GG231 Chapter 3: Earthquakes
Document Summary
Result from a rupture along a fault (crack in the earths crust: rocks on each side move suddenly are release energy as seismic waves. Epicentre point on surface of earth directly above fault rupture. Focus (hypocentre) location of initial rupture along the fault, directly below epic center. Magnitude amount of energy an earthquake releases. Earthquake intensity produces measure of the effects of the earthquake on people and structures. Richter scale kiyoo wadati (japanese seismologist) devised first quantitative magnitude scale, Charles f richter further developed it: quantified the magnitude of local earthquakes as the logarithm to the base of 10, term no longer used by seismologists. Body wave scale (mb) based on strength of type of earthquake that travels through the earth: used to measure magnitude of deep earthquakes. Surface wave scale (ms) based on earthquake waves that travel along ea(cid:396)th"s surface. Except for very large quakes, the richter scale is = to moment magnitude.
