This research is to utilize a theoretical method developed by the Principal Investigator, the partitioned waveform method, to digital and analog seismograms to investigate the S velocity in the upper mantle of the North American plate, with special emphasis on the lithosphere/asthenosphere structure beneath the continent. The major goal of this study will be to provide a structural interpretation of the upper mantle beneath the continents with a resolution of a few hundred km or better that is sufficiently well balanced geographically and that extends deep enough to serve as a framework for the interpretation of gravity anomalies, heat flow and stress patterns, and to study the evolution of the continent.
