3.  Earthquakes are caused by a process called faulting. Faulting is a process when tectonic plates covering the earth rub together and create pressure. When the pressure is so great that neither plate can withstand any more pressure, the rocks near the plates break and create a wave. The earthquake is the shaking motion that people feel when two rocks near a tectonic plate break. This is why earthquakes occur mainly where tectonic plates meet. Occasionally, an earthquake is so big, that places very far away from the site of the earthquake can feel the wave, or shaking caused by the earthquake. For example, a seismogram in Germany taken in 1906 had in increase in ground moving because of the 1906 San Francisco earthquake, 9100 kilometers away.

4.  Stress in the earth’s outer layer causes a pushing effect against the sides of a fault. Rocks sometimes slip or collide and it releases a wave effect which causes the shaking feeling during an earthquake. This occurs under the surface of the earth.