Greater Insight Into Earthquake Cycles

For those who study earthquakes, one major challenge has been trying to understand all the physics of a fault — both during an earthquake and at times of “rest” — in order to know more about how a particular region may behave in the future. Now, researchers at the California Institute of Technology (Caltech) have developed the first computer model of an earthquake-producing fault segment that reproduces, in a single physical framework, the available observations of both the fault’s seismic (fast) and aseismic (slow) behavior.

This image shows an array of geodetic instruments at the surface of Earth and activity that was modeled on the fault below. The yellow colors indicate the highest speeds of slippage between plates along the San Andreas Fault. The reddish colors represent slower seismic speeds and the bluish colors indicate slippage at velocity close to the long-term advance of the San Andreas Fault. The dark color indicates a portion of the fault where the velocity is so small that it appears completely locked. (Credit: Sylvain Barbot / Caltech)