DOI: 10.1038/NGEO3011
论文题名: Intermediate-depth earthquakes linked to localized heating in dunite and harzburgite
作者: Ohuchi T. ; Lei X. ; Ohfuji H. ; Higo Y. ; Tange Y. ; Sakai T. ; Fujino K. ; Irifune T.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2017
卷: 10, 期: 10 起始页码: 771
结束页码: 775
语种: 英语
Scopus关键词: antigorite
; dunite
; earthquake
; fault plane
; harzburgite
; heating
; slab
; strain rate
; subduction
英文摘要: The occurrence of intermediate-depth and deep earthquakes at depths greater than 60 km in subducting slabs has long puzzled geoscientists. These earthquakes require some mechanism to accelerate the fault movement at high pressures above 1.8 GPa. Localized heating would contribute to faulting, but experimental evidence for this mechanism has been limited to pressures of up to 0.5 GPa. Here we conduct deformation experiments on dry dunite samples at pressures of 1.0 to 2.6 GPa and temperatures of 860 to 1,350 K - conditions close to those for relatively shallow intermediate-depth earthquakes. We observe plastic deformation of the dunite, followed by faulting and acoustic emissions at an accelerated strain rate of about 5 × 10(-5) s(-1) or higher. We find that ultrafine-grained gouge layers containing iron-rich melt films, which is indicative of a very high peak temperature of about 2,110 K along the fault planes. We also observe faulting in wet harzburgite - a dehydration product of antigorite - at natural stress levels of 0.3 to 0.4 gigapascals. We therefore suggest that intermediate-depth earthquakes can be induced by localized heating both in dry and wet subducting slabs, if the background strain rate exceeds a threshold value in the range from 10(-16) to 10(-13) s(-1). © 2017 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/105691
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: Geodynamics Research Center, Ehime University, Matsuyama, Japan; Geological Survey of Japan, National Institute for Advanced Industrial Science and Technology, Tsukuba, Japan; Japan Synchrotron Radiation Research Institute, Sayo, Hyogo, Japan; Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
Recommended Citation:
Ohuchi T.,Lei X.,Ohfuji H.,et al. Intermediate-depth earthquakes linked to localized heating in dunite and harzburgite[J]. Nature Geoscience,2017-01-01,10(10)