Earthquake Damage Unit

Where would you be the safest in anearthquake?

•Open level field away from buildings

•Movement of the ground rarely causes deaths orinjuries

•Deaths and injuries result from collapse ofbuildings or structures, flying objects and glass

•Landslides, fires, explosions caused by brokenelectric and gas lines and floodwaters frombroken dams also cause death and injuries

•A moderate earthquake that continues for a longtime can cause more damage that a shorterearthquake of higher magnitude

Destruction of Buildings andProperties

•Buildings with weak walls may totally collapse

•Tall buildings sway so violently they tip over anddestroy anything around them

•Type of ground a building is built on affectswhether or not a building survives

•Buildings built on loose soil and rock is morelikely to be damaged than one built on solidground

•On what type of ground should a tall building inan earthquake – prone region be constructed?

Tsunamis

•Giant ocean wave caused by a major earthquake with an epicenterthe ocean floor

•May be caused in two ways

•Faulting- causes a sudden drop or rise in the ocean floor

•A large mass of sea water also drops or rises with the ocean floor

•This water then churns and causes violent movement of waterresulting in a Tsunami

•Underwater landslides – water above a landslide is thrown into anup and down motion creating a series of tsunamis

•1964 Alaskan earthquake: tsunami caused 107 deaths and only 9people died as a result of the earthquake

•Seismograph stations now also monitor sea waves to warn ofimpending tsunamis

Earthquake Safety

•Before an earthquake occurs be prepared

•What are some ways in which you could beprepared? Supply of canned food, bottledwater, flashlights, batteries and portable radio.Have a plan. Learn how to turn of the gas,electricity and water in your home.

•Stay calm

•Move to a safer position

Earthquake Safety Cont.

•Where do you think a safe position would be?Indoors, stand in a doorway or crouch under adesk or table. Stay away from windows, heavyfurniture and other objects that might toppleover. Do out run outside. If you are in a cardrive away from tall buildings, tunnels andpower lines, bridges and stay in your car.

•After an earthquake be cautious

•Check for fire hazards

Earthquake Warnings and Predictions

•Animal behaviors – earliest means ofpredicting earthquakes

•Animals appeared nervous and restless

•Scientists are trying to detect changes in theearth’s crust that can signal an approachingearthquake.

•Place instruments along rocks in faults

•They can detect rock movement and increasein stress

Earthquake Warnings and Predictions

•Seismic gaps place where the fault is locked andunable to move

•Stress in surrounding rocks has increased and nomajor earthquake has occurred in this locationfor at least 30 years

•Scientist believe seismic gaps are likely locationsof future earthquakes

•Several seismic gaps exist along the San Andreasfault

•Slight tilting of the ground shortly before anearthquake can be used as a prediction

Study Questions for EarthquakeDamage Unit

•How do tall buildings usually respond during a major earthquake?

•What causes tsunamis?

•What should you do if an earthquake strikes while you are athome? In a car?

•What are some early warning signs of earthquake activity?

• What type of building construction and locations regulationsshould be included in the building code of a city located near anactive fault?