Geography 2152F/G Final: Final Exam Notes
27 Apr 2013
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Document Summary
They result from the rupture of rocks along a fault. Energy from an earthquake is released in the form of seismic waves. They are mapped according to the epicenter; the focus is located directly below the epicenter. They are measured by seismographs and compared by magnitude. The magnitude of an earthquake is expressed as a number to one decimal place. This type of measurement was first developed by richter in 1935. The richter scale was a measure of the strength of a wave at a distance of 100 km from the epicenter. Since then, more accurate methods have been developed and the richter scale is no longer in use. Today, earthquakes are measured using the moment magnitude scale (m). The scale is determined by: the area ruptured along a fault, the amount of movement along the fault, the elasticity of the crust at the focus. Similar to the richter scale, it is a logarithmic scale.
