EART 2 Lecture Notes - Lecture 12: Hypocenter, Linear Elasticity, Friction
Document Summary
An earthquake is process of sudden, shearing slip on fault (or creation of a new crack) combined with resultant vibrations. Friction depends on pressure, temperature, fluids, slip velocity, fault history, and material properties in the fault zone. Strain accumulates in the volume of rock around the fault called the fault zone. Sliding between the two rock masses is resisted by friction (static friction) When the strain in the rock approaches limiting value of 10x10^-4, you will either break the rock (form a new fault), or overcome frictional resistance of the fault, abruptly releasing stored strain energy. The sudden change in stress/strain in the source volume generates p and s waves that expand outward from the source volume. Much of the energy is consumed in heating of the fault surface as it slides. Plate motion already occurred, earthquakes catch up with movement. Friction builds up, earthquake occurs when friction is overcome.
