Earth Sciences 1022A/B Lecture Notes - Lecture 5: Hypocenter, Seismic Wave, Epicenter

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Stephen R Hicock

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: rock bend until they rupture (earthquake), then stress builds up and they start bending again. Foreshocks and aftershocks common with the 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 epicentre. 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. Wave speeds up or slows down crossing the boundary.