DOI: 10.1038/ngeo2774
论文题名: Earthquake nucleation in weak subducted carbonates
作者: Kurzawski R.M. ; Stipp M. ; Niemeijer A.R. ; Spiers C.J. ; Behrmann J.H.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 9 起始页码: 717
结束页码: 722
语种: 英语
Scopus关键词: carbonate
; convergent margin
; earthquake event
; earthquake rupture
; fault gouge
; nucleation
; plate boundary
; pore pressure
; shear stress
; subduction
英文摘要: Ocean-floor carbonate-and clay-rich sediments form major inputs to subduction zones, especially at low-latitude convergent plate margins. Therefore, knowledge of their frictional behaviour is fundamental for understanding plate-boundary earthquakes. Here we report results of mechanical tests performed on simulated fault gouges prepared from ocean-floor carbonates and clays, cored during IODP drilling offshore Costa Rica. Clay-rich gouges show internal friction coefficients (that is, the slope of linearized shear stress versus normal stress data) of μ int = 0.44 â ' 0.56, irrespective of temperature and pore-fluid pressure (P f). By contrast, μ int for the carbonate gouge strongly depends on temperature and pore-fluid pressure, with μ int decreasing dramatically from 0.84 at room temperature and P f = 20 MPa to 0.27 at T = 140 °C and P f = 120 MPa. This effect provides a fundamental mechanism of shear localization and earthquake generation in subduction zones, and makes carbonates likely nucleation sites for plate-boundary earthquakes. Our results imply that rupture nucleation is prompted by a combination of temperature-controlled frictional instability and temperature-and pore-pressure-dependent weakening of calcareous fault gouges. © 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105926
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 Marine Geodynamics, GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, Kiel, Germany; Institute of Geosciences, University of Kiel, Ludewig-Meyn-Str. 10, Kiel, Germany; HPT Laboratory, Department of Earth Sciences, Utrecht University, Budapestlaan 4, Utrecht, Netherlands
Recommended Citation:
Kurzawski R.M.,Stipp M.,Niemeijer A.R.,et al. Earthquake nucleation in weak subducted carbonates[J]. Nature Geoscience,2016-01-01,9(9)