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Slow postseismic recovery of geoid depression formed by the 2004 Sumatra-Andaman Earthquake by mantle water diffusion
| Title: | Slow postseismic recovery of geoid depression formed by the 2004 Sumatra-Andaman Earthquake by mantle water diffusion |
| Authors: | Ogawa, Ryoko Browse this author | | Heki, Kosuke Browse this author →KAKEN DB |
| Keywords: | GRACE | | postseismic change | | Sumatra earthquake |
| Issue Date: | 31-Mar-2007 |
| Publisher: | American Geophysical Union |
| Journal Title: | Geophysical Research Letters |
| Volume: | 34 |
| Issue: | 6 |
| Start Page: | L06313 |
| Publisher DOI: | 10.1029/2007GL029340 |
| Abstract: | Earthquakes are accompanied with mass redistributions and cause changes in gravity field and shape of geoid, an equipotential surface coincident with the mean sea surface. Such coseismic changes were detected by satellite gravimetry after the 2004 Sumatra-Andaman Earthquake [Han et al., 2006], but little has been known on what happens on geoid after the earthquake. Here we report slow postseismic recovery of coseismic geoid depression from satellite measurements. This cannot be explained with simple afterslip or viscous relaxation of Maxwellian upper mantle. It suggests the relaxation of coseismic dilatation and compression by the diffusion of supercritical H2O abundant in the upper mantle. Such a self-healing system of coseismic geoid undulations, a brand-new role of water in mantle, would significantly reduce the amount of permanent shifts of the Earth’s rotation axis by earthquakes. |
| Rights: | An edited version of this paper was published by AGU. Copyright 2007 American Geophysical Union. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/20437 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 日置 幸介
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