HR: 1340h
AN: G13B-1235    [Abstracts]
TI: High-Rate GPS Data - When are They Useful?
AU: Clinton, J F
EM: jclinton@sed.ethz.ch
AF: ETH Zurich, Swiss Seismological Service (SED), Department of Geophysics, ETH Zurich, Zurich, 8093, Switzerland
AU: * Larson, K
EM: kristinem.larson@gmail.com
AF: University of Colorado at Boulder, Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO 80309, United States
AU: Bilich, A
EM: Andria.Bilich@noaa.gov
AF: National Geodectic Survey / NOS NOAA, Geosciences Research Division National Geodetic Surcey / NOS / NOAA 325 Broadway St. E/GC2, Boulder, CO 80305, United States
AB: High-rate GPS signals have recently been shown to clearly record measurable displacements at long periods from teleseismic and regional distances from large earthquakes (e.g. 2002 Mw7.9 Denali and 2003 Mw8.3 Tokachi-Oki) and at shorter periods from moderate earthquakes (2003 Mw6.5 San Simeon and 2004 Mw6.0 Parkfield). The ability to directly record broadband displacement - including static offsets - without sensitivity to tilting and without the risk of clipping, means high-rate GPS data are an ideal compliment to existing strong motion networks for recording near-source and regional ground motions. This is especially the case near subduction zone regions where major events with significant displacements and rotations over a wide area are expected. Current high-rate GPS processing provides accuracy of 5-10 mm (depending on the component) at periods less than 5 minutes. It is not clear what limitation this minimum signal resolution should have on the deployment of future high-rate GPS stations and archival of the high-rate data. Should high-rate GPS capability be included within GPS networks only near major faults, and should the high-rate data be continuously archived and processed, or only triggered during large events? This study looks at event and noise signals from 1sps GPS stations which recorded the Parkfield, Denali, San Simeon, and Tokachi-Oki events. We provide an estimation of the background noise across a broad frequency spectrum, from 0.5Hz to 1000s. We compare the GPS noise estimates with previous seismic studies of noise and event signals in terms of acceleration, velocity and displacement.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 7212 Earthquake ground motions and engineering seismology
DE: 7294 Seismic instruments and networks (0935, 3025)
SC: Geodesy [G]
MN: 2007 Fall Meeting