Los Alamos National Laboratory
Massachusetts Institute of Technology
Earthquake Research Institute, University of Tokyo
抄録
Since the discovery of extensive earthquake triggering occurring in response to the 1992 Mw (moment magnitude) 7.3 Landers earthquake, it is now well established that seismic waves from earthquakes can trigger other earthquakes, tremor, slow slip, and pore pressure changes. Our contention is that earthquake triggering is one manifestation of a more widespread elastic disturbance that reveals information about Earth’s stress state. Earth’s stress state is central to our understanding of both natural and anthropogenic-induced crustal processes. We show that seismic waves from distant earthquakes may perturb stresses and frictional properties on faults and elastic moduli of the crust in cascading fashion. Transient dynamic stresses place crustal material into a metastable state during which the material recovers through a process termed slow dynamics. This observation of widespread, dynamically induced elastic perturbation, including systematic migration of offshore seismicity, strain transients, and velocity transients, presents a new characterization of Earth’s elastic system that will advance our understanding of plate tectonics, seismicity, and seismic hazards.
内容記述
UTokyo Research掲載「スマトラ地震により東北日本の地殻の状態が次々と変化」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/sumatra-earthquake-caused-changes-in-Earths-crust-in-japan.html
UTokyo Research "Sumatra earthquake caused changes in Earth’s crust in Japan" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/sumatra-earthquake-caused-changes-in-Earths-crust-in-japan.html
Cascading elastic perturbation in Japan due to the 2012 Mw 8.6 Indian Ocean earthquake
e1500468.full.pdf
(1.58MB)
