DOI: 10.1002/grl.50468
论文题名: Seismic evidence for high pore pressures in the oceanic crust: Implications for fluid-related embrittlement
作者: Shiina T. ; Nakajima J. ; Matsuzawa T.
刊名: Geophysical Research Letters
ISSN: 0094-9004
EISSN: 1944-8735
出版年: 2013
卷: 40, 期: 10 起始页码: 2006
结束页码: 2010
语种: 英语
英文关键词: dehydration
; oceanic crust
; Pacific plate
; PS-converted wave
; seismicity
; tomography
Scopus关键词: Arrival-time data
; Effective normal stress
; Mid-ocean ridge basalt
; Oceanic crust
; P-wave velocity structure
; Pacific plates
; Pore fluid pressure
; seismicity
; Acoustic wave velocity
; Dehydration
; Embrittlement
; Plates (structural components)
; Seismic waves
; Tomography
; Wave propagation
; Earthquakes
; dehydration
; earthquake event
; metamorphosis
; oceanic crust
; P-wave
; pore pressure
; S-wave
; seismic anisotropy
; seismicity
; tomography
; wave velocity
; Japan
; Pacific Ocean
英文摘要: We estimated the P wave velocity structure of the crust of the subducting Pacific plate beneath northeast Japan using arrival time data of P-to-S-converted waves. The results show that the P wave velocity of the subducting crust varies along the arc and increases abruptly at a depth of ∼100 km, from 6.5-7.0 km/s in the fore arc to 7.5-8.5 km/s in the back arc. The P wave velocity in the fore arc is ∼10% lower than theoretically expected values for the metamorphosed mid-ocean ridge basalt material. Seismicity in the subducting crust is most active at depths of 70-80 km where P wave velocities are lowest. The marked reduction of P wave velocity suggests the coexistence of aqueous fluids with hydrous minerals. Abundant fluids elevate pore fluid pressures and reduce effective normal stress, promoting intensive seismic activity in the low-velocity crust. Our observations provide seismic evidence that earthquakes in the subducting crust are facilitated by fluid-related embrittlement. © 2013 American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879962090&doi=10.1002%2fgrl.50468&partnerID=40&md5=9fb67ac2de9b49bb707155bdfda491b2
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6268
Appears in Collections: 气候减缓与适应
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作者单位: Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
Recommended Citation:
Shiina T.,Nakajima J.,Matsuzawa T.. Seismic evidence for high pore pressures in the oceanic crust: Implications for fluid-related embrittlement[J]. Geophysical Research Letters,2013-01-01,40(10).