HR: 14:55h
AN: G13A-05    [Abstracts]
TI: A Canadian Pilot Project for a GPS-Augmented Tsunami Warning System
AU: * Dragert, H
EM: hdragert@nrcan.gc.ca
AF: Geological Survey of Canada, Pacific Geoscience Centre 9860 West Saanich Road, Sidney, BC V8L 4B2 Canada
AU: Schmidt, M
EM: mschmidt@nrcan.gc.ca
AF: Geological Survey of Canada, Pacific Geoscience Centre 9860 West Saanich Road, Sidney, BC V8L 4B2 Canada
AU: Wang, K
EM: kwang@nrcan.gc.ca
AF: Geological Survey of Canada, Pacific Geoscience Centre 9860 West Saanich Road, Sidney, BC V8L 4B2 Canada
AU: Bock, Y
EM: ybock@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive IGPP 4208, La Jolla, CA 92093-0225 United States
AB: Whether a tsunami has been generated from a large earthquake immediately offshore cannot be determined within a crucial time window from seismic or tide gauge data alone. Geological and geodetic data show that coseismic motions of the Earth's surface even hundreds of kilometers from the fault can be used to determine the nature of the rupture and whether the earthquake is tsunamigenic. High-rate (1 sps or greater), totally autonomous GPS stations located along the coast can provide on-line streamed data that can be analyzed in real time to provide an update of relative positions to an accuracy of 1-2 cm horizontally and 3-5 cm vertically with a latency of a few seconds. Regional ground displacements along the coast at the time of a major offshore earthquake could therefore point to the certainty of a tsunami within less than a minute. The Geological Survey of Canada is currently setting up a prototype network to facilitate real-time positioning along the coast of the Canadian segment of the Cascadia subduction zone. The aim is to evaluate the realizability and effectiveness of automatically determining major vertical and horizontal motion at coastal versus inland GPS stations that would unambiguously and rapidly indicate tsunami generation. A network of GPS receivers purchased by the Canadian Hydrographic Service is currently being deployed at geodetic quality installations with continuous on-line communications. As part of this system, we are implementing real-time GPS technology previously applied to seismic (Bock et al., 2004; Langbein and Bock, 2004; Yamagiwa et al., 2004) and volcanic (Mattia et al., 2004) monitoring applications. The target date to have a prototype system operating is December 2005. It is hoped that this relatively low cost technique can become a mainstream tool of tsunami warning systems worldwide.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 4564 Tsunamis and storm surges
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Geodesy [G]
MN: Fall Meeting 2005