Focal depth estimates of earthquakes in the Himalayan-Tibetan region from teleseismic waveform modeling
Ling Bai1, 2, Jeroen Ritsema2, Junmeng Zhao1
1 Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China 2 Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor MI 48109, USA
Focal depth estimates of earthquakes in the Himalayan-Tibetan region from teleseismic waveform modeling
Ling Bai1, 2, Jeroen Ritsema2, Junmeng Zhao1
1 Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China 2 Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor MI 48109, USA
摘要We estimate the focal depths and fault plane solutions of 46 moderate earthquakes in the Himalayan- Tibetan region by modeling the broadband waveforms of teleseismic P waves. The depths of 38 of these earthquakes range between 0–40 km, with a peak at ~5 km. One earthquake is located within the lower crust of the Indian shield. The remaining eight earthquakes occurred between depths of 80–120 km and are all located in the Pamir-Hindu Kush and the Indo-Myanmar deep seismic zones. None of the earthquakes outside these deep seismic zones are located in the mantle. Global centroid moment tensor (CMT) solutions indicate that most earthquakes in northern Tibet and northern India had thrust-faulting mechanisms and that normal and strike-slip faulting earthquakes occurred primarily in central Tibet. These mechanisms are consistent with the predominantly NNW-SSE compression in the direction of current Himalayan-Tibetan continental collision.
Abstract:We estimate the focal depths and fault plane solutions of 46 moderate earthquakes in the Himalayan- Tibetan region by modeling the broadband waveforms of teleseismic P waves. The depths of 38 of these earthquakes range between 0–40 km, with a peak at ~5 km. One earthquake is located within the lower crust of the Indian shield. The remaining eight earthquakes occurred between depths of 80–120 km and are all located in the Pamir-Hindu Kush and the Indo-Myanmar deep seismic zones. None of the earthquakes outside these deep seismic zones are located in the mantle. Global centroid moment tensor (CMT) solutions indicate that most earthquakes in northern Tibet and northern India had thrust-faulting mechanisms and that normal and strike-slip faulting earthquakes occurred primarily in central Tibet. These mechanisms are consistent with the predominantly NNW-SSE compression in the direction of current Himalayan-Tibetan continental collision.
基金资助:the grants of 100-talent program of Chinese Academy of Sciences to L. Bai, the US National Science Foundation (EAR-0944167) to J. Ritsema, and the National Natural Science Foundation of China (40930317) to J. Zhao
通讯作者:
Ling Bai
E-mail: bailing@itpcas.ac.cn
引用本文:
Ling Bai, Jeroen Ritsema, Junmeng Zhao. Focal depth estimates of earthquakes in the Himalayan-Tibetan region from teleseismic waveform modeling[J]. 《地震学报》英文版, 2012, 25(5-6): 459-468.
Ling Bai, Jeroen Ritsema, Junmeng Zhao. Focal depth estimates of earthquakes in the Himalayan-Tibetan region from teleseismic waveform modeling. Earthquake Science, 2012, 25(5-6): 459-468.