气候变化领域集成服务门户(CCPortal): Observation-constrained multicycle dynamic models of the Pingding Shan earthquake gate along the Altyn Tagh Fault

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DOI	10.1016/j.tecto.2021.228948
	Observation-constrained multicycle dynamic models of the Pingding Shan earthquake gate along the Altyn Tagh Fault
	Liu D.; Duan B.; Prush V.B.; Oskin M.E.; Liu-Zeng J.
发表日期	2021
ISSN	00401951
卷号	814
英文摘要	Earthquake gates are fault geometric complexities, common in natural fault systems, that conditionally impede earthquake ruptures. This study centers on modeling of multicycle dynamics of the Pingding Shan earthquake gate along the central Altyn Tagh Fault in northwest China. The earthquake gate includes three geometric complexities: a prominent restraining bend, a 4-km wide stepover to the east, and a releasing bend to the west. We use a 2D finite element method to simulate coseismic spontaneous ruptures with interseismic fault stress evolutions computed by an analytic viscoelastic solution. Paleoseismic records and long-term slip-rates are used to constrain the models. We find that fault-geometry-related heterogenous stresses accumulated over earthquake cycles yield complex rupture patterns and help explain earthquake recurrence intervals revealed by paleoseismic records. The three most important contributions to the heterogeneous stresses come from dynamic ruptures passing fault geometric complexities, fault-strike-dependent tectonic loading and relaxation, and stress history from past earthquakes. In the Pingding Shan earthquake gate, the releasing stepover appears to impede ruptures more effectively than the restraining bend. The combined impact of the restraining bend and the releasing stepover makes the Pingding Shan earthquake gate a very effective barrier to 350-km model-spanning ruptures. The best-fit model yields a low recurrence interval of 4.6 kyrs for 350-km-long ruptures, interspersed with more frequent ruptures limited to individual fault segments. A lower static friction tends to reduce the effectiveness of the earthquake gate to impede ruptures. Local fault geometric complexities together with rapid energy release and restrengthening of friction during dynamic ruptures help explain the 0.66 recurrence interval coefficient of variation (COV) recorded at the Copper Mine paleoseismic trench site on the Xorxoli segment. This study provides a method for applying heterogenous initial stresses for single-event dynamic rupture simulations that consider the effect of past earthquakes and fault geometry. © 2021 Elsevier B.V.
关键词	Altyn Tagh fault Dynamic rupture Earthquake cycle Earthquake gate Fault geometric complexity Stress heterogeneity
英文关键词	Copper mines; Faulting; Geometry; Stiction; 2-D finite element method; Dynamic ruptures; Earthquake cycles; Earthquake recurrence intervals; Earthquake rupture; Geometric complexity; Recurrence intervals; Stress evolution; Earthquakes; earthquake event; earthquake rupture; fault geometry; finite element method; model; recurrence interval; stress field; Altyn Tagh Fault Zone; China
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208014
作者单位	Center for Tectonophysics, Department of Geology & Geophysics, Texas A&M University, College Station, TX 77843-3115, United States; Department of Earth and Planetary Sciences, University of California, Davis, 1 Shields Avenue, Davis, CA 95616, United States; Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
推荐引用方式 GB/T 7714	Liu D.,Duan B.,Prush V.B.,et al. Observation-constrained multicycle dynamic models of the Pingding Shan earthquake gate along the Altyn Tagh Fault[J],2021,814.
APA	Liu D.,Duan B.,Prush V.B.,Oskin M.E.,&Liu-Zeng J..(2021).Observation-constrained multicycle dynamic models of the Pingding Shan earthquake gate along the Altyn Tagh Fault.Tectonophysics,814.
MLA	Liu D.,et al."Observation-constrained multicycle dynamic models of the Pingding Shan earthquake gate along the Altyn Tagh Fault".Tectonophysics 814(2021).