Seismic imaging of the Doty Fault, Washington

Geologic evidence supports the existence of the Doty Fault which extends through the Chehalis region in western Washington. Residing in the forearc of the Cascadia subduction zone, seismic hazards pose a major threat to communities within the northwest region, and the major goal of this project is to determine whether the Doty fault is still active by retrieving information about sediment deformation via 2D seismic imaging. From gravity and magnetic constraints, three transects perpendicular to the fault within the sediment basin have been prioritized as the major objectives. Each survey area will consist of active source 2D reflection imaging and multichannel analaysis of surface waves (MASW), passive microtremor array methods (MAM), and 2-3D horizontal-to-vertical spectral ratio (HVSR) imaging.