气候变化领域集成服务门户(CCPortal): Pore Pressure Regime and Fluid Flow Processes in the Shallow Nankai Trough Subduction Zone Based on Experimental and Modeling Results from IODP Site C0023

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DOI	10.1029/2020JB020248
	Pore Pressure Regime and Fluid Flow Processes in the Shallow Nankai Trough Subduction Zone Based on Experimental and Modeling Results from IODP Site C0023
	Zhang J.; Hüpers A.; Kreiter S.; Kopf A.J.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	Pore fluid pressure is a critical parameter controlling the dynamics of subduction zones and related geological hazards, but quantitative constraints on pore pressure are sparse. Here we provide robust estimates of pore pressure in the shallow Nankai Trough subduction zone based on consolidation experiments and numerical models. Our experimental data reveal excess pore pressures with nearly constant ratios of pore pressure to lithostatic stress for the accreted and underthrust sediments, implying the décollement is not a fluid barrier as previously inferred. Also, our research suggests repeated lithostatic pore pressure transients in the last 3 kyrs, probably associated with the propagation of the frontal thrust. The coupled pore pressure dissipation and chemical transport model results let us conclude the updip migration fluid originates from an overpressured horizon nearby, confirming the view of a heterogeneous plate boundary with overpressured and permeable patches along the fault surface that shift in time and space. The resulting high excess pore pressure leads to the shear strength of Nankai subduction thrust as low as 0.4–0.8 MPa. This provides quantitative constraints on the weakness of subduction thrusts at the toe of accretionary prisms and may explain why seismic slip can propagate all the way to the trench in some earthquakes (e.g., 2011 Tohoku event). © 2021. The Authors.
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/187344
作者单位	MARUM—Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, Germany
推荐引用方式 GB/T 7714	Zhang J.,Hüpers A.,Kreiter S.,et al. Pore Pressure Regime and Fluid Flow Processes in the Shallow Nankai Trough Subduction Zone Based on Experimental and Modeling Results from IODP Site C0023[J],2021,126(2).
APA	Zhang J.,Hüpers A.,Kreiter S.,&Kopf A.J..(2021).Pore Pressure Regime and Fluid Flow Processes in the Shallow Nankai Trough Subduction Zone Based on Experimental and Modeling Results from IODP Site C0023.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Zhang J.,et al."Pore Pressure Regime and Fluid Flow Processes in the Shallow Nankai Trough Subduction Zone Based on Experimental and Modeling Results from IODP Site C0023".Journal of Geophysical Research: Solid Earth 126.2(2021).