Down-dip variations in a subducting low-velocity zone linked to episodic tremor and slip: a new constraint from ScSp waves
書誌事項
- 公開日
- 2017-06-06
- 資源種別
- journal article
- 権利情報
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- https://creativecommons.org/licenses/by/4.0
- https://creativecommons.org/licenses/by/4.0
- DOI
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- 10.1038/s41598-017-03048-6
- 公開者
- Springer Science and Business Media LLC
説明
<jats:title>Abstract</jats:title><jats:p>Fluids are thought to play an important role in controlling episodic tremor and slow slip (ETS) in subduction zones. Therefore, constraining the along-dip distribution of fluids is necessary to better understand source mechanism of ETS, and particularly the role played by fluids in ETS generation. Here, we report clear observations of coherent <jats:italic>ScSp</jats:italic> phases with a dense seismic array in western Shikoku, Japan, where ETS has been most active over the past decade. Using numerical simulations of elastic-wave propagation to reproduce the observed <jats:italic>ScSp</jats:italic> phases, we demonstrate that, relative to shallower depths, either the V<jats:sub>p</jats:sub>/V<jats:sub>s</jats:sub> ratio or the thickness of a low-velocity zone (LVZ) within the subducting oceanic crust increases with depth beneath the mantle wedge corner where ETS has been observed. Based on these depth dependences of the structural elements, a wide semi-ductile shear zone appears to be lubricated by high-pressurized fluid in the subducting oceanic crust at ETS source depths, and to be a key factor regulating ETS activity.</jats:p>
収録刊行物
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- Scientific Reports
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Scientific Reports 7 (1), 2868-, 2017-06-06
Springer Science and Business Media LLC
