DOI: 10.1007/s11430-018-9441-6
论文题名: The focal depths of the 2008 Panzhihua earthquake sequence and the stress field in the source region
作者: Luo Y. ; Zhao L. ; Tian J.
刊名: Science China Earth Sciences
ISSN: 16747313
出版年: 2020
卷: 63, 期: 3 语种: 英语
英文关键词: Depth phase
; Focal mechanism solution
; Panzhihua earthquake sequence
; Tectonic stress field
Scopus关键词: Shear waves
; Stresses
; Strike-slip faults
; Velocity
; Centroid moment tensors
; Depth phase
; Earthquake sequences
; Focal mechanism
; Horizontal movements
; Strike slip faulting
; Strike-slip mechanism
; Tectonic stress fields
; Earthquakes
; earthquake event
; earthquake intensity
; earthquake magnitude
; earthquake rupture
; extensional tectonics
; focal mechanism
; P-wave
; S-wave
; seismic velocity
; stress field
; China
; Panzhihua
; Sichuan
英文摘要: Focal depths of the 2008 MS6.1 Panzhihua earthquake sequence and tectonic stress field in the source area are investigated. Source depths of 24 earthquakes in Panzhihua earthquake sequence with a magnitude M≥3.0 were determined using the seismic depth phase sPL; additionally, the focal depths of 232 earthquakes were measured by fitting the three-component waveforms of the P and S waves. The source depth of the main shock is ~12 km. The majority of the aftershocks with magnitude M≥3.0 occurred in the brittle upper crust at the depths range of 12–18 km. Further, the Source mechanisms of the 232 events around the Panzhihua earthquake source area were determined, and the results show that the earthquakes have predominantly strike-slip mechanisms in the Dianzhong Block, but display complexity of the focal mechanisms outside and near the boundary of the Dianzhong block. The 232 earthquake mechanisms from this study are combined with the solutions from the Global Centroid Moment Tensor (GCMT) catalog to derive 2D stress field. The inversion results show that the Dianzhong block is predominantly under a strike slip faulting regime and the direction of the maximum principal compression σ1 is northwest-southeast (NW-SE)-trending. The distribution is coincide with GPS velocity field. However, orientations of principal stress axes as well as the faulting types change outside and near the Dianzhong block. The results show that the tectonic stress field in the study area is predominantly controlled by the southeast (SE)-trending horizontal movement and clockwise rotation of the Dianzhong block as a result of the eastward movement of eastern Tibetan meeting the old and rigid South China block (SCB). The Panzhihua earthquake ruptured at ~12 km depth where the tectonic stress regime is under the SE-direction horizontal compression and the NE-direction horizontal extension. © 2019, Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/159170
Appears in Collections: 气候变化与战略
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作者单位: Key Laboratory of Earthquake Prediction, Institute of Earthquake Forecasting, CEA, Beijing, 100036, China; School of Earth and Space Sciences, Peking University, Beijing, 100871, China
Recommended Citation:
Luo Y.,Zhao L.,Tian J.. The focal depths of the 2008 Panzhihua earthquake sequence and the stress field in the source region[J]. Science China Earth Sciences,2020-01-01,63(3)