What causes earth quakes!!!!!!!!?

Question

What causes earth quakes!!!!!!!!?

Answer 1

The short answer is that earthquakes are caused by faulting, a sudden lateral or vertical movement of rock along a rupture (break) surface.

    Here's the longer answer: The surface of the Earth is in continuous slow motion. This is plate tectonics--the motion of immense rigid plates at the surface of the Earth in response to flow of rock within the Earth. The plates cover the entire surface of the globe. Since they are all moving they rub against each other in some places (like the San Andreas Fault in California), sink beneath each other in others (like the Peru-Chile Trench along the western border of South America), or spread apart from each other (like the Mid-Atlantic Ridge). At such places the motion isn't smooth--the plates are stuck together at the edges but the rest of each plate is continuing to move, so the rocks along the edges are distorted (what we call "strain"). As the motion continues, the strain builds up to the point where the rock cannot withstand any more bending. With a lurch, the rock breaks and the two sides move. An earthquake is the shaking that radiates out from the breaking rock.

    People have known about earthquakes for thousands of years, of course, but they didn't know what caused them. In particular, people believed that the breaks in the Earth's surface--faults--which appear after earthquakes, were caused *by* the earthquakes rather than the cause *of* them. It was Bunjiro Koto, a geologist in Japan studying a 60-mile long fault whose two sides shifted about 15 feet in the great Japanese earthquake of 1871, who first suggested that earthquakes were caused by faults. Henry Reid, studying the great San Francisco earthquake of 1906, took the idea further. He said that an earthquake is the huge amount of energy released when accumulated strain causes a fault to rupture. He explained that rock twisted further and further out of shape by continuing forces over the centuries eventually yields in a wrenching snap as the two sides of the fault slip to a new position to relieve the strain. This is the idea of "elastic rebound" which is now central to all studies of fault rupture

Answer 2

The tectonic plates under our crust is having number of broken plates.These plates are moving at the rate of 50 to 100 mm per year due to convection of heat under it.This causes Creation of stress in plate boundary.At a particular stage it slips to release the accumulated stress.This causes the creation of earthquakes.

Answer 3

movements of tectonic plates underground, mainly in fault line regions. the pressure exrted by the earth's core is what gets it to move.

Answer 4

An earthquake is the shaking of the ground caused by an abrupt shift of rock along a fracture in the Earth, called a fault. Within seconds, an earthquake releases stress that has slowly accumulated within the rock, sometimes over hundreds of years. The size of an earthquake is indicated by a number called its magnitude. Magnitude is calculated from a measurement of either the amplitude or the duration of specific types of recorded seismic waves. Magnitude is determined from measurements made from seismograms and not on reports of shaking or interpretations of building damage. The intensity of and earthquake is a measure of the amount of ground shaking at a particular site, and it is determined from reports of human reaction to shaking, damage done to structures, and other effects.

Earth scientists believe that most earthquakes are caused by slow movements inside the Earth that push against the Earth's brittle, relatively thin outer layer, causing the rocks to break suddenly. This outer layer is fragmented into a number of pieces, called plates. Most earthquakes occur at the boundaries of these plates. In Washington State, the small Juan de Fuca plate off the coast of Washington, Oregon, and northern California is slowly moving eastward beneath a much larger plate that includes both the North American continent the land beneath part of the Atlantic Ocean. Plate motions in the Pacific Northwest result in shallow earthquakes widely distributed over Washington and deep earthquakes in the western parts of Washington and Oregon. The movement of the Juan de Fuca plate beneath the North America plate is in many respects similar to the movements of plates in South America, Mexico, Japan, and Alaska, where the world's largest earthquakes occur.

Answer 5

Flixy is right...........

These clashes of plates are caused by men by

  # Boring for under ground Water

  # Drilling for Stone

  # taking Petroleum etc.......These are reasons .........

This is known as a Manmade Disaster....

Answer 6

An earthquake is any motion of the ground,no matter what is the cause.They usually happen as a result of the release of energy when rocks come under pressure,mainly from plate movements,shift or fracture.A few earhquakes are triggered by meteorite impacts,man-made explosions,or the weight of water,for instance behind a dam.More details about how it happens are given below.

When rocks can no longer absorb the build-up pressure they break or shift along faultlines,releasing the pent-up energy as waves of vibrations radiating from the centre,or focus,of the failure.We feel the surface waves as an earthquake,which can last just a few seconds or as long as four minutes.

Answer 7

The movement of the tectonic plates causes the earthquakes.