# Earthquakes

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An earthquake is a sudden shaking of the earth caused by the breaking
and shifting of rock beneath the earth's surface. Earthquakes can cause
buildings and bridges to collapse, telephone and power lines to fall,
and result in fires, explosions and landslides. Earthquakes can also
cause huge ocean waves, called tsunamis, which travel long distances
over water until they crash into coastal areas.

The following information includes general guidelines for earthquake
preparedness and safety. Because injury prevention techniques may vary
from state to state, it is recommended that you contact your local
emergency management office, health department, or American Red Cross
chapter.

### What to do before an earthquake

1.  Know the terms associated with earthquakes.

    -   **Earthquake**­---a sudden slipping or movement of a portion of
        the earth's crust, accompanied and followed by a series of
        vibrations.

    -   **Aftershock**---an earthquake of similar or lesser intensity
        that follows the main earthquake.

    -   **Fault---**the fracture across which displacement has occurred
        during an earthquake. The slippage may range from less than an
        inch to more than 10 yards in a severe earthquake.

    -   **Epicenter---**the place on the earth\'s surface directly above
        the point on the fault where the earthquakes rupture began. Once
        fault slippage begins, it expands along the fault during the
        earthquake and can extend hundreds of miles before stopping.

    -   **Seismic Waves**---are vibrations that travel outward from the
        earthquake fault at speeds of several miles per second. Although
        fault slippage directly under a structure can cause considerable
        damage, the vibrations as seismic wave pass by cause most of the
        destruction during earthquakes.

    -   **Magnitude**---computed from the amplitude of the seismic
        waves, the magnitude indicates how much energy was released
        during an earthquake. A magnitude of 7.0 on the Richter Scale
        would indicate a very strong earthquake. Each whole number on
        the scale represents an increase of about 30 times the energy
        released. Therefore, an earthquake measuring 6.0 is about 30
        times more powerful than one measuring 5.0.

    -   Look for items in your home that could become a hazard in an
        earthquake:

    -   Repair defective electrical wiring, leaky gas lines, and
        inflexible utility connections.

    -   Bolt down and secure to wall your water heater, refrigerator,
        furnace, and gas appliances. If recommended by your gas company,
        have an automatic gas shut-off valve installed that is triggered
        by strong vibrations).

    -   Place large or heavy objects on lower shelves. Fasten shelves to
        walls. Brace high and top-heavy objects.

    -   Store bottled foods, glass, china and other breakables on low
        shelves or in cabinets that can fasten shut.

    -   Anchor overhead lighting fixtures.

    -   Check and repair deep plaster cracks in ceilings and
        foundations. Get expert advice, especially if there are signs of
        structural defects.

    -   Be sure the residence is\
        firmly anchored to its foundation.

    -   Install flexible pipe fittings to avoid gas or water leaks.
        Flexible fittings are more resistant to breakage.

2.  Know where and how to shut off electricity, gas and water at main
    switches and valves. Check with your local utilities for
    instructions. Do not actually shut off the gas to see how it works
    or to show others. Only the gas company can safely turn it back on.

3.  Hold earthquake drills with your household:

    -   Locate safe spots in each room under a sturdy table or against
        an inside wall. Reinforce this information by physically placing
        yourself and your household in these locations.

4.  Identify danger zones in each room---near windows where glass can
    shatter, bookcases or furniture that can fall over, or under ceiling
    fixtures that could fall down.

5.  Develop a plan for reuniting your household after an earthquake.
    Establish an out-of-town telephone contact for household members to
    call to let others know that they are okay.

6.  Review your insurance policies. Some damage may be covered even
    without specific earthquake insurance. Protect important home and
    business papers.

7.  Prepare to survive on your own for at least three days. Assemble a
    disaster supply kit. Keep a stock of food and extra drinking water.
    See the "Emergency Planning and Disaster Supplies" and "Evacuation"
    chapters for more information.

### What to do during an earthquake

Stay inside until the shaking stops and it is safe to go outside. Most
injuries during earthquakes occur when people are hit by falling objects
when entering or exiting buildings.

1.  Drop, Cover and Hold On! Minimize your movements during an
    earthquake to a few steps to a nearby safe place. Stay indoors until
    the shaking has stopped and you are sure exiting is safe.

2.  If you are indoors, take cover under a sturdy desk, table or bench,
    or against an inside wall, and hold on. Stay away from glass,
    windows, outside doors or walls and anything that could fall, such
    as lighting fixtures or furniture. If you are in bed, stay there,
    hold on and protect your head with a pillow, unless you are under a
    heavy light fixture that could fall.

3.  If there isn't a table or desk near you, cover your face and head
    with your arms and crouch in an inside corner of the building.
    Doorways should only be used for shelter if they are in close
    proximity to you and if you know that it is a strongly supported
    load-bearing doorway.

4.  If you are outdoors, stay there. Move away from buildings,
    streetlights and utility wires.

5.  If you live in an apartment building or other multi-household
    structure with many levels, consider the following:

    -   Get under a desk and stay away from windows and outside walls.

    -   Stay in the building (many injuries occur as people flee a
        building and are struck by falling debris from above).

    -   Be aware that the electricity may go out and sprinkler systems
        may come on.

    -   DO NOT use the elevators.

6.  If you are in a crowded indoor public location:

    -   Stay where you are. Do not rush for the doorways.

    -   Move away from tall objects that may fall.

    -   Take cover and grab something to shield your head and face from
        falling debris and glass.

    -   Be aware that the electricity may go out or the sprinkler
        systems or fire alarms may turn on.

    -   DO NOT use elevators.

7.  In a moving vehicle, stop as quickly as safety permits, and stay in
    the vehicle. Avoid stopping near or under buildings, trees,
    overpasses or utility wires. Then, proceed cautiously, watching for
    road and bridge damage.

8.  If you become trapped in debris:

    -   Do not light a match.

    -   Do not move about or kick up dust.

    -   Cover your mouth with a handkerchief or clothing.

    -   Tap on a pipe or wall so rescuers can locate you. Use a whistle
        if one is available. Shout only as a last resort---shouting can
        cause you to inhale dangerous amounts of dust.

9.  Stay indoors until the shaking has stopped and you are sure exiting
    is safe.

### What to do after an earthquake

1.  Be prepared for aftershocks. These secondary shock waves are usually
    less violent than the main quake but can be strong enough to do
    additional damage to weakened structures.

2.  Check for injuries. Do not attempt to move seriously injured persons
    unless they are in immediate danger of death or further injury. If
    you must move an unconscious person, first stabilize the neck and
    back, then call for help immediately.

    -   If the victim is not breathing, carefully position the victim
        for artificial respiration, clear the airway and start
        mouth-to-mouth resuscitation.

    -   Maintain body temperature with blankets. Be sure the victim does
        not become overheated.

    -   Never try to feed liquids to an unconscious person.

3.  If the electricity goes out, use flashlights or battery powered
    lanterns. Do not use candles, matches or open flames indoors after
    the earthquake because of possible gas leaks.

4.  Wear sturdy shoes in areas covered with fallen debris and broken
    glass.

5.  Check your home for structural damage. If you have any doubts about
    safety, have your residence inspected by a qualified building
    inspector or structural engineer before entering.

6.  Check chimneys for visual damage; however, have a professional
    inspect the chimney for internal damage before lighting a fire.

7.  Clean up spilled medicines, bleaches, gasoline and other flammable
    liquids. Evacuate the building if gasoline or other fumes are
    detected and the building is not well ventilated. Ventilate by
    opening windows and doorways to the outside.

8.  Visually inspect utility lines and appliances for damage.

    -   If you smell gas or hear a hissing or blowing sound, open a
        window and leave. Shut off the main gas valve. Report the leak
        to the gas company from the nearest working phone or cell phone
        available. Stay out of the building. If you shut off the gas
        supply at the main valve, you will need a professional to turn
        it back on.

    -   Switch off electrical power at the main fuse box or circuit
        breaker if electrical damage is suspected or known.

    -   Shut off the water supply at the main valve if water pipes are
        damaged.

    -   Do not flush toilets until you know that sewage lines are
        intact.

9.  Open cabinets cautiously. Beware of objects that can fall off
    shelves.

10. Use the phone only to report life-threatening emergencies.

11. Listen to news reports for the latest emergency information.

12. Stay off the streets. If you must go out, watch for fallen objects,
    downed electrical wires, weakened walls, bridges, roads and
    sidewalks.

13. Stay away from damaged area unless your assistance has been
    specifically requested by police, fire or relief organizations.

14. If you live in coastal areas, be aware of possible tsunamis,
    sometimes mistakenly called tidal waves. When local authorities
    issue a tsunami warning, assume that a series of dangerous waves is
    on the way. Stay away from the beach. See the "Tsunamis" chapter for
    more information.