Earthquakes
![Picture](/uploads/1/7/5/1/17518761/7110373_orig.jpg)
An earthquake is the shaking of the ground due to the movement of tectonic plates. Most earthquakes take place near the edges of tectonic plates. Tectonic plates are giant pieces of Earth's thin, outermost layer. They move around on top of a layer of plastic rock. As a result of these movements, numerous faults are created in the Earth's crust. A fault is a break in the Earth's crust along which blocks of the crust slide relative to one another. An example of a fault is the San Andreas Fault located in California. Earthquakes occur along faults because of this sliding. Also, earthquakes can happen both near Earth's surface or far below it. Sometimes, earthquakes happen along faults in the middle of tectonic plates. Earthquakes can occur in various places. (Holt Science and Technology Earth Science Pages 224-227) (Picture above was found at http://www.astro.virginia.edu/class/oconnell/astr121/guide12-s02.html)