气候变化领域集成服务门户(CCPortal): Relaxation of Tibetan Lower Crust and Afterslip Driven by the 2001 Mw7.8 Kokoxili, China, Earthquake Constrained by a Decade of Geodetic Measurements

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DOI	10.1029/2020JB021314
	Relaxation of Tibetan Lower Crust and Afterslip Driven by the 2001 Mw7.8 Kokoxili, China, Earthquake Constrained by a Decade of Geodetic Measurements
	Zhao D.; Qu C.; Bürgmann R.; Gong W.; Shan X.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	We model the time-dependent postseismic displacements following the 2001 Mw7.8 Kokoxili earthquake, including both GPS (2001–2002 for near-field and 2001–2010 for far-field) and descending-track InSAR line-of-sight time series (2003–2010) to study three postseismic deformation processes. The predicted deformation patterns and magnitude from poroelastic rebound are inconsistent with the geodetic observations. Far-field postseismic deformation (>200 km from rupture) is primarily induced by upper mantle viscoelastic relaxation beneath Tibet and the Qaidam Basin and places a lower bound on transient and steady-state viscosities on the order of 1019–1020 Pas. Shallow stress-driven afterslip (<20 km) on the Kunlun Pass fault localizes deformation in the near-fault area and helps explain the GPS-measured displacement gradient across the fault. Deep stress-driven afterslip in the downdip region of the coseismic rupture (>20 km) has an amplitude of ∼1 m during the first 3 years. Our results indicate that the consideration of deep afterslip increases our estimates of transient viscosity of the lower crust beneath Tibet and the Qaidam basin for this earthquake by as much as a factor of three. Our combined model incorporating viscoelastic relaxation and afterslip suggests that the effective transient and steady-state viscosities in the Tibetan lower crust are 5 × 1018 Pas and 4 × 1019 Pas, respectively (transient viscosity = 2 × 1018 Pas without afterslip considered), while the effective transient and steady-state viscosities below the Qaidam Basin area are 1 × 1019 Pas and 6 × 1019 Pas (transient viscosity = 4 × 1018 Pas without afterslip considered). © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Kokoxili earthquake; Kunlun fault; postseismic deformation processes; stress-driven afterslip; viscoelastic relaxation
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187207
作者单位	State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing, China; Department of Earth and Planetary Science and Berkeley Seismology Lab, University of California, Berkeley, CA, United States
推荐引用方式 GB/T 7714	Zhao D.,Qu C.,Bürgmann R.,et al. Relaxation of Tibetan Lower Crust and Afterslip Driven by the 2001 Mw7.8 Kokoxili, China, Earthquake Constrained by a Decade of Geodetic Measurements[J],2021,126(4).
APA	Zhao D.,Qu C.,Bürgmann R.,Gong W.,&Shan X..(2021).Relaxation of Tibetan Lower Crust and Afterslip Driven by the 2001 Mw7.8 Kokoxili, China, Earthquake Constrained by a Decade of Geodetic Measurements.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Zhao D.,et al."Relaxation of Tibetan Lower Crust and Afterslip Driven by the 2001 Mw7.8 Kokoxili, China, Earthquake Constrained by a Decade of Geodetic Measurements".Journal of Geophysical Research: Solid Earth 126.4(2021).