This experiment is the land portion of a seismic reflection- refraction survey across the Oregon continent-ocean transition zone which piggybacks on an already-scheduled seismic reflection survey. The objective is to obtain a 2-D image of the velocity structure of the subducting oceanic crust and overlying material from the toe of the accretionary wedge arcward to beneath the Coast Ranges. The structure of both the offshore portion of the Juan de Fuca plate and the western portion of the accretionary wedge are key to an understanding of the tectonic framework of the Pacific Northwest. This research deals with the definition of the tectonics of an area identified as a candidate for a major subduction-type earthquake and therefore is an important contribution to the National Earthquake Hazard Reduction Program.
