Start Date: April 19, 2017 - 04:15 PM
End Date: April 19, 2017 - 05:15 PM
Abstract: I present the theory and practice of supervirtual seismic interferometry (SVI) which transforms noisy seismic data into useful information. In some cases SVI can increase the signal-to-noise (SNR) of arrivals by more than an order of magnitude. Several case histories are used to illustrate the harvesting and inversion of refractions, diffractions, and surface waves from dead data.
1. Noisy ambient noise data recorded next to freeways in Long Beach, California. SVI is applied to the noisy passive data to enhance the SNR of the surface waves. These surface waves are inverted for the S-velocity distribution, which can be used to assess earthquake hazard in the city.
2. Refraction arrivals are resurrected from dead data recorded by a marine survey offshore of Taiwan and by a land survey over Olduvai Gorge, Tanzania. First arrivals out to offsets of more than 100 km are recovered in the marine example, and far-offset SVI refractions in the Tanzania data are inverted to reveal the basement topography in Olduvai Gorge.
3. Diffractions from the core mantle boundary are almost impossible to identify in teleseismic data excited by moderate earthquakes (5.0<M<6.0) where the epicentral distance is greater than 1000 km. This limitation is eliminated by applying SVI to such data.
Ph.D., Columbia University, 1984
M.S., Columbia University, 1982
Professor Schuster's research interests are in seismic imaging, interferometry, waveform inversion, EM methods, seismic field techniques, and the use of novel methods for super resolution imaging. His geophysical lab is equipped with state-of-the-art seismographs for 624 channel recording and a 72-channel resistivity array for both exploration, engineering, and earthquake applications. Schuster has a strong interest in geophysical characterization of archaeological sites.