GEOLOGY 1 Lecture Notes - Lecture 29: Mercalli Intensity Scale, East Los Angeles College, Richter Magnitude Scale
Document Summary
Stress: a force exerted per unit area within rocks. Strain: deformation (size shape and orientation) of rocks caused by stress. Rock strength: rock"s ability to withstand a level of stress before rupture. Focus: the point at depth where the rocks ruptured to produce the earthquake. Epicenter: the location on the surface of earth above the focus. Richter scale: related to the amplitude of ground motion. An increase of one order in magnitude= a tenfold increase in amplitude. Measuring the amount of strain energy released. Based on the amount off faukt displacement. Most earthquakes are concentrated along plate boundaries (interpolate boundaries), nearly all catastrophic earthquakes are shallow earthquakes. Intraplate earthquakes: earthquakes occur within the plate, away from plate boundaries. The e us are generally more damaging due to stronger rocks that transmit earthquake waves more efficiently than rocks in the west. Nearly destroyed the town of new madrid.
