High-Resolution Seismic Imaging Investigations of Earthquake Hazards in the United States

The Doty fault is one of several known Quaternary-age fault systems in southwestern Washington State that likely pose a significant seismic hazard to communities in the Puget Lowland including Olympia and Tacoma. The Doty fault has been proximally mapped at the surface, but significant controversy exists about its rate of activity, its structural style (i.e., primarily strike-slip or thrust), its along-strike length, and its overall subsurface deformational footprint. To better characterize this fault system, GHSC will be acquiring high-resolution seismic reflection data at selected sites along the length of the Doty fault in FY2017. Because the bedrock depth in adjacent sedimentary basins is typically less than 500 m, with a total required depth of investigation less than 1 km, the optimal seismic source for this investigation is a trailer-mounted minivib I seismic source, which can be operated in the rural-to-suburban environment of the study area very efficiently. The seismological source characteristics of the minivibI are also deemed to be ideal for the anticipated depth of investigation. GHSC currently does not own such a seismic source. As a research professor at the University of Kentucky, Edward Woolery is an internationally recognized expert on high-resolution seismic reflection imaging of the shallow subsurface. As a principal investigator who has worked collaboratively with USGS researchers on earthquake hazards investigations in the central United States, Professor Woolery has extensive technical knowledge and unique equipment including a IVI T7000 minvib I trailer-mounted seismic source optimally designed for shallow fault zone studies.