HR: 08:25h
AN: G51A-02    [PDF]
TI: Measuring Seismic Surface Waves with 1-Hz GPS
AU: * Bilich, A
EM: andria.bilich@colorado.edu
AF: Department of Aerospace Engineering Sciences, University of Colorado at Boulder, UCB 429, Boulder, CO 80309-0429 United States
AU: Larson, K
EM: kristine.larson@colorado.edu
AF: Department of Aerospace Engineering Sciences, University of Colorado at Boulder, UCB 429, Boulder, CO 80309-0429 United States
AU: Dragert, H
EM: dragert@pgc.nrcan.gc.ca
AF: Geological Survey of Canada, Pacific Geoscience Centre, 9860 West Saanich Road, Sidney, BC V8L 4B2 Canada
AU: Bodin, P
EM: bodin@ceri.memphis.edu
AF: Department of Earth Sciences, Center for Earthquake Research and Information, University of Memphis, Memphis, TN 38152 United States
AU: Gomberg, J
EM: gomberg@usgs.gov
AF: United States Geological Survey, 3876 Central Ave., Ste. 2, Memphis, TN 38152-3050 United States
AB: Large earthquakes can cause seismological instrumentation to saturate or `clip', even hundreds to thousands of kilometers away from the epicenter. In cases where seismological instruments fail to record ground motion, high-rate GPS data can serve as a replacement for these missing seismic data. We present an analysis of 1-Hz GPS data collected after the 2002 November 3 M7.9 Denali Fault earthquake. A significant number of seismic instruments clipped during this earthquake. An initial analysis demonstrated that surface waves could be observed on 1-Hz GPS instruments as far away as Colorado Springs, CO. In this study we add data from over 20 GPS receivers recording at 1-Hz in Canada and the western United States. Horizontal displacements exceeded 30 cm at some of these sites. We also investigate techniques for reducing GPS-specific errors. If available, 1-Hz GPS data collected in days before and after the earthquake are used to estimate and remove GPS errors, significantly improving 1-Hz GPS precision. Also, the impact of receiver mixing and ambiguity resolution performance is assessed.
DE: 1242 Seismic deformations (7205)
DE: 1294 Instruments and techniques
DE: 7200 SEISMOLOGY
DE: 7205 Continental crust (1242)
DE: 7212 Earthquake ground motions and engineering
SC: Geodesy [G]
MN: 2003 Fall Meeting