Earthquarkes

media type="custom" key="7235179" =What is an earthquake?= An earthquake is the shaking and vibration at the face of the earth caused by underground movement along a fault line or by volcanic activity.The size of earthquakes is measured using the Richter scale. And the movment and the waves a mesured using a seisimograph (say size-mu-graph). The scale divides the size of earthquakes into categories called magnitudes which are an guess of the energy released by an earthquake.An earthquake comes when the rocks break and move as a result of stresses caused by plate movements.Earthquakes have rocked the world for decades. But what causes it?The earth can be divided into four main layers: the solid inner core, the liquid outer core, the mantle, and the crust. An earthquake is caused by a sudden rupture(the earth's surface) in a fault. A fault is the broken surface within the rocky pile inside the earth's crust. Stress in the earth's outer layer cause a pushing effect against the sides of the fault. .Due to this motion, rocks slip or slide against each other releasing energy. This released energy travels in waves through the earth's crust and causes the shaking that we feel during an earthquake. Read this its about earthquakes.