HR: 10:35h
AN: T22D-02    [Abstracts]
TI: Strong crust-mantle coupling at Ordos plateau in North China inferred from shear-wave splitting observations of three seismic arrays at its boundary
AU: * Fu, Y
EM: fuyy@mail.geophy.pku.edu.cn
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Chen, Y J
EM: johnyc@pku.edu.cn
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Li, A
EM: ali2@uh.edu
AF: Geosciences Department, University of Houston, Houston, 77204, United States
AU: Zhou, S
EM: zsy@pku.edu.cn
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Ning, J
EM: njy@pku.edu.cn
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Feng, Y
EM: fyg@pku.edu.cn
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Tang, Y
EM: tangxingong@163.com
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Jin, G
EM: jinwar@gmail.com
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Liang, X
EM: airwolf@163.com
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Jiang, M
EM: jiangmm@pku.edu.cn
AF: Department of Geophysics,School of Earth and Space Sciences, Peking University, Beijing, 100871, China
AU: Sandvol, E
EM: sandvole@missouri.edu
AF: Department of Geological Sciences, University of Missouri-Columbia, Columbia, 65211, United States
AU: Liu, M
EM: lium@missouri.edu
AF: Department of Geological Sciences, University of Missouri-Columbia, Columbia, 65211, United States
AB: Since September 2005, three temporary seismic linear arrays consisting of total 49 portable seismic stations were deployed across the boundary of the Ordos plateau at three locations with different time periods to image the crustal and upper mantle structure of the seismically active fault zones that bound the Ordos plateau, which is a relatively stable block in North China. In this study we focus on the shear-wave splitting data of these temporary seismic arrays to obtain information of the horizontal mantle anisotropy directions at the boundaries of the Ordos plateau. About two-years data of these temporary stations plus several nearby permanent stations were analyzed for shear-wave splitting of both the SKS and the SKKS phases. Because of the relatively dense station spacing (~10 km) of these linear arrays, the data offer good lateral resolution of mantle anisotropy across the plateau boundary. Preliminary results reveal that the fast polarization direction and delay time are not significantly affected by the plateau boundary at the Weihe graben (south boundary) and Sanxi graben (east boundary). In particular fast directions are almost NW-SE trending for all the stations. The uniform fast direction of the mantle anisotropy agrees well with the surface deformation directions inferred from both GPS data and observations of Quaternary fault slip rate, which implies strong crust-mantle coupling at Ordos plateau and its adjacent regions.
DE: 7218 Lithosphere (1236)
DE: 8103 Continental cratons
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8178 Tectonics and magmatism
SC: Tectonophysics [T]
MN: 2007 Fall Meeting