What is an earthquake?

Answer 1

Earthquakes are tremors or vibrations in the Earth's crust that are caused by the build up or accumulation of pressure (more correctly termed stress).

More:

The Earth's crust, or lithosphere (hard outer surface) is made up of "tectonic plates", or large plates. There are about 7 major plates and many smaller plates, around 100 km thick, which sit upon a lower soft layer (the asthenosphere). The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.

This accumulation of stress causes the rocks that make up the crust to deform elastically. This is very similar to what happens when you squash or stretch a spring and causes a form of energy to be stored in the rocks of the crust - technically described as elastic potential energy.

When this stress gets too large, it exceeds the strength of the rocks in the crust and causes a brittle failure. Brittle failures are failures where fractures form through the material. As these have been happening for a long time, the earth's lithosphere is already fractured. These fractures are known as faults and as these represent zones of weakness within the lithosphere, it is along faults where the majority of earthquake occur when they slip suddenly.

This sudden brittle failure causes all of the elastic potential energy to be released at one time in the form of seismic waves, just as if a spring or elastic band that was being stretched suddenly snapped.

These seismic waves cause the tremors that people feel on the surface and which can cause damage to buildings and other structures.

Please see the related links for more information.

The Earth's crust, or lithosphere (hard outer surface) is made up of "tectonic plates", or large plates. There are about 7 major plates and many smaller plates, around 100 km thick, which sit upon a lower soft layer (the asthenosphere).

When these plates move against each other along plate boundaries (where two plates meet) or along faults (a rift), an earthquake occurs. This may be through a variety of movements: sideways, up and down or apart. This causes anything upon the upper surface, above the earthquake, to also shift, whether they be buildings, roads, bridges, railways, etc.

What you actually feel when you feel the shaking of an earthquake are the seismic waves.

There are three types of seismic waves and they are determined by the properties of the rock through which they travel:

P-waves (compressional waves) or primary waves are the first waves: they travel the fastest and can travel through everything.

Then the S-waves (shear waves) or secondary waves come: they move slower and cannot travel through liquids.

At last the Surface-waves come. They are the slowest and they cause the biggest damage. Often it is when the surface-waves come that the buildings collapse.

An earthquake describes when the earth moves the ground under your feet. It can slide it from side to side or move it a few feet in one direction. It can lift it up in one place and make it sink in another. The results of this are quite visible in and near Anchorage, Alaska. One street in that town shows where an earthquake make the ground fell. Driving south, dead trees stick up out of a lake where the ground fell below sea level. Earthquakes are caused when faults or cracks in the earth's shell suddenly slip past each other. When they jerk, they move a lot of land with them. That makes the earth tremble. Sometimes it damages buildings.

The official definition for the word earthquake is "a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action." knowing these earthquakes happen almost everywhere they do most take place in the U.S

in the state of California just a (FYI)
tectonic plates- move in 3 ways

1. collide w/ eachother

2.seperate from eachother

3. slide against eachother

when plates are moved to the breaking point it causes an eartquake

an earthquake is a seismic wave

Answer 2

slowest,causes the ground to twist and bend.

Answer 3

Earthquakes are tremors or vibrations in the Earth's crust that are caused by the build up or accumulation of pressure (more correctly termed stress).

More:

The Earth's crust, or lithosphere (hard outer surface) is made up of "tectonic plates", or large plates. There are about 7 major plates and many smaller plates, around 100 km thick, which sit upon a lower soft layer (the asthenosphere). The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earth's crust and cause the shaking that we feel.

This accumulation of stress causes the rocks that make up the crust to deform elastically. This is very similar to what happens when you squash or stretch a spring and causes a form of energy to be stored in the rocks of the crust - technically described as elastic potential energy.

When this stress gets too large, it exceeds the strength of the rocks in the crust and causes a brittle failure. Brittle failures are failures where fractures form through the material. As these have been happening for a long time, the earth's lithosphere is already fractured. These fractures are known as faults and as these represent zones of weakness within the lithosphere, it is along faults where the majority of earthquake occur when they slip suddenly.

This sudden brittle failure causes all of the elastic potential energy to be released at one time in the form of seismic waves, just as if a spring or elastic band that was being stretched suddenly snapped.

These seismic waves cause the tremors that people feel on the surface and which can cause damage to buildings and other structures.

Please see the related links for more information.

The Earth's crust, or lithosphere (hard outer surface) is made up of "tectonic plates", or large plates. There are about 7 major plates and many smaller plates, around 100 km thick, which sit upon a lower soft layer (the asthenosphere).

When these plates move against each other along plate boundaries (where two plates meet) or along faults (a rift), an earthquake occurs. This may be through a variety of movements: sideways, up and down or apart. This causes anything upon the upper surface, above the earthquake, to also shift, whether they be buildings, roads, bridges, railways, etc.

What you actually feel when you feel the shaking of an earthquake are the seismic waves.

There are three types of seismic waves and they are determined by the properties of the rock through which they travel:

P-waves (compressional waves) or primary waves are the first waves: they travel the fastest and can travel through everything.

Then the S-waves (shear waves) or secondary waves come: they move slower and cannot travel through liquids.

At last the Surface-waves come. They are the slowest and they cause the biggest damage. Often it is when the surface-waves come that the buildings collapse.

An earthquake describes when the earth moves the ground under your feet. It can slide it from side to side or move it a few feet in one direction. It can lift it up in one place and make it sink in another. The results of this are quite visible in and near Anchorage, Alaska. One street in that town shows where an earthquake make the ground fell. Driving south, dead trees stick up out of a lake where the ground fell below sea level. Earthquakes are caused when faults or cracks in the earth's shell suddenly slip past each other. When they jerk, they move a lot of land with them. That makes the earth tremble. Sometimes it damages buildings.

The official definition for the word earthquake is "a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action." knowing these earthquakes happen almost everywhere they do most take place in the U.S

in the state of California just a (FYI)
tectonic plates- move in 3 ways

1. collide w/ eachother

2.seperate from eachother

3. slide against eachother

when plates are moved to the breaking point it causes an eartquake

an earthquake is a seismic wave

Answer 4

Earthquake are caused by the movement of Tectonic Plate beneath the Earth's surface.

Answer 5

An earthquake is when the tectonic plates move across each other, this will cause the floor to shake and rumble meaning everything will collapse beacause of the shaking