1. Analysis of the seismicity in central Tibet based on the SANDWICH network and its tectonic implications.
- Author
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Zhu, Gaohua, Liang, Xiaofeng, Tian, Xiaobo, Yang, Hongfeng, Wu, Chenglong, Duan, Yaohui, Li, Wei, and Zhou, Beibei
- Subjects
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SEISMIC networks , *PLATE tectonics , *FAULT zones , *GEOLOGIC faults - Abstract
We have located a total of 232 local earthquakes using data recorded by the SANDWICH seismic network from November 2013 to October 2014 in central Tibet across the Bangong-Nujiang suture (BNS). The focal depths of all earthquakes are shallower than 30 km and therefore are in the upper crust. The absence of lower crust earthquakes may imply a weak, ductile lower crust in central Tibet. Moreover, these earthquakes are dispersed throughout conjugate strike-slip fault zones, indicating that evenly distributed upper crustal deformation might predominate in central Tibet. This observation agrees with the hypothesis that conjugate fault zones accommodate coeval east-west extension and north-south contraction via continuous deformation. Moreover, the focal mechanisms show that strike-slip and normal faulting are the dominant types of deformation and that the extension in central Tibet is oriented approximately east-west. Despite some anomalies, the kinematics implied by most of the focal mechanisms correlate well with those of the surface structures. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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