气候变化领域集成服务门户(CCPortal): Seismogenic thickness of California: Implications for thermal structure and seismic hazard

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DOI	10.1016/j.tecto.2020.228426
	Seismogenic thickness of California: Implications for thermal structure and seismic hazard
	Zuza A.V.; Cao W.
发表日期	2020
ISSN	00401951
卷号	782-783
英文摘要	The seismogenic thickness of the crust, a proxy for brittle-crust thickness, is a geometric parameter related to crustal strength, seismic hazard, and the crust's thermo-mechanical nature. We use high-resolution earthquake-location data from California to construct a topographic map of the base of the seismogenic crust by calculating the depth above which 95% of seismicity (D95) is located for fixed width bins. Seismogenic thickness is highly variable, ranging from ~5 km to >30 km, with thicker D95 values in the Great Valley-Sierra Nevada and thinner values in the Walker Lane and northern coastal California. Seismogenic thickness is inversely correlated with surface heat flow in most locations, consistent with a steady-state conductive crust, and local deviations probably reflect non-steady-state conditions related to magmatism and/or hydrothermal circulation. Such correlation suggests that, at regional scale, brittle-ductile transition (BDT) depth is mostly controlled by geothermal gradients, and the base of the seismogenic crust essentially represents a BDT isotherm (~300–350 °C for quartz-dominated lithologies). Spatial variations of D95 depths across California can be used to evaluate or constrain the locations of future seismicity, propagation direction of earthquake ruptures, and maximum depth, rupture area, and magnitude of future strike-slip earthquake events. Thicker seismogenic crust has a greater integrated strength. Seismogenic depth asperities, which represent mechanically stronger crustal patches, may focus and nucleate future earthquake events and/or impede rupture propagation. © 2020 Elsevier B.V.
关键词	Brittle-ductile transition Crustal strength D95 Heat flow Seismic hazard Seismogenic thickness
英文关键词	Hazards; Location; Maps; Seismic response; Brittle ductile transitions; Geothermal gradients; Hydrothermal circulation; Non-steady-state conditions; Propagation direction; Rupture propagation; Strike-slip earthquakes; Thermo-mechanical nature; Earthquakes; crustal thickness; earthquake hypocenter; earthquake rupture; geometry; seismic hazard; seismicity; spatial variation; thermal structure; topographic mapping; California; Central Valley [California]; Sierra Nevada [California]; United States; Walker Lane; Calluna vulgaris
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/207923
作者单位	Nevada Bureau of Mines and Geology, University of Nevada, Reno, NV 89557, United States; Department of Geological Sciences and Engineering, University of Nevada, Reno, NV 89557, United States
推荐引用方式 GB/T 7714	Zuza A.V.,Cao W.. Seismogenic thickness of California: Implications for thermal structure and seismic hazard[J],2020,782-783.
APA	Zuza A.V.,&Cao W..(2020).Seismogenic thickness of California: Implications for thermal structure and seismic hazard.Tectonophysics,782-783.
MLA	Zuza A.V.,et al."Seismogenic thickness of California: Implications for thermal structure and seismic hazard".Tectonophysics 782-783(2020).