Imaging the Upper Crust at Newberry Volcano Using Large-Offset Reflections

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This is an SGER award which will take advantage of dynamite explosions during a previously funded CD project (the High Lava Plains Experiment) to seismically image the magma chamber underneath the Newberry Volcano in central Oregon. Newberry is a large, recently active volcano that is thought to be underlain by a shallow magma chamber. This project will extend the High Lava Plains Experiment by using reflected P and S waves to image a hypothesized crustal magma sill.The PIs will use existing imaging methods and a new experimental technique to image shallow, continental magma systems using large-offset explosive sources. Magma-filled sills, even of limited spatial extent, give rise to large amplitude P and S wave reflections, particularly at low incidence angles. These have been observed in marine seismic data from magma sills at the East Pacific Rise. The project will extend this method to image shallow, continental magma systems. The results of this study will provide a better understanding of the Newberry Volcano magma plumbing system and the relation between magma storage and volcanic processes. Newberry volcano is an excellent target as it was active as recently as 1,300 years ago and seismic tomography by the USGS in the 1980s indicates a shallow crustal magma body.