Earthquakes

Earthquakes happen when two plates under the crust rub against eachother after a while of doing this they stick but still continue to push eachother. After a while the plates will break from all the pressure and cause an earthquake. break causing the ground to shake. Earthquakes occur all over the planet so you can not hide from an earhquake. Also earthquakes that happen under the ocean floor causes tsunamis. The focus is the spot under ground when the plates break. The epicenter is the place on top of the focus above ground. Also the focal depth is the distance from the earth's surface to the focus. That is some imformation about earthquakes.


http://www.geo.mtu.edu/upseis/why.html