The thickness, high internal reflectivity, and low Bouguer gravity signatures likely indicate that this subcreted material is composed of dominantly (meta)sedimentary material that has been emplaced through successive subcretion events over geologic timescales. In the northern and southern portions of the forearc, this “subcreted” material is also characterized by thick (~10 km) anomalously low shear-wave velocity zones.

Our recent seismic images suggest that zones of basal accretion of material from the downgoing plate to the overriding plate may link the seismogenic, geological, and morphological expression of subduction in Cascadia. Both the overriding and downgoing plate have been invoked to play the dominant role in controlling along-strike correlations between seismogenic behavior, potential field measurements, morphological/tectonic characteristics, and seismic structure however, significant feedbacks likely exist between the two. Title: Linking heterogeneous expressions of subduction along the Cascadia marginĪbstract: Spatial correlations between lateral heterogeneity in geophysical, seismogenic, and tectonic features is observed along the Cascadia margin. Speaker: Jonathan Delph, Assistant Professor, Department of Earth, Atmospheric and Planetary Sciences, Purdue University

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