HR: 0800h
AN: S11B-1022    [Abstracts]
TI: Can Earthquake Location Be Improved in Western China?
AU: * Stork, A L
EM: annas@earth.ox.ac.uk
AF: Department of Earth Sciences, University of Oxford, Parks Rd, Oxford, OX1 3PR United Kingdom
AU: Douglas, A
EM: alan@blacknest.gov.uk
AF: AWE Blacknest, Brimpton, Reading, RG7 4RS United Kingdom
AB: Errors in P travel-time tables (and hence Earth models) can introduce systematic bias into epicentre estimates. Here station corrections estimated for underground explosions at the Chinese nuclear test site are used to relocate earthquakes around the site. This results in a significant reduction in the variance of the residuals (the differences between observed and predicted times) for earthquakes within 250\,km of the test site, confirming, as hoped, that corrections estimated from the explosion times are valid for earthquakes. The application of known station corrections is unsuccessful at reducing the error if variance in the station corrections across the network is low or if one or more recordings has low signal-to-noise ratio resulting in large measurement errors. The maximum effective distance of the corrections from the site is now under investigation. The results should show how rapidly changes in crust and upper-mantle structure affect travel-times at increasing distances from the test site.
DE: 7219 Nuclear explosion seismology
DE: 7299 General or miscellaneous
DE: 7200 SEISMOLOGY
DE: 7203 Body wave propagation
SC: Seismology [S]
MN: 2004 AGU Fall Meeting