HR: 10:30h
AN: U52A-01 INVITED [Abstracts]
TI: Effects of the Mw 9.0 Sumatra Earthquake and Tsunami on Earth's Shape
AU: * Blewitt, G
EM: gblewitt@unr.edu
AF: Nevada Bureau of Mines and Geology, and Nevada Seismological Laboratory, University of Nevada, 1664 N.
Virginia St., MS178, Reno, NV 89557 United States
AU: Plag, H
EM: hpplag@unr.edu
AF: Nevada Bureau of Mines and Geology, and Nevada Seismological Laboratory, University of Nevada, 1664 N.
Virginia St., MS178, Reno, NV 89557 United States
AU: Kreemer, C
EM: kreemer@unr.edu
AF: Nevada Bureau of Mines and Geology, and Nevada Seismological Laboratory, University of Nevada, 1664 N.
Virginia St., MS178, Reno, NV 89557 United States
AU: Hammond, W C
EM: whammond@unr.edu
AF: Nevada Bureau of Mines and Geology, and Nevada Seismological Laboratory, University of Nevada, 1664 N.
Virginia St., MS178, Reno, NV 89557 United States
AU: Titov, V V
EM: vasily.titov@noaa.gov
AF: Tsunami Program, NOAA/PMEL - UW/JISAO, 7600 Sand Point Way NE, Bldg. 3, Seattle, WA 98115-6349 United States
AB:
Global Positioning System (GPS) observations from the global IGS network are used to investigate geodynamic processes induced by the Mw 9.0 Sumatra earthquake and its subsequent tsunami. The earthquake would have induced change in Earth's shape over a broad spatio-temporal spectrum, including strong motion; permanent co-seismic displacement; surface loading due to the
tsunami propagating barotropically through the global ocean; free oscillations of the solid Earth with periods of up to 53
minutes lasting for several days after the initial earthquake; and transient post-seismic deformations lasting from days to
years. Initial model calculations of the co-seismic displacement field predict horizontal displacements of >20 mm in the
near field (up to 1000 km) and >0.1 mm for the entire Earth's surface. Tsunami-induced loading signals are expected to be
of the order of several mm. The free oscillations may have vertical amplitudes of several cm. GPS data are analyzed to
determine the global pattern of the 3-d displacement field induced by the earthquake. GPS-determined time series of 3-d
displacements with high temporal resolution will be analyzed to determine the geometric amplitudes of the free oscillations
and the tsunami load-induced deformations of the earth surface. For the latter, predictions based on modeled sea-level
anomalies will be fitted to the global polyhedron of observed displacements. The ultimate goal is to assess the feasibility
of using the tsunami-induced changes in the Earth's shape as observed by the regional/global GPS network in improving tsunami models and having it incorporated into a tsunami warning system.
DE: 1223 Ocean/Earth/atmosphere interactions (3339)
DE: 1242 Seismic deformations (7205)
DE: 1243 Space geodetic surveys
DE: 4564 Tsunamis and storm surges
SC: Union [U]
MN: 2005 Joint Assembly