EARTHQUAKES term papers and essays pg.5

When energy is released from the Earth's crust in a sudden burst, this is known as an earthquake. The size and type of the earthquake is measured by a seismometer, and two common scales - the moment magnitude and the Richter scale - are used to report earthquakes. Earthquake facts show that tremors below a magnitude of 3 usually cause no damage, while those over seven cause serious damage. Recent earthquakes around the globe have caused extensive loss to life and property, including the 2011 9.0 magnitude earthquake in Japan which affected the country's nuclear power stations and the 2004 Indian Ocean earthquake and subsequent tsunami which caused the death of 230,000 people in fourteen countries. Some areas are more prone to earthquakes than others due to their geographical locations. Earthquakes in California, for example, are particularly common as the state sits on the San Andreas Fault which causes a lot of movement in the area. The general effects of earthquakes include the shaking and rupture of the ground, landslides and avalanches, fires, soil liquefaction, tsunamis, flood, injuries and death. Seismologists use many techniques to predict earthquake frequencies and warning systems have been placed in areas which are more prone than others to be hit by a quake.