Earth Sciences 1022A/B Lecture Notes - Lecture 10: Epicenter, Hypocenter, Seismic Wave
20 Oct 2016
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Document Summary
Slippage along a fault in the crust at the hypocenter. Occurs below the spot plotted on a map called the epicenter. Elastic rebound: rocks bend until they rupture(earthquake), then stress builds up and they start bending again. Foreshocks and aftershocks common with main event. Body waves: travel through rock: compressional (like slinky toy), primary(p), faster, shear (starts with up and down motion), secondary(s), slower. Record p, s wave arrival times, time difference on time-travel curves gives the distance from the station to the epicenter. Plot distances from at least 3 stations as arcs; 3 arcs intersect at the epicenter. Richter scale: based on energy released by the earthquake. Each number 10 times largest wave amplitude or ~32 times the energy of the last number. At material boundaries part of a seismic wave is reflected, part refracted. Wave speeds up or slows down crossing boundary.
