Methods of Improving Regional Seismic Event Locations
Abstract
In this paper we investigate the effect that depth-dependent Source Specific Station Corrections (SSSC's) have on improving regional seismic event location accuracy. To accomplish this we have relocated events considered GT5 or less that occur within the region encompassed by Weston Geophysical's regional 3-D model of the India-Pakistan region (WINPAK3D) using different depth-dependent SSSC's. By comparing the hypocenters produced using SSSC's at different depths to the ground truth location, we have gained insight into the minimum number of depth-dependent SSSC's that must be implemented in current automatic processing routines for accurate and efficient regional event location. For a crustal earthquake, we generated SSSC's for a suite of depths by calculating travel times for WINPAK3D relative to the global IASPEI91 model (Kennett and Engdahl, 1991) to all regional stations. We then estimated the event hypocenter using the International Seismological Center (ISC) location as an initial hypocenter and two different but closely related methods of SSSC application and hypocenter location. For both location procedures, we compared the location derived from application of the different depth-dependent SSSC's to the ISC location in order to determine if there were significant differences in the hypocenters. Our initial results suggest that two SSSC's, one for the crust and one for the mantle, may be the minimum number of SSSC's to achieve the current goal in location accuracy in our study region.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2001
- Accession Number
- ADA529650
Entities
People
- Carolynn Vincent
- Delaine Reiter
- Michelle Johnson
- William Rodi