Van Tuyl Lecture: David Shelly, USGS
January 31 @ 4:00 pm - 5:00 pm
David Shelly, United States Geological Survey
Topic: Untangling the Web of Fluids and Faulting in Earthquake Swarms
Abstract: Earthquake swarms are common signatures of unrest in both volcanic and tectonic environments. Their interpretation in the broader system depends upon determining the underlying physical processes driving the swarm, which can be difficult. Seismic recordings of earthquakes provide the most direct constraints on active processes in the source region, yet limited resolution of routine processing obscures much of this valuable information. Here, I explore high resolution views of earthquake swarms at Yellowstone and Long Valley Calderas, produced by direct comparisons of millions of pairs of seismic waveforms. This analysis reveal dramatic migration of earthquake activity with time, with complex faulting geometries. In total, these patterns suggest that earthquake swarms result from a complex interaction of aqueous fluid pressure diffusion and faulting in the subsurface.