HR: 1340h
AN: T13B-1331    [Abstracts]
TI: Seismic anisotropy of upper mantle in the northeastern margin of the Tibetan Plateau
AU: Chang, L
EM: Changlijun@eyou.com
AF: Institute of Geophysics, China Earthquake Administration, No 5 Minzuxueyuan South Road, Haidian District, Beijing, 100081, China
AU: * Wang, C
EM: wangcy@cdsn.org.cn
AF: Institute of Geophysics, China Earthquake Administration, No 5 Minzuxueyuan South Road, Haidian District, Beijing, 100081, China
AU: Ding, Z
EM: zhfding@vip.sina.com
AF: Institute of Geophysics, China Earthquake Administration, No 5 Minzuxueyuan South Road, Haidian District, Beijing, 100081, China
AB: By using the polarization analysis of teleseismic SKS waveform data recorded at 30 seismic stations which involved in the digital seismograph network of the northeastern margin of the Tibetan Plateau, we obtained the SKS fast-wave direction and the delay time between fast and slow waves of each station by use of the stacking analysis method, and finally acquired the fine image of upper mantle anisotropy in the northeastern margin of the Tibetan Plateau. From the results, the fast-wave polarization direction is basically NW direction and clockwise rotation trend. The delay times vary from 0.70 to 1.51s in the study region.The fast-wave polarization direction is consistent with the strike of the major faults in the observed region. The characteristics of the fast-wave direction is similar to the trends of the minimum average principal compressional stress directions in the northeast margin of the Tibetan Plateau and to the trends of GPS observation results. Research shows that the regional tectonic stress field resulted in upper mantle material clockwise rotational deformation and flow, and make the alignment of upper mantle peridotite lattice is parallel to the direction of material deformation. The upper mantle is vertically coupled with the crust.
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8138 Lithospheric flexure
DE: 8160 Rheology: general (1236, 8032)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting