HR: 0800h
AN: G21A-0137 [Abstracts]
TI: Measuring Short Term Transient Regional Deformation With High-Frequency GPS Network
Positioning
AU: * Genrich, J
EM: jeff@gpsmail.ucsd.edu
AF: IGPP,
Scripps Institution of Oceanography, MS 0225, T31,
9500 Gilman Dr., La Jolla, CA 92093-0225
United States
AU: Bock, Y
EM: ybock@ucsd.edu
AF: IGPP,
Scripps Institution of Oceanography, MS 0225, T31,
9500 Gilman Dr., La Jolla, CA 92093-0225
United States
AU: Offield, G
EM: goffield@ucsd.edu
AF: IGPP,
Scripps Institution of Oceanography, MS 0225, T31,
9500 Gilman Dr., La Jolla, CA 92093-0225
United States
AU: Vernon, F
EM: flvernon@ucsd.edu
AF: IGPP,
Scripps Institution of Oceanography, MS 0225, T31,
9500 Gilman Dr., La Jolla, CA 92093-0225
United States
AB:
Advances in GPS receiver technology now permit geodetic data sampling at very high rates. A time series analysis of
instantaneously (epoch-by-epoch) computed components of baselines recently measured at 10 and 20 Hz shows near white noise
characteristics for frequencies above 0.5 Hz. It suggests that the same spatial accuracies obtained for 1 Hz sampling of
strong motion surface displacement could be obtained with a much finer temporal resolution. Furthermore, temporospatial
resolution of short-term transient signals (such as coseismic motion and slow earthquakes) and their detection threshold
could be significantly improved by suitably filtered position fixes from high-rate sampled GPS geodetic networks.
Zero-baseline tests indicate that receiver noise significantly contributes to the high frequency spectrum. Below 0.5 Hz,
spectral energy increases exponentially with decreasing frequency until becoming again frequency independent at periods of
several hours.
Upgrading dense GPS geodetic networks in seismogenic areas to high rate sampling and data streaming will thus provide a tool
to constrain source parameters, examine propagation characteristics, and assess local site response of strong motion events.
DE: 9350 North America
DE: 8155 Plate motions--general
DE: 7212 Earthquake ground motions and engineering
DE: 1243 Space geodetic surveys
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting