DOI: 10.1016/j.epsl.2020.116413
论文题名: Rupture to the trench? Frictional properties and fracture energy of incoming sediments at the Cascadia subduction zone
作者: Seyler C.E. ; Kirkpatrick J.D. ; Savage H.M. ; Hirose T. ; Faulkner D.R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 546 语种: 英语
中文关键词: Cascadia subduction zone
; earthquake energy budget
; earthquakes
; fault gouge
; fracture energy
; high velocity friction experiments
英文关键词: Earthquakes
; Fracture
; Fracture energy
; Friction
; Sediments
; Shear flow
; Stratigraphy
; Structural geology
; Cascadia subduction zone
; Frictional behavior
; Frictional properties
; In-coming sediments
; Megathrust earthquakes
; Power-law functions
; Rupture propagation
; Shallow earthquakes
; Clay minerals
; accretionary prism
; clay mineral
; earthquake magnitude
; earthquake rupture
; fault gouge
; friction
; lithology
; mechanical property
; sediment
; slip rate
; subduction zone
; trench
; Cascadia Subduction Zone
; Pacific Ocean
英文摘要: The mechanical properties of sediment inputs to subduction zones are important for understanding rupture propagation through the accretionary prism during megathrust earthquakes. Clay minerals strongly influence the frictional behavior of fault gouges, and the clay content of subduction input materials varies through a stratigraphic section as well as for subduction margins globally. To establish the frictional properties of the shallow Cascadia subduction zone and place the results in a global context, we conducted high velocity rotary shear experiments on ODP core samples retrieved from Cascadia input sediments (35-45% clay) and a suite of individual clay species. We compared our results to a compilation of published high velocity experiments conducted on samples of wet gouge, dry gouge, and intact rock. For each sample type, three trends were identified with increasing normal stress: 1) the stress drop (τp−τss) increases linearly, 2) the characteristic thermal weakening distance (Dth) decreases as a power law function except for wet clay-rich gouges, and 3) the fracture energy (Wb) shows no dependence. However, fracture energy does vary with sample type. Clay-rich gouges under wet conditions have the lowest fracture energy, and fracture energy for both dry and wet gouges is at least an order of magnitude lower than estimates from intact rocks. Therefore when clay-rich lithologies are present, they may minimize spatial variations in frictional behavior, allowing earthquakes to propagate to the trench. For Cascadia input sediments, there is little variation in the fracture energy between lithologies, but the fracture energy of Cascadia sediments is around an order of magnitude higher than input sediments from other subduction margins. The high fracture energy of Cascadia sediments relative to other subduction margins may inhibit large amounts of shallow earthquake slip and dynamic overshoot. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165261
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth and Planetary Sciences, McGill University, Montréal, QC, Canada; Department of Earth and Planetary Sciences, University of California, Santa Cruz, CA, United States; Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, Nankoku, Kochi, Japan; School of Environmental Sciences, University of Liverpool, Liverpool, United Kingdom
Recommended Citation:
Seyler C.E.,Kirkpatrick J.D.,Savage H.M.,et al. Rupture to the trench? Frictional properties and fracture energy of incoming sediments at the Cascadia subduction zone[J]. Earth and Planetary Science Letters,2020-01-01,546