Earthquake Hazard

1
Earthquake Hazard A Primer by Muawia Barazangi
and Christopher Harig Institute for the Study of
the Continents Snee Hall Cornell
University Ithaca, New York 14853 (July 30, 2004)
The following pages/slides describe
comprehensive guidelines to address all issues
related to an Earthquake Hazard program. These
guidelines are designed to be relatively simple,
but also accurate and complete. Initially we
searched both printed references and Internet
sites looking for such a complete document, but
without any success. Of course, we did find
numerous documents and publications that discuss
different aspects of earthquake hazard. We have
extensively used different elements from these
available publications while developing our own
system (see references at the end of this
document). This document represents an
earthquake hazard framework that we have
developed that makes use of abundant available
literature and is time-based. That is, we
discuss the different components of an earthquake
hazard program based on how far or close a
particular component is from the origin time of
an earthquake. Needless to say, this document
will be revised and updated as we receive
comments and suggestions from the readers.
Please send your comments and suggestions to
Muawia Barazangi (mb44_at_cornell.edu)
2
Earthquake Hazard in SyriaAssessment
1. Tectonic/geologic framework of Syria 2. Why
earthquakes in Syria 3. Active faults in Syria 4.
Earthquake distribution, both recent and
historical 5. Surface deformation, movement, and
shaking during an earthquake 6. A possible
tsunami along coastal Syria 7. Local geology and
earthquake intensity 8. Likely effects of a major
earthquake on engineering structures and
subsurface life-line infrastructures 9. What to do
3
Earthquake Hazard

• Assessment (Geological/Geophysical Basic Studies,
  
• Engineering aspects, Site Characteristics,
  Sociology and
• Human Relations)
• Preparedness (Time Based Scale)
• During Earthquake (Short Phenomenon)
• Response (Time Based Scale)
• Recovery (Months, Years)

4
Earthquake Hazard

• Assessment
• Seismology Networks (seismic/strong motion),
  seismicity, focal mechanisms, attenuation,
  reflection refraction, crust upper mantle
  structure, tomography, modeling, historical
  earthquakes, paleoseismology, etc.
• Geophysics GPS, InSAR, gravity/magnetics, GPR,
  Remote sensing, etc.
• Active Tectonics Field structural geology,
  trenching, geomorphology, mapping of
  faults/folds/basins, Quaternary and Recent
  dating, imagery, etc.
• Engineering Aspects Engineering seismology,
  earthquake engineering, site characteristics
  (soil and bedrock), shallow drilling, structural
  engineering, testing shaking, modeling, etc.
• Sociology and Human Relations
• Earthquake Economy and Insurance

5
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Medium Term Planning (Months)
• Imminent Planning

6
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Individual/Family
• Community/State

7
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Individual/Family
• Land Use (finding safe places to live/build)
• Home Safety
• Workplace Safety

8
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Individual/Family
• Land Use (finding safe places to live/build)
  While land use may seem like a State
  responsibility, there is much an individual can
  do. People can examine the environment and
  decide not to live in areas with greater natural
  hazard. Choosing to live in one area of
  Damascus, for example, versus another could have
  a great impact during the next earthquake. After
  being educated about the hazard and risks,
  individuals are able to make better informed
  choices about where to live.http//www.seismic.c
  a.gov/celrp/sscland.htm http//www.pnsn.org/INFO
  _GENERAL/NQT/reduce_losses.html

9
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Individual/Family
• Land Use (finding safe places to live/build)
• Home safetyFamilies are the best equipped to
  determine hazard risk in their home. If they are
  involved in the construction of a new home,
  homeowners should take on the responsibility of
  making sure their construction follows proper
  seismic building codes. Alternatively, families
  should examine their current home and determine
  whether it is secure enough for the hazard. This
  process varies with locale and building methods.
  Also, all homeowners living in an earthquake
  hazard area should invest in earthquake
  insurance. While saving lives is the first
  priority, the financial cost of an earthquake
  disaster is also very significant and sometimes
  overlooked.

10
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Individual/Family
• Land Use (finding safe places to live/build)
• Home safety
• Workplace SafetyIt is both the responsibility of
  the individual and the State to estimate and/or
  determine the relative safety of the workplace.

11
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Individual/Family
• Community/State
• Land Use (finding safe places to live/build)
• New Construction
• Current Structures
• Response Infrastructure
• Public Education

12
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Community/State
• Land Use (finding safe places to live/build)As
  the population in seismic hazard areas continues
  to grow, so does the risk of loss from
  earthquakes. Land use consideration is one of
  the simplest things the government can do to
  prevent earthquake losses. There are several
  important things that need to be considered when
  planning for land use area seismic hazards
  should be sufficiently mapped (microzonation),
  geologic hazard reports should be created for new
  development areas, local/regional hazard
  information needs to be directly addressed in all
  site use planning, emergency response to areas of
  increased hazard should be considered, and cost
  and speed of recovery should also be considered.
  Though it is not possible to move mega-cities
  (such as Damascus), it is quite possible to
  significantly improve the safety of most
  infrastructures of such cities.

13
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Community/State
• New ConstructionIn this instance the State is
  in a unique position to greatly impact the safety
  of many people with a reasonable increase in the
  cost. The development of seismic building codes
  and enforcing their use in construction of new
  private homes, utilities such as power lines, and
  State buildings such as hospitals and schools
  have the potential to save many lives and prevent
  financial losses in a disaster.

14
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Community/State
• Current StructuresAs part of developing a
  seismically prepared urban environment, existing
  structures are also in need of attention. The
  State should study the sustainability and
  retrofit of existing structures such as schools,
  hospitals, and lifelines. Retrofitting is a cost
  effective method of earthquake risk mitigation.
  The government should also encourage private
  building owners to upgrade and retrofit their
  structures with incentives such as tax
  breaks.http//www.seismic.ca.gov/sscmit.htm

15
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Community/State
• Response InfrastructureIn addition to risk
  mitigation, a key goal of the State should be
  preparing for response in the event of a
  disaster. At the national level, the state can
  assist local governments in the development of
  response infrastructure such as fire and police
  departments, and urban search and rescue units.
  They can also provide support for all existing
  departments through national agencies. These
  agencies (such as Fire Administration) can aid in
  the purchase and maintenance of equipment used in
  response and recovery operations. In addition,
  it is imperative that the State develop
  telecommunications at both local and national
  levels.http//www.usfa.fema.govhttp//www.fema.
  gov/usr

16
Earthquake Hazard

• Preparedness (Time Scale Based)
• Long Term Planning (Years)
• Community/State
• Public EducationIt is essential that the
  population is aware of and understands the basics
  of earthquake hazards Schools and the media
  should be the focus of this education effort.

17
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Individual/Family
• Community/State

18
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Individual/Family
• Family Emergency Planning Since emergency
  personnel cannot help everyone immediately, it is
  important for families to make their own
  emergency plan of action after a disaster. The
  plans can help families stay organized in times
  of crisis, and can help families to help
  themselves. These plans can vary in detail, but
  they should all touch upon the following topics
  arrange meeting locations for family members
  after a disaster, set up a family contact outside
  of your region to coordinate communication
  between family members, discuss different actions
  that are needed for different disasters, and
  discuss the possibility of an evacuation.http//
  www.redcross.org/services/disaster/0,1082,0_601_,0
  0.html

19
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Individual/Family
• Community/State
• Disaster Response/Recovery Planning
• Public Education
• Maintaining Readiness/Response Capabilities
• Communications

20
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Community/State
• Disaster Response/Recovery Planning Disaster
  response planning is a key aspect of
  preparedness. It is important that those
  involved with the response have defined tasks and
  those in charge of response and relief management
  have clearly defined responsibilities. For
  example, before the 1906 San Francisco earthquake
  the city had one of the best systems of fire
  departments in the world, but fires burned in the
  city for over 3 days, due partly to poor
  planning. Examples of response plans at the
  State and local level include the U.S. Federal
  Response Plan and the California Emergency Plan.
  www.fema.gov/rrr/frpwww.oes.ca.gov/OEShomeP.nsf
  /All/CAEmergencyPlan/file/CEP.pdf

21
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Community/State
• Disaster Response/Recovery Planning Continued
  Governments should develop response plans that
  coordinate disaster response between various
  government agencies and delegate responsibility
  of response tasks. It is also important that the
  public have confidence in the preparedness for
  disasters and management of response. This can
  be aided by the governments show of support for
  those in charge of these areas. Recovery plans
  can also be very useful in the wake of a
  disaster. Disasters such as earthquakes provide
  opportunities for redevelopment of damaged areas,
  relocation of neighborhoods to safer sites, and
  upgrading of structures, such as bridges, that
  were damaged. The State should develop flexible
  recovery plans which can be tailored to the
  specific damage caused by a disaster.

22
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Community/State
• Public Education A good way to encourage public
  preparedness for a disaster is for the public to
  be educated about the danger they face and about
  what they can do themselves in terms of
  preparedness and response. This education can be
  incorporated into general science curriculum in
  schools. To educate those not in schools, a
  public awareness campaign should be undertaken.
  The government can take advantage of public
  transportation advertisements and public service
  announcements on the radio, television, and in
  newspapers. The government should organize
  civilian practice drills. Similar to response
  drills involving police, firefighters, etc., they
  will help keep the public attentive to the danger
  of earthquakes.

23
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Community/State
• Maintaining Readiness/Response Capabilities To
  assure that response authorities are prepared to
  respond to some of the unique challenges that an
  earthquake disaster may present, full response
  practice drills should be performed regularly.
  These drills will help determine the current
  state of readiness and response capabilities and
  determine what areas have the most room for
  improvement. They will help prevent any
  deterioration in readiness and response
  capabilities as well. To provide the most
  benefit, the drills should attempt to accurately
  recreate what will be experienced after an
  earthquake and include activities of
  firefighters, police, urban search and rescue
  units, emergency medical response teams, and
  other personnel.

24
Earthquake Hazard

• Preparedness (Time Scale Based)
• Medium Term Planning (Months)
• Community/State
• Communications While communications
  infrastructure is commonly a private sector
  responsibility, it is imperative that response
  authorities have access to communications after a
  natural disaster. In some instances this access
  must come at the expense of civilian access to
  traditional land line and wireless
  telecommunications. The government should assess
  its communications need and ability to make use
  of traditional land line, wireless, and radio
  communications when necessary. Then, through
  coordination with telecommunications companies,
  this information can help assure that government
  access can be maintained throughout the phases of
  a disaster.

25
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Individual/Family
• Community/State

26
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Individual/Family
• Emergency Supplies
• Family Education
• Preparing the Home

27
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Individual/Family
• Emergency Supplies An earthquake usually wreaks
  havoc on utilities such as electricity and
  natural gas as well as both municipal and natural
  artesian water supplies. Any disruption or
  difficulty not only affect families directly but
  can lead to secondary effects such as a
  disruption in food availability. Thus it is
  prudent to prepare for such events by storing an
  emergency supply of food and bottled water.
  These items are likely to become scarcer after an
  earthquake, when they are most needed. Families
  should store enough supplies for 3-4 days. By
  that time, if the shortage has not been
  eliminated, relief supplies should be available.

28
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Individual/Family
• Family Education As mentioned earlier, the
  government should undertake a public awareness
  campaign to help educate the public about the
  dangers and risks associated with earthquakes.
  In addition, informed individuals should assume
  responsibility for educating their family and
  friends about earthquakes. Each family member
  should know what to expect and what to do when an
  earthquake occurs. A simple way to prepare is to
  perform drills for what to do in the event of an
  earthquake both at home and at work. They should
  include actions such as taking shelter during an
  earthquake and what to do immediately afterward.

29
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Individual/Family
• Preparing the Home One of the most significant
  financial costs of an earthquake is from
  non-structural damage, most of which can be
  prevented. Individuals should inspect their home
  for potential hazards and manage them. Large
  objects such as dressers, light fixtures, and
  loose objects on shelves should all be secured to
  something solid such as a wall.

30
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Individual/Family
• Community/State
• Readiness
• Response Planning

31
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Community/State
• Readiness There should be a continual effort to
  organize earthquake awareness periods, including
  the media, and to organize citizen practice
  drills for duck, cover, and hold procedures. To
  maintain readiness the State must continually
  maintain and test response equipment and special
  communications system. The coastal regions,
  especially the major coastal cities, should be
  prepared for possible tsunami. A system for
  stand-by supplies of food, water, medicine, and
  temporary shelters should be organized. Also,
  the State should organize scientific and
  engineering teams to be ready. Finally, the
  State should establish a chain of command on all
  levels of decision making.

32
Earthquake Hazard

• Preparedness (Time Scale Based)
• Imminent Planning
• Community/State
• Response Planning The State should organize a
  procedure on how to turn off all utilities,
  industry, and transportation infrastructure.
  They should also establish contact with
  neighboring countries and international relief
  organizations to clarify the nature and amount of
  anticipated help and support.

33
Earthquake Hazard

• During Earthquake (Short Phenomenon)
• Red Cross http//www.redcross.org/services/disaste
  r/0,1082,0_583_,00.html
• FEMA http//www.fema.gov/hazards/earthquakes/equa
  kes.shtm

34
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Response from Weeks to Months

35
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Individual/Family
• Community/State

36
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Individual/Family
• Red Crosshttp//www.redcross.org/services/disaste
  r/0,1082,0_583_,00.html
• FEMAhttp//www.fema.gov/hazards/earthquakes/equak
  es.shtm

37
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Individual/Family
• Community/State
• Response Efforts
• Infrastructure Response
• Issues of People

38
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Response Efforts After a natural disaster,
  initial response activities sometimes suffer from
  a lack of organization and a lack of speed.
  Following response plans that have been developed
  will help to organize and bring efficiency to the
  response effort.Response activities of police,
  firefighters, urban search and rescue, etc.
  should be coordinated from a central location.
  This will allow them to be efficiently directed
  to where they are needed most.

39
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Response Efforts Continued As part of the
  response plan a communications center should be
  created. Its purpose would be to coordinate
  communications and disaster information sharing
  among response agencies and/or groups.Special
  attention and permits should be granted to
  scientific and engineering teams to inspect and
  study the affected areas.

40
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Response Efforts Continued The possibility of
  aftershocks can continue weeks after a large
  earthquake occurs. Response centers such as
  command headquarters, interim housing, temporary
  medical facilities, etc. should be chosen with
  this in mind. They should be located in areas
  away from the earthquake if possible to avoid
  additional damage.

41
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Infrastructure Response Hospitals and other
  municipal buildings such as schools and mosques
  will play an important role in response.
  However, before the hospitals begin to accept
  many earthquake injuries, or before shelters are
  established in schools and mosques, the safety of
  these vital buildings should be determined. They
  should be inspected for earthquake damage and
  whether they can survive an aftershock.

42
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Infrastructure Response Continued A strong
  earthquake will likely create disruptions in area
  lifelines, such as the power grid, natural gas
  supply, water supply, etc. Responsibility for
  these lifelines can vary between the State and
  private utility companies depending on region.
  However, both sides have a vested interest in
  restoring the lifelines to full capacity, and
  should work together to accomplish this quickly.

43
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Issues of People Earthquakes often destroy or
  damage many homes, creating many displaced
  persons. Shelters need to be organized to
  provide interim housing while their homes can be
  rebuilt. Additionally, their food and water
  needs must be provided for. An important
  development in disaster relief has been Mobile
  Hospital units. These nearly self-sufficient
  units are able to be deployed to disaster areas
  and supplement the capacity of the local medical
  facilities. There are certain guidelines to keep
  in mind when these units are involved. They will
  help get the most benefit out of the mobile
  hospital units.

44
Earthquake Hazard

• Response (Time Scale Based)
• Immediate Response
• Community/State
• Issues of People Continued After a disaster,
  relief supplies from humanitarian groups such as
  the Red Cross/Red Crescent will likely be
  available. Management of these supplies,
  including delivery, storage, distribution, etc.,
  should be coordinated with supplies that the
  government provides to ensure efficient use and
  avoid waste.The severity of injuries will vary
  depending on the magnitude of the earthquake. In
  the case of a large earthquake, nearby medical
  facilities will be inundated by minor injury
  patients. Seriously injured patients should be
  evacuated out of the disaster area to be treated
  at other medical facilities. There they can be
  better treated, and allow the nearby facilities
  to concentrate on the many more minor injuries.

45
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Individual/Family
• Community/State

46
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Individual/Family
• Personal Safety
• Home Safety

47
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Individual/Family
• Personal Safety It should be the responsibility
  of individuals to see that they receive medical
  attention for health problems related to the
  earthquake. This may seem like a simple task for
  those with health insurance, but for those
  without health insurance it can be difficult.
  Since an earthquake is a natural disaster that
  can impact everyone who lives in a region, the
  state should, if possible, provide free medical
  services to those injured.

48
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Individual/Family
• Home Safety It should also be the
  responsibility of families to make sure that
  their homes are safe to live in again. However
  the state should inform them about this
  responsibility and what is entailed in
  determining their home safety. This can be
  included in public information campaigns both
  before and after an earthquake occurs.

49
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Individual/Family
• Community/State
• Infrastructure
• Issues of People
• Transition to Recovery

50
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Community/State
• Infrastructure As time since the earthquake
  progresses, a detailed inspection should be done
  on buildings that have been affected. This
  should include all medium to large sized
  buildings. Inspection of residential houses is
  best left to the family that lives there. The
  inspections will determine whether the buildings
  are fit to be reoccupied.The government should
  inspect and, if necessary, rebuild all lifeline
  facilities and other infrastructures. The
  government should remember to remain vigilant
  about enforcing seismic construction/building
  codes and include them when rebuilding damaged
  infrastructures.

51
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Community/State
• Issues of PeopleAs mentioned earlier, the State
  should attempt to provide free medical services
  to anyone injured by an earthquake. This can
  include care for physical injuries as well as
  psychological problems associated with family
  deaths, loss of property or livelihood, etc.
  Often after an earthquake, displaced persons
  will decide to leave the region and live with
  relatives or friends until they can rebuild their
  lives in their former city. Alternatively, many
  people are forced to reside in disaster relief
  housing until they have somewhere to return to.
  Any assistance the government can provide in the
  relocation process, either out of the region or
  back to rebuilt homes will likely be well
  received. This can come in the form of
  transportation for both people and personal
  belongings.

52
Earthquake Hazard

• Response (Time Scale Based)
• Response from Weeks to Months
• Community/State
• Transition to Recovery Regardless of whether a
  redevelopment plan has been agreed upon, the
  government should make sure that buildings unable
  to be reoccupied are demolished. This benefits
  the general safety of the area residents. These
  buildings have the potential to collapse on their
  own under the right conditions, and thus present
  a new hazard to the nearby community. The
  government will also need to coordinate the
  removal of rubble and debris of collapsed
  structures.Hopefully the government had
  previously prepared a recovery plan in the event
  of an earthquake. Now, in light of current
  earthquake damage, it is advisable to make
  revisions to this plan so that it can address
  specific recovery items that now must be
  undertaken. The sooner that a region can
  complete its structural and infrastructural
  recovery, the sooner it will be able to complete
  its economic and cultural recovery.

53
Earthquake Hazard

• Recovery (Months to Years)
• Rebuilding
• Resettlement
• Assessment of Experience

54
Selected Web References

• USGS http//www.usgs.gov
• Hazards homepage http//www.usgs.gov/themes/hazard
  .html
• USGS Earthquakes http//earthquake.usgs.gov/
• FEMA http//www.fema.gov
• Earthquake Hazards http//www.fema.gov/hazards/ear
  thquakes/
• National Capability Building http//www.fema.gov/p
  reparedness/ncb.shtm
• Caltech Seismological Laboratory
  http//www.gps.caltech.edu/seismo/
• Southern California Earthquake Data Center
  http//www.data.scec.org/
• American Red Cross http//www.redcross.org/
• Disaster Services http//www.redcross.org/services
  /disaster/
• Earthquakes http//www.redcross.org/services/disas
  ter/0,1082,0_583_,00.html

55
Selected Web References

• California Seismic Safety Commission
  http//www.seismic.ca.gov/
• Mitigation Plan http//www.seismic.ca.gov/sscmit.h
  tm
• CA Governors Office of Emergency Services
• http//www.oes.ca.gov
• Earthquake Advisor http//www.earthquakeadvisor.co
  m
• Washington State Earthquake Hazards
• http//www.pnsn.org/INFO_GENERAL/NQT/welsome.html

56
Selected Web References

• International House, Osaka Japan
  http//www.ih-osaka.or.jp/i.house/index-e.html
• http//www.ih-osaka.or.jp/enjoy/en/emergency/index
  _en.html
• Geoscientific Research Institute
  http//www.gfz-potsdam.de/
• What to do if you experience an earthquake
  (mitigation perspective)
• http//www.gfz-potsdam.de/bib/pub/schule/earthquak
  es_0312.pdf
• UN Disaster Mitigation Training Programme
  http//www.undmtp.org
• Modules http//www.undmtp.org/modules_e.htm

57
Selected Print References

• U.S. Department of the Interior, U.S. Geological
  Survey, and Southern California Earthquake
  Center. Putting Down Roots in Earthquake Country
  p. 28, 1995
• U.S. Department of the Interior, U.S. Geological
  Survey. The Next Big Earthquake p. 22, 1990
• Pan American Health Organization. Disasters
  Preparedness and Mitigation in the Americas.
  Washington, D.C. Issue 94. p. 8. Jan 2004.
• U.S. Department of Housing and Urban Development,
  Office of Policy Development and Research.
  HUD-1511-PDR. Preparing for the Big One
  Saving lives through earthquake mitigation in Los
  Angeles, California. Washington, D.C. p. 52, 1995