Collaborators: H. Kanamori, S. Krishnan, N. Lapusta; Students/Post Docs: M. Mello and H. Bhat
Directly studying earthquakes presents a host of insurmountable difficulties, the least of which is our inability to trigger earthquakes of various magnitudes at will and the lack of means of scrutinizing the behavior at depth while the quake propagates.
We have developed techniques to produce miniature laboratory earthquakes and follow their progress with high-speed imaging tools. Our quakes mimic actual quakes, and have demonstrated the existence of "super-shear" or "intersonic" rupture speeds. The propagating fronts of such intersonic ruptures feature a Mach-cone of shear shock waves similar to that of supersonic aircraft. This unusual feature produces potentially catastrophic ground shaking signatures (equivalent to sonic booms) with unexpected implications to seismic hazard analysis.
"Intersonic Earthquakes: What Laboratory Earthquakes Teach Us About Real Ones" was presented as part of the Earnest C. Watson Lecture Series on February 17, 2010.
Watch it on iTunes U.