DOI: 10.1016/j.tecto.2021.229013
论文题名: The 2019 September 24, Mw = 6, Mirpur earthquake, NW Himalaya: Geodetic evidence for shallow, near-horizontal décollement rupture of the Main Himalayan Thrust
作者: Sreejith K.M. ; Jasir M.C.M. ; Agrawal R. ; Rajawat A.S.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 816 语种: 英语
中文关键词: 2019 Mw = 6 Mirpur earthquake
; InSAR
; Low fault friction
; NW Himalaya
; Seismic Hazard
; Slip model
英文关键词: Capillary flow
; Friction
; Indium compounds
; Strain energy
; Synthetic aperture radar
; Accumulated strain
; Bayesian inversion
; Coefficient of frictions
; Coulomb stress changes
; Interferometric synthetic aperture radars
; Main himalayan thrusts
; Pore fluid pressure
; Seismic hazard assessment
; Earthquakes
英文摘要: We present a source model for the 2019 Mw = 6 Mirpur earthquake, NW Himalaya using Interferometric Synthetic Aperture Radar (InSAR) measurements. Bayesian inversion of InSAR data from both ascending and descending orbits suggests that the earthquake ruptured a shallow (Depth ~ 5 km), near-horizontal (Dip ~2.5°) up-dip portion of the décollement of the Main Himalayan Thrust (MHT). The distributed slip model suggests a compact rupture terminating the up-dip end at the base of the Main Frontal Thrust (MFT) with higher slip (> 0.4 m) around the hypocentre, equivalent to a moment magnitude of Mw = 6. A shallow up-dip rupture of the MHT through a moderate magnitude earthquake is atypical as Himalayan earthquakes generally originate at the down-dip portion of the MHT and propagate towards south. We estimate a low effective coefficient of friction of 0.06 ± 0.02 from the slip model and suggest that high pore fluid pressures and/or a weak, lubricated portion of décollement could have caused a local, near-horizontal rupture at the base of the MFT. The 2019 Mirpur earthquake released a small fraction of the accumulated strain energy since the 1555 Kashmir earthquake. Coseismic Coulomb stress change analysis suggests a significant increase in stress on the locked, up-dip portion of the MHT and the frontal fold-thrust system. These findings compel a revisit of the seismic hazard assessment of the northwestern Himalaya. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170906
Appears in Collections: 气候变化与战略
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作者单位: Geosciences Division, Space Applications Centre, Ahmedabad, 380015, India
Recommended Citation:
Sreejith K.M.,Jasir M.C.M.,Agrawal R.,et al. The 2019 September 24, Mw = 6, Mirpur earthquake, NW Himalaya: Geodetic evidence for shallow, near-horizontal décollement rupture of the Main Himalayan Thrust[J]. Tectonophysics,2021-01-01,816