GEOL 303 Lecture Notes - Lecture 16: San Andreas Fault, Carrizo Plain, Hypocenter
Document Summary
April 18, 1906 - one of the largest ca earthquakes in historic times. Centered on the san andreas fault, just north of sf. Many buildings destroyed, but 80% of damage caused by fire. Fires broke out from ruptured gas mains, but water mains also ruptured. Most devastating fire was the ham and eggs fire. Official death count directly from the earthquake was 800. Value is much higher, additional 5000 died as an indirect result. 8. 5 feet of lateral slip along the san andreas fault. Elastic rebound theory - both sides of fault are in slow but constant motion, resulting in bending of rocks near the fault. Stress eventually gives way to fault rupture and rocks when spring back elastically to their original shape during the earthquake. Old idea: two sides move as the result of the earthquake. Elastic rebound - two sides in constant motion, but offset occurs during earthquake. Motion across fault is 6 cm/year (2 in/year)
