Anonymous
Anonymous asked in Science & MathematicsEarth Sciences & Geology · 1 decade ago

# Earthquakes?

What is an earthquake?

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An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. (figure 1)

http://www.yard9.com/2007/09/05/what-is-an-earthqu...

An earthquake is a release of built up energy in the earth’s crust. This causes the earth to move and break apart causing damage to the earth’s surface.

Details: The earth is composed if the inner core, outer core, mantle and the crust. An earthquake actually takes place in the lithosphere, which is the outer solid portion of the earth including the crust and the upper most mantle.

A fault is a place where the lithosphere is cracked. Rock movement in the mantle causes stress to build up. When this pressure reaches a breaking point, the plates slide past one another, away from each other, or into each other and an earthquake occurs.

They usually come from the movement of 2 plates but can be created by volcanic activity as well in the crust.

The movements of the plates create stress and an earthquake is the releasing of this stress. Stress is created by the pull of the 2 plates, rubbing along side each other or being pushed together. When being pushed together the crust will either be pushed upwards like the Himalayas or one forced down (Subduction Zone) as seen off the Japan Coast. When the crust is forced down you tend to see volcanoes in the area. These are formed by the melting of the crust being forced down and then again rising to the surface. This is how Japan was formed.