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Opal-CT in chert beneath the toe of the Tohoku margin and its influence on the seismic aseismic transition in subduction zones
| Title: | Opal-CT in chert beneath the toe of the Tohoku margin and its influence on the seismic aseismic transition in subduction zones |
| Authors: | Kameda, Jun Browse this author | | Okamoto, Atsushi Browse this author | | Sato, Kiminori Browse this author | | Fujimoto, Koichiro Browse this author | | Yamaguchi, Asuka Browse this author | | Kimura, Gaku Browse this author |
| Keywords: | chert | | pressure solution creep | | asperity |
| Issue Date: | 28-Jan-2017 |
| Publisher: | American Geophysical Union |
| Journal Title: | Geophysical research letters |
| Volume: | 44 |
| Issue: | 2 |
| Start Page: | 687 |
| End Page: | 693 |
| Publisher DOI: | 10.1002/2016GL071784 |
| Abstract: | Thick accumulation of chert is a ubiquitous feature of old oceanic plates at convergent margins. In this study, we investigate chert fragments recovered by the Integrated Ocean Drilling Program expedition 343 at the Japan Trench where the 2011 Tohoku-Oki earthquake (M-w 9.0) occurred. This sample provides a unique opportunity to investigate in situ chert diagenesis at an active subduction margin and its influence on the kinematics of megathrust faulting. Our mineralogical analyses revealed that the chert is characterized by hydrous opal-CT and may therefore be highly deformable via pressure solution creep and readily accommodate shear strain between the converging plates at driving stresses of kilopascal order. As chert diagenesis advances, any further deformation requires stresses of >100MPa, given the increasing transport distances for solutes as represented in cherts on land. The chert diagenesis is thus related to the mechanical transition from a weakly to strongly coupled plate interface at this margin. |
| Rights: | An edited version of this paper was published by AGU. Copyright 2017 American Geophysical Union. Kameda, J., A. Okamoto, K. Sato, K. Fujimoto, A. Yamaguchi, and G. Kimura
(2017), Opal-CT in chert beneath the toe
of the Tohoku margin and its influence
on the seismic aseismic transition in
subduction zones, Geophys. Res. Lett., 44,
687–693, doi:10.1002/2016GL071784. To view the published open abstract, go to http://dx.doi.org and enter the DOI. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/66866 |
| 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: 亀田 純
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