GEOL107 Lecture Notes - Lecture 18: Richter Magnitude Scale, Seismometer, Epicenter
1 Nov 2018
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Document Summary
Can use difference in velocities or p-waves (faster) and s-waves (slower) to locate where earthquake occurred. Involves use of seismographs to record ground displacements. Measure difference in travel time between arrival of first p-wave (travels faster) and s-wave (travels slower) at a seismograph station. Plot difference in travel time determined in step 1 on standard travel-time vs. distance curve. This determines distance that seismograph station was away from earthquake. Plot distance determined in step 2 as radius away from location of seismograph station. Repeat steps 1-3 at least 2 more times. Where circles drawn from solutions in step 3 intersect denotes location of earthquake epicenter. Most earthquakes occur at boundaries between tectonic plates. Some earthquakes occur at locations that used to be boundaries, or that in the future will become boundaries, between tectonic plates. Measure of physical destruction caused by earthquake. Measure of energy released by earthquake by looking at amplitude of seismic waves.
