DOI: 10.1038/ngeo1927
论文题名: Hydrologic control of forearc strength and seismicity in the Costa Rican subduction zone
作者: Audet P. ; Schwartz S.Y.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2013
卷: 6, 期: 10 起始页码: 852
结束页码: 855
语种: 英语
Scopus关键词: continental crust
; forearc basin
; hydrological regime
; oceanic crust
; permeability
; pore pressure
; rheology
; seismic data
; seismicity
; slip
; spreading center
; subduction zone
; Costa Rica
; Nicoya Peninsula
英文摘要: Subduction zones can exhibit variable seismic behaviour, ranging from great earthquakes to slow slip. This variability may be linked to fault frictional properties, and the rheology and structure of the upper plate. The subduction zone beneath the Nicoya Peninsula, Costa Rica, is characterized by strong variations in fault-slip behaviour and a lateral change in the origin of the subducting plate. In the northwest, the plate interface is locked, and experiences large, infrequent earthquakes, and the subducting plate is formed at the East Pacific Rise. In contrast, in the southeast, slow-slip events occur frequently and the subducting plate is formed at the Cocos-Nazca spreading centre. Here we use seismic receiver-function data to analyse the structure of the subduction zone beneath the Nicoya Peninsula. We find extremely high P-S seismic-velocity ratios within the entire subducting oceanic crust that we interpret as high pore-fluid pressure. Velocity ratios in the overriding continental crust, however, change from lower values in the northwest to higher ones in the southeast, indicating a disparity in fluid accumulation. We infer that this disparity is caused by a higher supply of fluid from the subducting slab in the southeast, owing to the permeability structure of oceanic crust formed at the Cocos-Nazca spreading centre. We suggest that the spatial gradient in fluid content influences upper-plate strength and controls the segmentation of seismogenic behaviour in this subduction zone. © 2013 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106679
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: Department of Earth Sciences, University of Ottawa, ON K1N 6N5, Canada; Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA 95064, United States
Recommended Citation:
Audet P.,Schwartz S.Y.. Hydrologic control of forearc strength and seismicity in the Costa Rican subduction zone[J]. Nature Geoscience,2013-01-01,6(10)