Where and how do earthquakes occur?

Question

i can't find any worksheets telling me this and I need it to study for my exam.

Thanks in advance :)

Answer 1

Try to down load my power point presentation .Or you can read my answers given to several person on various question in yahoo.You can just type A.Ganapathy.India in google and read my answers.

http://www.mediafire.com/?1bbdzzdml1e

Answer 2

Most earthquakes are produced by the rapid release of elastic energy stored in rock that has been subjected to great forces. When the strength of the rock is exceeded, it suddenly breaks, causing the vibrations of an earthquake. Earthquakes most often happen along existing faults; they occur when frictional forces on the fault surfaces are overcome, such as San Andreas Fault in Calif.

Answer 3

I read the reason earthquakes happen is because of tectonic plates (giant things under the earth that move and things like that) that are shifting underground bump into each other and move. I suggest looking this up on google if you have time to ask the users of Yahoo! Answers.

Hope I helped!

~Liza :-)

Answer 4

Stress that causes earthquakes is created by movement of almost rigid plates that fit together and make up the outer shell of the Earth. These plates "float" on a dense, more fluid layer just beneath them. The plates move at such a slow rate, about the same as a fingernail grows, that we do not notice it in our everyday lives. For instance, the Juan de Fuca plate off the coast of B.C. moves only about 4-5 cm/year relative to the North American plate. Over time, however, this small movement can build up enough stress to produce significant earthquakes.

Earthquakes occur most frequently on, or near, the edges of plates where stress is most concentrated

Answer 5

Earthquakes occur along plate boundaries and they occur in Northern India, Nepal and Southern China where the Himalayian Mountains are. They also occur in California along the San Andrea's fault.

An earthquake is a phenomenon that results from and is powered by the sudden release of stored energy in the crust that propagates seismic waves. At the Earth's surface, earthquakes may manifest themselves by a shaking or displacement of the ground and sometimes tsunamis, which may lead to loss of life and destruction of property.

Earthquakes may occur naturally or as a result of human activities. In its most generic sense, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic waves.

Types of earthquakes Naturally occurring earthquakes Most naturally occurring earthquakes are related to the tectonic nature of the Earth. Such earthquakes are called tectonic earthquakes. The Earth's lithosphere is a patchwork of plates in slow but constant motion caused by the heat in the Earth's mantle and core. Plate boundaries grind past each other, creating frictional stress. When the frictional stress exceeds a critical value, called local strength, a sudden failure occurs. The boundary of tectonic plates along which failure occurs is called the fault plane. When the failure at the fault plane results in a violent displacement of the Earth's crust, the elastic strain energy is released and seismic waves are radiated, thus causing an earthquake. This processes of strain, stress, and failure is referred to as the Elastic-rebound theory. It is estimated that only 10 percent or less of an earthquake's total energy is radiated as seismic energy. Most of the earthquake's energy is used to power the earthquake fracture growth and is converted into heat. Therefore, earthquakes lower the Earth's available potential energy, though these losses are negligible Earthquakes occurring at boundaries of tectonic plates are called interplate earthquakes, while the less frequent events that occur in the interior of the lithospheric plates are called intraplate earthquakes.