PREDICTING STRONG EARTHQUAKE SHAKING USING OCEAN WAVES

Predicting strong ground motion, as the strong shaking in earthquakes is called, from future earthquakes is among the most important research topics in seismology. Typically, seismologists do this through ground motion prediction equations that express relationships between earthquake characteristics and ground motion intensity. There is relatively little data to constrain these relationships, and in particular, there are few records of ground motion close to large earthquakes. As a result, seismologists are increasingly turning to simulations to compensate for this lack of data. Validating the accuracy of these simulations is critically important. In this talk I present a new approach for strong ground motion prediction. It relies on data that is one million times weaker in amplitude than the earthquake shaking of interest. The method uses the ambient seismic field, which is primarily generated by coupling of wave motion in the fluid ocean to wave motion in the solid Earth, to construct "virtual earthquakes" that can be used to predict long-period strong ground motion for scenario earthquakes.

Speaker: Dr. Gregory C. Beroza