DOI: 10.1038/ngeo2343
论文题名: Randomness of megathrust earthquakes implied by rapid stress recovery after the Japan earthquake
作者: Tormann T. ; Enescu B. ; Woessner J. ; Wiemer S.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2015
卷: 8, 期: 2 起始页码: 152
结束页码: 158
语种: 英语
Scopus关键词: earthquake event
; plate tectonics
; rupture
; seismic hazard
; stress analysis
; subduction zone
; Japan
; Pacific Ocean
英文摘要: Constraints on the recurrence times of subduction zone earthquakes are important for seismic hazard assessment and mitigation. Models of such megathrust earthquakes often assume that subduction zones are segmented and earthquakes occur quasi-periodically owing to constant tectonic loading. Here we analyse the occurrence of small earthquakes compared to larger ones - the b-values - on a 1,000-km-long section of the subducting Pacific Plate beneath central and northern Japan since 1998. We find that the b-values vary spatially and mirror the tectonic regime. For example, high b-values, indicative of low stress, occur in locations characterized by deep magma chambers and low b-values, or high stress, occur where the subducting and overriding plates are strongly coupled. There is no significant variation in the low b-values to suggest the plate interface is segmented in a way that might limit potential ruptures. Parts of the plate interface that ruptured during the 2011 Tohoku-oki earthquake were highly stressed in the years leading up to the earthquake. Although the stress was largely released during the 2011 rupture, we find that the stress levels quickly recovered to pre-quake levels within just a few years. We conclude that large earthquakes may not have a characteristic location, size or recurrence interval, and might therefore occur more randomly distributed in time. © 2015 Macmillan Publishers Limited. All rights reserved Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106294
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: ETH Zurich, Swiss Seismological Service, Sonneggstrasse 5, Zürich, Switzerland; University of Tsukuba, Faculty of Life and Environmental Sciences, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan; Risk Management Solutions Inc., Stampfenbachstrasse 85, Zürich, Switzerland
Recommended Citation:
Tormann T.,Enescu B.,Woessner J.,et al. Randomness of megathrust earthquakes implied by rapid stress recovery after the Japan earthquake[J]. Nature Geoscience,2015-01-01,8(2)