EARTHQUAKES

OBJECTIVE

• Causes
• Seismic waves
• Damage
• Type of earthquakes
• Earthquake clip and drill

CAUSES

• An earthquake is caused by a sudden slip on a fault
• much like what happens when you snap your fingers. Before you push your fingers
• Because you are pushing them together, friction keeps them from moving
• When you push sideways hard enough to overcome this friction, your fingers move suddenly,
• releasing energy in the form of sound waves that set the air vibrating and travel.

Seismic waves
There are two main types of body waves (P and S waves ), but there is also a third type called Surface Waves. Surface Waves are a mixture of the two wave patterns together.

Damage
An earthquake range of damage is very broad. An earthquake can cause buildings to fall,pipes to burst and bridges to collapse .

There are four different types of earthquakes: Tectonic, volcanic, collapse and explosion.

• A tectonic earthquake is one that occurs when the earth's crust breaks due to geological forces on rocks and adjoining plates that cause physical and chemical changes.
• A volcanic earthquake is any earthquake that results from tectonic forces which occur in conjunction with volcanic activity.
• A collapse earthquake are small earthquakes in underground caverns and mines that are caused by seismic waves produced from the explosion of rock on the surface.
• An explosion earthquake is an earthquake that is the result of the detonation of a nuclear and/or chemical device.

CLIP SHOW ON EARTHQUAKE

EARTHQUAKE DRILL

• You have 30seconds to perform the correct actions and reactions during a earthquake
• Find a safe place away from windows
• Grab what ever YOU think you need
• Duck.Cover.Hold on

EARTHQUAKE ASSEMENT

• How do we measure earthquakes?
• What is the first step during an earthquake ?
• What can happen as a result of a earthquake (damage)?