Earthquakes as a Nonlinear Dynamical Process

Tuesday, September 25, 2001 - 11:00am - 12:00pm
Keller 3-180
William Newman (University of California, Los Angeles)
Nonlinear processes dominate seismicity and, to complicate matters, we do not have first-principle equations that describe the behavior. While atmospheric scientists have the Navier Stokes equation to work with, solid earth geophysicists do not have---nor will ever have---an equivalent set of equations that describe, for example, the Sierra Nevadas. The laws of fracture mechanics, for example, are phenomenological. Nevertheless, we see many forms of universal behavior---nature seems to be unconcerned with the geologic details, but adheres to scaling laws independent of rheology, geology, geometry, the weather, Congress, .... I will propose how the application of geophysical intuition into these problems can facilitate the developmeant of robust phenomenological models that can provide some important insights into these complex problems. In this lecture, I will review a number of nonlinear dynamical themes and resulting models that have helped improve our understanding of the complexity present in seismic processes.