4th Annual Disaster Medicine Symposium

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4th Annual Disaster Medicine Symposium
Earthquake
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Public Health Consequences of Earthquakes

• Charles E. Stewart MD EMDM MPH

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• A major earthquake affecting a large United
  States city has the potential to be the most
  catastrophic natural disaster ever seen in the
  USA.

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Frequency of Occurrence of Earthquakes
Descriptor Magnitude Average Annually
Great 8 and higher 1 ¹
Major 7 - 7.9 17 ²
Strong 6 - 6.9 134 ²
Moderate 5 - 5.9 1319 ²
Light 4 - 4.9 13,000(estimated)
Minor 3 - 3.9 130,000(estimated)
Very Minor 2 - 2.9 1,300,000(estimated)
¹ Based on observations since 1900. ² Based on observations since 1990. ¹ Based on observations since 1900. ² Based on observations since 1990. ¹ Based on observations since 1900. ² Based on observations since 1990.
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Scope/Relative Importance of Earthquake
Disasters

• During the past 20 years, earthquakes alone have
  caused more than a million deaths worldwide.
• Nine countries account for more than 80 of all
  fatalities this century, and almost half of the
  total number of earthquake deaths in the world
  during this period have occurred in just one
  country--China
• The United States has been lucky so far.
• Only an estimated 1,600 deaths have been
  attributed to earthquakes since colonial times,
  with over 60 of these having been recorded in
  California.

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Growing Risks

• Population growth in areas of high seismic risk
  in the United States has greatly increased the
  number of people at risk since the last
  earthquake of great magnitude struck (1906 in San
  Francisco).
• There are a LOT more people in Memphis than in
  1812
• Researchers estimate that a repetition of the
  1906 San Francisco earthquake, which measured 8.3
  on the Richter scale, could cause 2,000 to 6,000
  deaths, 6,000 to 20,000 serious injuries, and
  total economic losses exceeding 120 billion

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Growing Risks

• Earthquakes have even occurred on the east coast.
  
• Charleston, South Carolina, experienced a
  magnitude 6.8 (Intensity X) earthquake in 1886
  that killed 83 people and was felt over most of
  the United States east of the Mississippi River
• Washington DC earthquake (5.9 Richter) 23 August
  2011 had significant damage to many monuments
  including the Washington Monument.

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Factors that Contribute to Earthquake Disasters

• Depending on magnitude, proximity to an urban
  center, and the degree of earthquake disaster
  preparedness and mitigation measures implemented
  in the urban center, an earthquake can cause
  large numbers of casualties.
• The risk of catastrophic earthquakes in the
  western part of the United States is widely
  recognized
• Few people realize the high probability that a
  major earthquake will hit the eastern United
  States in the next several decades.
• Three great earthquakes (estimated magnitudes
  8.6, 8.4, and 8.7) all of intensity XII occurred
  during a 3-month period in the winter of
  1811-1812 near the town of New Madrid, Missouri.

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Trauma in an Earthquake

• Trauma caused by the collapse of buildings or
  falling pieces of the building is the cause of
  most deaths and injuries in most earthquake.
• Deaths resulting from major earthquakes can be
  instantaneous, rapid, or delayed.

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Injuries Causing Death
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Minor Injuries Following Earthquakes

• The majority of people requiring medical
  assistance following earthquakes have minor
  lacerations and contusions caused by falling
  elements like pieces of masonry, roof tiles, and
  timber beams.
• The next most frequent reason for seeking medical
  attention is simple fractures not requiring
  operative intervention.
• Such minor injuries usually require only
  outpatient-level treatment and tend to be much
  more common than severe injuries requiring
  hospitalization.

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Major Injuries Following Earthquakes

• Major injuries requiring hospitalization
• Skull fractures with intracranial hemorrhage
  (e.g., subdural hematoma)
• Cervical spine injuries with neurologic
  impairment
• Damage to intrathoracic, intra-abdominal, and
  intrapelvic organs such as pneumothorax, liver
  lacerations, and ruptured spleen
• Most seriously injured people will sustain
  combination injuries, such as pneumothorax in
  addition to an extremity fracture.

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Injuries Causing Death

• Instantaneous death
• Severe crushing injuries to the head or chest
• External or internal hemorrhage
• Drowning from earthquake-induced tidal waves
  (tsunamis).
• Rapid death occurs within minutes or hours
• Asphyxia from dust inhalation or chest
  compression
• hypovolemic shock
• environmental exposure (e.g., hypothermia)

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Injuries Causing Death

• Delayed death occurs within days
• Dehydration
• Hypothermia
• Hyperthermia
• Crush syndrome
• Wound infections
• Postoperative sepsis

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Injuries Causing Death

• Identified major medical complications causing
  frequent deaths in past earthquakes
• Crush syndrome
• Hypothermia
• Secondary wound infections
• Gangrene requiring amputation
• Sepsis
• Adult respiratory distress syndrome (ARDS)
• Multiple organ failure

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Other Problems

• A large number of patients require acute care for
  nonsurgical problems
• Acute myocardial infarction
• Exacerbation of chronic diseases
• diabetes or hypertension
• Anxiety and other mental health problems
• Respiratory disease caused by exposure to dust
  and asbestos fibers from rubble
• Near drowning caused by flooding from broken dams
  or tsunami

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More Problems

• Substantial morbidity following earthquakes can
  be caused by
• Building contents (e.g., glass, furniture,
  fixtures, appliances, chemical substances)
• Nonstructural elements (e.g., facade cladding,
  partition walls, roof parapets, external
  architectural ornaments)

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Tsunamis

• Submarine earthquakes can generate damaging
  tsunamis
• A tsunami can be created directly by underwater
  ground motion during earthquakes or by
  landslides, including underwater landslides.
• Can travel thousands of miles at speeds of 300
  600 mph bringing destruction to low-lying coastal
  areas, bays and harbors.

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Aftershocks

• Most earthquakes are followed by many aftershocks
• May be as strong as the main shock itself
• Many fatalities and serious injuries occurred
  from a strong aftershock
• 2 days after the September 19, 1985, Mexico City
  earthquake that killed an estimated 10,000
  people.
• Landslides may be triggered by an aftershock
• Some major debris flows start slowly with a minor
  trickle and then are triggered in waves.
• Sufficient warning allows a community to evacuate
  in time

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Time of Day

• Time of day is an important determinant of a
  population's risk for death or injury
• For example, the 1988 Armenia earthquake occurred
  at 1141 AM, and thus many people were trapped in
  schools, office buildings, or factories.

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Human-Generated Factors

• Fires and dam ruptures following an earthquake
  are examples of major human-caused complications
  that aggravate the destructive effects of the
  earthquake itself.
• Transportation may become difficult as roads and
  bridges are destroyed.

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Human-Generated Factors

• In industrialized countries, an earthquake may
  also be the cause of a major technological
  disaster
• Damaging or destroying
• nuclear power stations
• research centers
• hydrocarbon storage areas and complexes making
  chemical and toxic products
• can lead to many more deaths than those caused
  directly by the earthquake
• Note that in the recent Japanese earthquake,
  there was much more news about the reactors than
  the tsunami or the earthquake

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Fire Risks

• One of the most severe follow-on or secondary
  disasters that can follow earthquakes is fire.
• Fire caused by
• Overturned stoves
• Heating appliances
• Lights
• Other items that can ignite materials

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Fire Risks

• Historically, earthquakes in Japan that trigger
  urban fires cause 10 times as many deaths as
  those that do not. The Tokyo earthquake of 1923,
  which killed more than 140,000 people, is a
  classic example of the potential that fires have
  to produce enormous numbers of casualties
  following earthquakes.
• Fire was also a major cause of damage in the 1906
  San Francisco Earthquake.

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Dams

• Dams may fail
• Threat to communities downstream
• Inspection of all dams in the vicinity is
  required
• Rapid reduction of water levels behind any dam
  suspected of having structural damage

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(No Transcript)
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Landslides May 30, 1970 Peru disaster
Magnitude 7.9 A large mass of ice and rock
slid from a vertical face on Nevado Huascaran,
the highest peak in Peru Debris reached a
velocity of 280 km/hr traveled 11 km
horizontally in about 4 minutes at a mean
velocity of 165 km/hr. Buried the towns of
Yungay and Ranrahirca, The death toll in both
villages was 20,000.
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Structural Factors

• Type of housing construction is a major risk
  factor for injuries.
• Third world construction is a real factor
• Those living in newer style adobe houses are at
  highest risk for injury or death
• Those living in the traditional mud and stick
  construction houses are at less risk
• Traditional bamboo and paper construction used in
  Japan is quite earthquake tolerant.

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Structural Factors

• Type of housing construction is a major risk
  factor for injuries.
• By far the greatest proportion of victims have
  died in the collapse of unreinforced masonry
  (URM) buildings (e.g., adobe, rubble stone, or
  rammed earth) or unreinforced fired-brick and
  concrete-block masonry buildings that can
  collapse even at low intensities of ground
  shaking and will collapse very rapidly at high
  intensities.
• There are many homes built in this construction
  in the New Madrid area.

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Structural Factors (cont.)

• Wood-frame buildings such as suburban houses in
  California are among the safest structures one
  could be in during an earthquake.
• Indeed, these buildings are constructed of light
  wood elements--wood studs for walls, wood beams
  and joists for floors, and wood beams and rafters
  for roofs.

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Structural Factors (cont.)

• The relative safety of wood-frame buildings has
  been shown quantitatively following the 1990
  Philippine earthquake.
• People inside buildings constructed of concrete
  or mixed materials are three times more likely to
  sustain injuries
• Even if the wood-frame buildings did collapse,
  their potential to cause injury is much less than
  that of old stone buildings, like those often
  used for businesses, offices, or schools.

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Nonstructural factors

• Nonstructural elements and building contents have
  been known to fail and cause significant damage
  in past
• Facade cladding, partition walls, roof parapets,
  external architectural ornaments, unreinforced
  masonry chimneys, ceiling tiles, elevator shafts,
  roof water tanks, suspended ceilings and light
  fixtures, raised computer floors, and building
  contents such as heavy fixtures in hospitals are
  among the numerous nonstructural elements that
  can fall in an earthquake, sometimes causing
  injury or death.
• In high rise buildings, window breakage presents
  a significant risk to the people below.

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Factors Influencing Earthquake Morbidity And
Mortality
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Entrapment

• Entrapment appears to be the single most
  significant factor associated with death or
  injury.
• In the 1988 Armenia earthquake, death rates were
  67 times higher and injury rates more than 11
  times higher for people who were trapped than for
  those who were not.
• In the 1980 southern Italian earthquake,
  entrapment requiring assistance to escape was the
  most important risk factor the death rate was
  35 for trapped people versus 0.3 for untrapped
  people.
• In the Philippine earthquake of 1990, people who
  died were 30 times more likely to have been
  trapped than were injured survivors.

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Occupants Behavior

• The behavior of people during an earthquake is an
  important predictor of their survival.
• In several recent earthquakes (e.g., 1990
  Philippines and 1992 Egypt earthquakes), there
  were widespread reports of deaths and injuries
  due to stampedes, as panicked building occupants
  and students rushed for the nearest exits.
• On the other hand, a review of the first reaction
  of people following an initial earthquake shock
  revealed that those who immediately ran out of
  buildings had a lower incidence of injury than
  did those who stayed inside.

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Occupants Behavior

• Other reports, however, suggest that running
  outside may actually increase the risk of injury.
  
• During the 1976 Tangshan earthquake, many were
  struck by the collapse of outer walls after
  running out of their houses.
• In modern high-rise buildings, falling glass can
  be lethal.

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Time Until Rescue

• Although the probability of finding live victims
  diminishes very rapidly with time, entrapped
  people have survived for many days.
• People have been rescued alive 5, 10, and even 14
  days after an earthquake
• These "miracle rescues" are often the result of
  exceptional circumstances--for example, someone
  with very light injuries is trapped in a void
  deep in the rubble with air and possibly water
  available.

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Disaster Response to Earthquakes

• Prompt rescue should improve the outcome of
  victims
• Early medical treatment should lessen the
  sequellae of the primary injuries
• Provision of adequate food, water, and shelter
  should help people in vulnerable age groups and
  those with pre-existing diseases.
• Effective environmental control measures should
  prevent secondary environmental health problems.
• Identification and control of long-term hazards
  (e.g., asbestos in rubble) should reduce chronic
  health effects.

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Search and Rescue

• People trapped in the rubble will die if they are
  not rescued and given medical treatment
• Search and rescue teams responding rapidly after
  a building collapse maximizes trapped victims
  chances of survival

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Search and Rescue (cont.)

• Foreign assistance usually arrives after the
  local community has already engaged in much of
  the rescue activity
• Exceptions
• Personnel from neighboring countries in close
  geographical proximity

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Monitoring Our Responses

• Conduct of future rescue operations can be
  enhanced by lessons learned from the position and
  circumstances of trapped victims and from
  specific details about the extrication process
  itself.
• Knowledge of collapse conditions helps set rescue
  priorities

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Medical Treatment

• Just as speed is required for effective search
  and extrication, it is also essential for
  effective emergency medical services.
• The greatest demand occurs within the first 24
  hours.
• Ideally, "disaster medicine" (medical care for
  victims of disaster) would include immediate
  life-supporting first aid (LSFA), advanced trauma
  life support (ATLS), resuscitative surgery, field
  analgesia and anesthesia, resuscitative
  engineering (search and rescue technology), and
  intensive care.
• This may not be readily available when local
  hospitals and response agencies are damaged.

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Medical Treatment (cont.)

• The medical and public health impact of a severe
  earthquake may well be compounded by significant
  damage to medical facilities, hospitals, clinics
  and supply stores within the affected area.
• In the worst-case scenario, a hospital building
  may itself be damaged by the earthquake, and the
  hospital staff may have to continue emergency
  treatment without using the buildings.

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Surveillance of Injuries at Medical Treatment
Sites

• Treatment sites, whether at hospitals or in
  temporary field clinics should designate someone
  to organize surveillance of injuries, collect
  data, and see that the data are tabulated and
  reported to disaster-response health officials.

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Dissemination of Public Health Information

• Public health should work out scenarios for
  various information-dissemination contingencies
  before an earthquake occurs.
• This will be difficult.
• Telephone service is likely to be disrupted in
  the impact area of an earthquake.
• However, police, fire, and many emergency service
  organizations maintain radio networks, which
  public health officials may be able to use.
• Amateur radio may be of immense assistance
• Radio and television news crews often arrive at
  the scene of a disaster with sophisticated
  communications equipment.

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Environmental Health

• In the day or so immediately following an
  earthquake, the priorities are undoubtedly
  rescuing and treating victims.
• Saving the lives of those injured or trapped far
  outweighs most other needs.
• Other needs of a population suddenly deprived of
  homes, possessions, urban services, and other
  essentials cannot be ignored and will assume
  greater significance as soon as the
  life-threatening situation stabilizes.

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Environmental Health

• If large areas of buildings are destroyed, the
  population made homeless will have an urgent need
  for shelter and food.
• They will need drinking water, clothing,
  sanitation, hygiene education, and basic comfort
  provision.
• This may be difficult to provide when
  infrastructure has been damaged.
• Effective environmental control measures should
  prevent secondary environmental health problems.

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Critical Knowledge Gaps

• Because we do not know enough about the precise
  causes of deaths and nature of injuries that
  occur during earthquakes, relief services are
  often misdirected and community medical/health
  planning for earthquakes is often inadequate.
• The more we know, the better we can prepare for
  and respond to earthquakes. The following are
  steps researchers can take to help health
  officials and individuals better prepare for
  future earthquakes.

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Epidemiology Research

• Few earthquakes have been adequately studied
  epidemiologically.
• In most cases, we simply dont know what position
  people were in when the quake struck and killed
  them. We also dont know what saves survivors.
• Good disaster medicine research requires that
  plans for follow-up epidemiology be developed
  before an earthquake occurs so that the initial
  surveillance data collected will allow proper
  follow-up and analysis of the data.

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Critical Knowledge Gaps (cont.)

• Evaluate the role of occupant behavior in
  earthquake injury susceptibility.
• Collect more extensive data concerning the
  circumstances of entrapment (e.g., location of
  victims in the collapsed structure).
• Lack of such data has made planning search and
  rescue actions, providing proper medical care,
  and requesting the appropriate outside aid more
  difficult.

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Critical Knowledge Gaps (cont.)

• Incorporate post-earthquake research findings
  into specific emergency-preparedness and
  response-guidance protocols.
• The gap between what researchers have learned and
  the knowledge base underlying the protocols of
  the "user community" (e.g., response and recovery
  organizations) can be lessened considerably if
  researchers and members of the user community
  interface more effectively.
• Results of research should be at national, state,
  and local levels so that they can incorporate
  such findings into community earthquake-preparedne
  ss and earthquake-response programs.

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Methodologic Problems

• The data needed for comparative earthquake
  studies is often lacking, including such basic
  information as the magnitude or intensity of the
  earthquake, the number of deaths, the number of
  people injured (using standard definitions) and
  the size of the affected population.
• The study of earthquake injuries is difficult to
  approach from any narrow background, as it
  requires the active collaboration of researchers
  with a number of areas of expertise.
• First, one must understand the mechanisms of
  physical failure in earthquakes. This requires
  structural engineering and architectural
  competence.

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Methodologic Problems

• Second, one must understand the process of human
  injury in earthquake-induced building failure.
• Third, one must develop the analytical framework
  for the analysis of injury patterns and for the
  analysis of the relationship between specific
  causative agents and negative consequences.

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Methodologic Problems

• One must consider
• Hazard exposure
• Construction types and their performance during
  earthquakes
• Influence of nonstructural components, building
  components, and building contents
• Building occupancy and the behavior of occupants
• Emergency and rescue response
• Medical treatment provided
• These plans for research must be done in advance
  "backtracking" injuries from hospitals to
  specific building-collapse sites may be
  impossible.

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Earthquake size two ways to measure

• Magnitude Richter Scale
• Measures the energy released by fault movement
• related to the maximum amplitude of the S wave
  measured from the seismogram
• Logarithmic-scale quantitative measure
• For each whole number there is a 31.5 times
  increase in energy
• eg. an increase from 5 to 7 on the Richter scale
  an increase in energy of 992 times!!

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• 2) Intensity Mercalli Scale
• What did you feel?
• Assigns an intensity or rating to measure an
  earthquake at a particular location (qualitative)
• I (not felt) to XII (buildings nearly destroyed)
• Measures the destructive effect
• Intensity is a function of
• Energy released by fault
• Geology of the location
• Surface substrate can magnify shock waves e.g.
  Mexico City (1985) and San Francisco (1989)

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Earthquake Preparedness

• Develop a home earthquake plan.
• Conduct earthquake drills.
• Develop a plan for reuniting family members.
• Identify an out-of-state family contact.
• Keep supplies on hand.

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Earthquake Preparedness

• Store heavy and breakable objects on low shelves.
• Secure bookshelves and water heaters.
• Install flexible pipe.
• Move beds away from windows.
• Move or secure hanging objects over beds, sofas,
  or chairs.
• Keep shoes and a flashlight under the bed.

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During an Earthquake

• Drop, cover, and hold.
• If indoors, stay there!
• If outdoors, find a spot away from buildings,
  trees, streetlights and power lines, and
  overpasses.
• If in a vehicle, drive to a clear spot and stop.

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After an Earthquake

• Extinguish small fires.
• Clean up spills.
• Inspect home for damage.
• Help neighbors.
• Tune to Emergency Alert System (EAS).
• Expect aftershocks.

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Take-Away Points

1. Earthquakes generate waves that travel through
   the earth
2. Earthquakes occur when rocks slip along faults
3. Faults are classified by the kinds of movement
   that occur along them
4. Earthquakes dont kill people, buildings kill
   people
5. Magnitude and Intensity
6. Seismic waves are used to map the earths
   interior
7. Predicting earthquakes is not yet possible

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Charles Stewart MD EMDM, MPHcharles-e-stewart_at_ouh
sc.edu