TY - JOUR
T1 - Internal Deformation of Lithosphere Beneath Central Tibet
AU - Zhang, Heng
AU - Zhao, Dapeng
AU - Zhao, Junmeng
AU - Hu, Zhaoguo
N1 - Funding Information:
This research was supported by the National Natural Science Foundation of China (grants 41776201 and 41404079), Major Program of National Natural Science Foundation of China (grant 41490611), the External Cooperation Program of BIC, Chinese Academy of Sciences (grant 131551KYSB20150009), and the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (grant XDB03010702). We thank the organizers of the Hi-CLIMB project for sharing the original seismic data (http://www.fdsn.org/networks/ detail/XF_2002/). The facilities of IRIS Data Services, and specifically the IRIS Data Management Center, were used for access to waveforms, related metadata, and/or derived products used in this study. The IRIS Data Services are funded through the Seismological Facilities for the Advancement of Geoscience and EarthScope (SAGE) Proposal of the U.S. National Science Foundation under Cooperative Agreement EAR-1261681. We thank the JGR Editors, Paul Tregoning and Martha Savage, and two reviewers for their constructive review comments and suggestions. We are grateful to Chunquan Yu for helpful discussions on the layered lithosphere and for providing his Crazyseismic software (Yu et al., 2017) that was used to collect the phase data. The Generic Mapping Tools (Wessel & Smith, 1995) is used to plot the figures.
Publisher Copyright:
©2017. American Geophysical Union. All Rights Reserved.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017/9
Y1 - 2017/9
N2 - We use a large number of high-quality P wave arrival time data recorded by the Hi-CLIMB project to determine a 3-D model of azimuthal anisotropy tomography beneath central Tibet. In the Himalayan block, variations of fast velocity orientation (FVO) are revealed from the crust to the upper mantle. In contrast, the FVO in the Lhasa block exhibits only a slight difference between the lower crust and upper mantle, reflecting a coherent deformation there. Different FVOs are revealed near the Bangong-Nujiang suture, which may reflect anisotropies in different parts of the underthrusting Indian plate. In the upper mantle beneath the Qiangtang block, a strong anisotropy is revealed in the shallower part, whereas a weak anisotropy appears in the deeper part, suggesting that a two-layer anisotropy model is applicable there. A layered lithosphere is detected in the eastern part of the Lhasa block, whereas a consistent FVO is revealed in its western part. Our results indicate that strong deformation has occurred in both the Indian and Eurasian lithospheres.
AB - We use a large number of high-quality P wave arrival time data recorded by the Hi-CLIMB project to determine a 3-D model of azimuthal anisotropy tomography beneath central Tibet. In the Himalayan block, variations of fast velocity orientation (FVO) are revealed from the crust to the upper mantle. In contrast, the FVO in the Lhasa block exhibits only a slight difference between the lower crust and upper mantle, reflecting a coherent deformation there. Different FVOs are revealed near the Bangong-Nujiang suture, which may reflect anisotropies in different parts of the underthrusting Indian plate. In the upper mantle beneath the Qiangtang block, a strong anisotropy is revealed in the shallower part, whereas a weak anisotropy appears in the deeper part, suggesting that a two-layer anisotropy model is applicable there. A layered lithosphere is detected in the eastern part of the Lhasa block, whereas a consistent FVO is revealed in its western part. Our results indicate that strong deformation has occurred in both the Indian and Eurasian lithospheres.
KW - Tibetan Plateau
KW - anisotropy tomography
KW - coherent deformation
KW - lithosphere
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U2 - 10.1002/2017JB014184
DO - 10.1002/2017JB014184
M3 - Article
AN - SCOPUS:85031037322
VL - 122
SP - 7329
EP - 7342
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
SN - 2169-9313
IS - 9
ER -