DOI: 10.1038/ngeo2547
论文题名: Spectrum of slip behaviour in Tohoku fault zone samples at plate tectonic slip rates
作者: Ikari M.J. ; Ito Y. ; Ujiie K. ; Kopf A.J.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 11 起始页码: 870
结束页码: 874
语种: 英语
Scopus关键词: fault zone
; laboratory method
; long-term change
; plate convergence
; plate tectonics
; rock property
; seafloor
; shear strength
; slope dynamics
; spectrum
; subduction zone
; Tohoku earthquake 2011
; Honshu
; Japan
; Tohoku
英文摘要: During the 2011 Tohoku-oki earthquake, extremely extensive coseismic slip ruptured shallow parts of the Japan Trench subduction zone and breached the sea floor. This part of the subduction zone also hosts slow slip events (SSE). The fault thus seems to have a propensity for slip instability or quasi-instability that is unexpected on the shallow portions of important fault zones. Here we use laboratory experiments to slowly shear samples of rock recovered from the Tohoku-oki earthquake fault zone as part of the Japan Trench Fast Drilling Project. We find that infrequent perturbations in rock strength appear spontaneously as long-term SSE when the samples are sheared at a constant rate of about 8.5cmyr -1, equivalent to the plate-convergence rate. The shear strength of the rock drops by 3 to 6%, or 50kPa to 120kPa, over about 2 to 4h. Slip during these events reaches peak velocities of up to 25cmyr -1, similar to SSE observed in several circum-Pacific subduction zones. Furthermore, the sheared samples exhibit the full spectrum of fault-slip behaviours, from fast unstable slip to slow steady creep, which can explain the wide range of slip styles observed in the Japan Trench. We suggest that the occurrence of SSE at shallow depths may help identify fault segments that are frictionally unstable and susceptible to large coseismic slip propagation. © 2015 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106143
Appears in Collections: 气候减缓与适应 科学计划与规划
There are no files associated with this item.
作者单位: MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Disaster Prevention Research Institute, Kyoto University, Gokasyo, Uji, Japan; Research and Development Center for Ocean Drilling Science, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
Recommended Citation:
Ikari M.J.,Ito Y.,Ujiie K.,et al. Spectrum of slip behaviour in Tohoku fault zone samples at plate tectonic slip rates[J]. Nature Geoscience,2015-01-01,8(11)