GEOL 1014 Chapter Notes - Chapter 6: Elastic-Rebound Theory, Seismic Wave, Directivity
Document Summary
An earthquake is just a release of energy via vibrations. Focus: where an earthquake originated under the earth. Epicenter: where the earthquake took place on the surface. Each magnitude up is 30x more powerful than the previous magnitude. Seismic waves travel differently through different rock materials. Material amplification: intensity (amplitude of vertical movement) of ground shaking more severe in unconsolidated materials. Seismic energy attenuated more and propagated less distance in unconsolidated materials. Directivity: another amplification effect, the intensity of seismic shaking increases in the direction of the fault rupture. In the mojave desert an earthquake would travel less distance than in oklahoma. Ground motion is related to the amplitude of seismic waves and its accelerations. Measured by acidometers in terms of the acceleration of gravity. Inactive and aftershock stage: stress accumulation state, foreshocks, main shock (major earthquake) Dilatancy-diffusion model: the fault valve mechanism hypothesizes that fluid pressure rises until failure occurs thus triggering an earthquake.
