What to Do in Case of … an Earthquake
About Earthquakes
An earthquake is the sudden release of stored energy; most earthquakes occur along a fracture within the earth, called a fault. The shaking caused by this sudden shift is often very small, but occasionally large earthquakes produce very strong ground shaking. It is this strong shaking and its consequences – ground failure, landslides, liquefaction – that damages buildings and structures and upsets the regional economy.
Washington, especially the Puget Sound basin, has a history of frequent earthquakes. More than 1,000 earthquakes occur in the state each year. A dozen or more are strong enough that people feel ground shaking; occasionally, earthquakes cause damage. Large earthquakes in 1946 (magnitude 5.8), 1949 (magnitude 7.1) and 1965 (magnitude 6.5) killed 15 people and caused more than $200 million (1984 dollars) in damage throughout several counties. The state experienced at least 20 damaging events in the last 125 years.
The Nisqually earthquake on February 28, 2001, was a deep, magnitude 6.8 earthquake 10 miles northeast of Olympia. One person died of a heart attack, more than 700 people were injured, and various estimates place damage at between $1 billion and $4 billion; exact figures are not available, as insurance claims information is not available.
The earthquake threat in Washington is not uniform. While most earthquakes occur in Western Washington, some damaging events, such as the 1872 magnitude 6.8 (est.) quake, do occur east of the Cascades. Geologic evidence documents prehistoric magnitude 8 to 9.5 earthquakes along the outer coast, and events of magnitude 7 or greater along shallow crustal faults in the urban areas of Puget Sound.
Washington’s earthquake hazards reflect its tectonic setting. The Pacific Northwest is at a convergent continental margin, the collision boundary between two tectonic plates of the earth’s crust. The Cascadia subduction zone, the fault boundary between the North America plate and the Juan de Fuca plate, lies offshore from northern California to southern British Columbia. The two plates are converging at a rate of about 2 inches per year. In addition, the northward-moving Pacific plate is pushing the Juan de Fuca plate north, causing complex seismic strain to accumulate. The abrupt release of this slowly accumulated strain causes earthquakes.
What to do before an earthquake:
- Prepare disaster supply kits for your home, workplace, and vehicle.
- Find out who in your area might need special assistance, specifically the elderly, disabled, or non-English speaking neighbors.
- Know the emergency plans for Northwest University.
- Know the risks for areas you visit.
- Conduct a home hazard evaluation.
- Anchor appliances and tall heavy furniture that might fall. Put latches on cabinet doors to keep contents from spilling out.
- Establish an “out-of-area” contact and keep the telephone number handy. This is the person family members will call if you are separated.
What to do during an earthquake:
If you are INDOORS:
- Stay inside!
- Don’t panic or run.
- DROP, COVER and HOLD. DROP to the floor, COVER yourself under a desk or sturdy table and HOLD onto its legs. If it moves, move with it.
- If you are in a crowded room do not rush for the exits. Move away from anything that may fall and DROP, COVER and HOLD.
- Do not use elevators.
- Do not attempt to leave until the shaking stops.
If you are OUTDOORS:
- Stay outdoors!
- Move to an open area away from trees, signs, buildings, or utility wires and poles.
- If you are on a sidewalk near a tall building, get into a doorway or lobby to protect yourself from falling bricks, glass and other debris.
If you are DRIVING:
- Pull over to the side of the roadway and stop.
- Avoid overpasses, power lines, and other hazards.
- Stay in the vehicle until the shaking stops.
- Listen to your radio for emergency instructions.
What to do after an earthquake:
- Check yourself and those around you for injuries.
- Evacuate damaged buildings. Do not reenter until declared safe by authorities.
- Call 9-1-1 only to report a life threatening emergency.
- If you smell gas or hear a hissing sound – open windows and leave the building. Do not use matches, candles, open flames or electric switches indoors.
- Provide assistance to your neighbors.
- Try to make contact with your out of area phone contact, but do not make local calls.
- Monitor local radio stations for instructions or an offical “all clear” notice. Radio stations will broadcast what to do, the location of emergency shelters, medical aid stations, and extent of damage.