EARTH121 Chapter Notes - Chapter 10: Crystal, Subsidence, Logarithmic Scale
2 Sep 2016
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Document Summary
Earthquake vibration of earth produced by the rapid release of energy. Most often caused by slippage along faults in earth"s crust. Focus source which energy is radiated in all directions: energy dissipates rapidly with increasing distance from the focus, which can be located with sensitive instruments all around the world. Earthquakes associated with plate boundaries occur along faults. Earthquakes are continuous so that as soon as one is over, the continuous motion of plates resumes, adding stress to the rocks until they fail again. Tectonic forces slowly deform rocks on both sides of the fault so that rocks bend and store elastic energy. Eventually, frictional resistance holding rocks together is overcome: slippage occurs at weakest point (focus) and additional slippage occurs occurs until most of the built of stress is released. Elastic rebound slippage allows rock to snap back and rock elastically returns to original shape.
