MAPPING PREDICTED MMI FOR EARTHQUAKES IN THE NORTHEAST U.S. USING AN AUTOMATED GIS

EBEL, J.E., and SMITH, D., Weston Observatory, Department of Geology and Geophysics, Boston College, Weston, MA 02493, ebel@bc.edu , dina.smith.1@bc.edu.

As a precursor to having ShakeMap operating in the Northeast, an automated GIS has been developed using ArcView to produce a map of predicted Modified Mercalli Intensities following an earthquake in the Northeastern U.S. The GIS prompts the user for the event's information: date, time, latitude, longitude, M_b, M_W, and depth. This information is used along with site effects and a ground motion attenuation relationship, using the formulation of Ebel and Wald (Earthquake Spectra, 19, 511-529, 2003), to calculate the ground motions in an area surrounding the earthquake epicenter. The predicted ground motion is then converted to predicted intensity in the area of the earthquake, and a map is produced of the predicted MMI for the earthquake. Currently, the USGS publishes a webpage (http://pasadena.wr.usgs.gov/shake/ne/) where individuals in the Northeast U.S. can report the felt intensity of an earthquake they have experienced. The Community Internet Intensity Maps (CIIM) produced from observer's reports, as seen on the USGS webpage, were used to calibrate the maps produced by this GIS. The goal of this GIS is to quickly produce a map of predicted felt intensities in a short time after an earthquake that can be used by emergency management personnel and staff at Weston Observatory.