DOI: 10.1038/s41561-017-0007-2
论文题名: Links between sediment consolidation and Cascadia megathrust slip behaviour
作者: Han S. ; Bangs N.L. ; Carbotte S.M. ; Saffer D.M. ; Gibson J.C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2017
卷: 10, 期: 12 起始页码: 954
结束页码: 959
语种: 英语
Scopus关键词: accretionary prism
; consolidation
; deformation
; earthquake rupture
; forearc basin
; in situ stress
; physical property
; sediment analysis
; seismic data
; seismic source
; subduction zone
; tectonic wedge
; trench
; Cascadia Subduction Zone
; Oregon
; Pacific Ocean
; United States
; Washington [United States]
英文摘要: At sediment-rich subduction zones, megathrust slip behaviour and forearc deformation are tightly linked to the physical properties and in situ stresses within underthrust and accreted sediments. Yet the role of sediment consolidation at the onset of subduction in controlling the downdip evolution and along-strike variation in megathrust fault properties and accretionary wedge structure is poorly known. Here we use controlled-source seismic data combined with ocean drilling data to constrain the sediment consolidation and in situ stress state near the deformation front of the Cascadia subduction zone. Offshore Washington where the megathrust is inferred to be strongly locked, we find over-consolidated sediments near the deformation front that are incorporated into a strong outer wedge, with little sediment subducted. These conditions are favourable for strain accumulation on the megathrust and potential earthquake rupture close to the trench. In contrast, offshore Central Oregon, a thick under-consolidated sediment sequence is subducting, and is probably associated with elevated pore fluid pressures on the megathrust in a region where reduced locking is inferred. Our results suggest that the consolidation state of the sediments near the deformation front is a key factor contributing to megathrust slip behaviour and its along-strike variation, and it may also have a significant role in the deformation style of the accretionary wedge. © 2017 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105660
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, TX, United States; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Geosciences and Center for Geomechanics, Geofluids, and Geohazards, Pennsylvania State University, University Park, PA, United States
Recommended Citation:
Han S.,Bangs N.L.,Carbotte S.M.,et al. Links between sediment consolidation and Cascadia megathrust slip behaviour[J]. Nature Geoscience,2017-01-01,10(12)