While
a complete and ongoing assessment of the relationship of losses to governmental
roles is important to assure the effectiveness of these mitigation programs, it must
not be allowed to unduely delay the initiation of effective action.
The study should include an evaluation of the opportunities and restrictions pro-
posed policies impose on land owners, insurance companies, banks and the securities
markets. It should address the time phasing of the implementation of alternative
options. While abrupt institutional changes can cause disruption of the smooth func-
tioning of governmental and private institutions, delay in the implementation of
necessary mitigations increases the risk of a catastrophic earthquake in the interim.
This would not only affect the property owners suffering damage but would contrib-
ute to the national deficit and attack the GNP.
Senator GORTON. Thank you all very much. We appreciate your
testimony on a particularly difficult aspect of this issue. We do
have a number of questions for each of you, but in light of the
hour, we are not going to ask them now. We will submit them to
each of you in writing and hope that you will enlighten us by an-
swering them in writing for us for the record.
Thank you very much.
We are adjourned.
[Whereupon, at 1:30 p.m., the subcommittee recessed subject to
the call of the Chair.]