HR: 1340h
AN: G13A-0918    [Abstracts]
TI: Long-term post-seismic deformation over Mongolia, a look from InSAR.
AU: Osmanoglu, B
EM: batu@rsmas.miami.edu
AF: University of Miami - RSMAS, 4600 Rickenbaker Causeway, Miami, Fl 33149, United States
AU: * Gourmelen, N
EM: ngourmelen@rsmas.miami.edu
AF: University of Miami - RSMAS, 4600 Rickenbaker Causeway, Miami, Fl 33149, United States
AU: Calais, E
EM: ecalais@purdue.edu
AF: Purdue University, Dept. of Earth & Atmospheric Sciences Purdue University, West Lafayette, IN 47907, United States
AU: Amelung, F
EM: amelung@rsmas.miami.edu
AF: University of Miami - RSMAS, 4600 Rickenbaker Causeway, Miami, Fl 33149, United States
AB: Western Mongolia has been the most seismically active intracontinental region in the world in the past century, with four earthquakes of magnitude 8 and greater since 1905. The Bolnay-Tsetserleg earthquake sequence of 1905, in particular, has released the largest amount of seismic energy ever observed inside a continent. GPS measurements (Calais et al., 2003) and paleoseismology (Ritz et al., 1995) are consistent with deformation being accommodated by left-lateral slip on the three major E-W trending faults slipping at rates still poorly determined, but possibly on the order of 1 to 3 mm/yr. The combination of a recent sequence of large earthquakes and low background interseismic strain accumulation makes Mongolia an ideal target for the study of long-term post-seismic deformation by viscoelastic relaxation and associated stress triggering. Vergnolle et al., [2003] and Pollitz et al., [2003] used GPS results to probe the lithospheric structure in Mongolia and subsequently show that stress trigerring due to viscoelastic relaxation within the earthquake sequence is a likely explanation for the Mongolia cluster sequence. We present new geodetic measurements that significantly improve the spatial resolution of the deformation field in the area of the M8.1 1957 Gobi Altai earthquake. We use satellite data from the ERS1 and ERS2 satellites to produce ground velocity and time series map of the deformation field. In conjunction with existing GPS velocities, the obtained velocity field is used to constrain post-seismic models of viscoelastic strain relaxation.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1236 Rheology of the lithosphere and mantle (7218, 8160)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1242 Seismic cycle related deformations (6924, 7209, 7223, 7230)
DE: 8111 Continental tectonics: strike-slip and transform
SC: Geodesy [G]
MN: 2007 Fall Meeting