9628813 Powell This research involves seismic and potential-field investigations to improve resolution of seismogenic crustal features in basement rocks below the Paleozoic thrust sheets in eastern Tennessee. The Eastern Tennessee Seismic Zone (ETSZ) is a pronounced zone of earthquake activity in a region 300 by 50 km with earthquake hypocenters extending from 5 to 25 km in depth. The zone produces the second highest release of seismic strain energy east of the Rocky Mountains and is unique in that it is associated with regional-scale potential-field (gravity and magnetic) anomalies. Seismic recording of quarry blasts will be done to test the feasibility of this technique for the study of crustal structure. Concurrently, analysis and inversion of existing potential field data will be done. Seismic and potential-field data analysis will be integrated to provide a better understanding of structures responsible for earthquakes within the region and outline the best approach for further efforts. This research is a component of the National Earthquake Hazard Reduction Program. ***
