119628474 Humphreys This research involves the completion of analysis of results from the Snake River Plain, Idaho, project. This project involved the emplacement and recording of seismic data from 28 PASSCAL portable seismic systems over a 10 month period in 1993-1994 to delineate the upper mantle and crust of the Snake River Plain, a volcanic feature that is the result of the passage of the Yellowstone Hot Spot across the northwestern U.S. The need for additional funds is in part a result of the success of the experiment and the acquisition of much more usable data than was anticipated because of a high success rate for data recording and a high number of usable seismic events during the recording interval. The results will bear on questions of what happens to upper mantle structure and earthquake occurrence when a hot spot traverses through a region of continental crust. This research is a component of the National Earthquake Hazard Reduction Program. ***
