OBSERVED SEISMICITY IN THE JACKSON PURCHASE REGION OF WESTERN KENTUCKY BETWEEN JANUARY 2003 and JUNE 2005

ANDERSON, C.E., WOOLERY, E.W., Dept. of Geological Sciences, University of Kentucky, Lexington, KY 40506; and WANG, Z., Kentucky Geological Survey, Lexington, KY 40506, woolery@uky.edu.

Many seismic hazard assessments extend the active faults associated with the New Madrid Seismic Zone into the Jackson Purchase Region of western Kentucky, although this projection has not been conclusively proven. This is one reason that western Kentucky, and the Jackson Purchase Region in particular, has high seismic-hazard estimates. The uncertainty for the northern boundary of the NMSZ is due in large part to the lack of fault surface exposure, as well as low-deformation rates. In order to better constrain the seismotectonic structure and source-zone boundaries, this study's objective is to closely monitor the seismicity for this area of Kentucky. A temporary seismic network of seven, single and 3-component, short-period, seismic stations were deployed in the Jackson Purchase Region since late 2002 with support from the Kentucky Consortium for Energy and the Environment. Five earthquakes with magnitude greater than 2.0 have been recorded by the temporary network between January 2003 and June 2005. The focal depths for these events have ranged between 1.5 and 10 km. We note that the earthquake epicenters appear to concentrate in the area near Bardwell, Kentucky.