Modeling Crust of Columbia River Basalts Using Ambient Noise Recordings

Mackenzie R. Wooten, Jorge A. Castillo Castellanos, & Robert W. Clayton

Submitted August 14, 2018, SCEC Contribution #8534, 2018 SCEC Annual Meeting Poster #104

Flood-basalt eruptions are the Earth’s largest volcanic events and are thought to have caused massive extinction events. These events take part in the formation of hotspots and produce lavas that have covered much of the Earth’s surface. The dynamics of these events have yet to be resolved however. One of the most recent flood basalt eruption, the Columbia River Basalts (CRB), is the site of volcanic propagation from the Yellowstone hotspot. The CRB shows evidence of a reconstructed crust and large crustal magma chamber, possibly due to the foundering and sinking of large portions of the lithosphere into the asthenosphere, which controlled the flow and distribution of volcanism in the area. In this study, we use two years of ambient noise recordings from a 60-station line array stretching from northern Oregon to southern Washington to solve for the shear wave velocity structure beneath this region. In addition, we use the difference between horizontally and vertically polarized shear wave velocities along this experiment to quantify radial anisotropy and illuminate any structural fabric that might be related with the areal extent of a large magma chamber in the lithosphere and the existence of a descending pluton beneath it.

Wooten, M. R., Castillo Castellanos, J. A., & Clayton, R. W. (2018, 08). Modeling Crust of Columbia River Basalts Using Ambient Noise Recordings. Poster Presentation at 2018 SCEC Annual Meeting.

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