Difference between revisions of "Earthquake"
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[[File:Japan quake sendai.jpg|thumb|200px|Japan quake 2011.]] | [[File:Japan quake sendai.jpg|thumb|200px|Japan quake 2011.]] | ||
| − | An '''earthquake''' is when the [[Earth]] shakes, caused by [[plate tectonics|tectonic]] activity in an area after the release of stored [[energy]] from the [[rock]]. Earthquakes most commonly occur on tectonic plate boundaries, and also occur along [[fault|faults]] where previous movement has occurred. There are 500,000 detectable earthquakes in the world each year. | + | An '''earthquake''' is when the [[Earth]] shakes, caused by [[plate tectonics|tectonic]] activity in an area after the release of stored [[energy]] from the [[rock]]. Earthquakes most commonly occur on tectonic plate boundaries, and also occur along [[fault|faults]] where previous movement has occurred. There are currently 500,000 detectable earthquakes in the world each year. |
Earthquakes are a significant natural [[hazard]] to populations living in areas prone to them, and emergency responses to the hazard vary with economic development. The most powerful and destructive earthquakes occur at tectonic plate boundaries like the [[San Andreas Fault]]. | Earthquakes are a significant natural [[hazard]] to populations living in areas prone to them, and emergency responses to the hazard vary with economic development. The most powerful and destructive earthquakes occur at tectonic plate boundaries like the [[San Andreas Fault]]. | ||
Revision as of 15:36, September 21, 2011
An earthquake is when the Earth shakes, caused by tectonic activity in an area after the release of stored energy from the rock. Earthquakes most commonly occur on tectonic plate boundaries, and also occur along faults where previous movement has occurred. There are currently 500,000 detectable earthquakes in the world each year.
Earthquakes are a significant natural hazard to populations living in areas prone to them, and emergency responses to the hazard vary with economic development. The most powerful and destructive earthquakes occur at tectonic plate boundaries like the San Andreas Fault.
The severity of earthquakes is measured using the Moment Magnitude scale, which replaced the Richter scale with the largest quake ever recorded being 9.5 which struck Chile in 1960[1]. The Mercalli scale has also been used to measure earthquakes.
