Item type |
デフォルトアイテムタイプ(フル)(1) |
公開日 |
2020-06-24 |
タイトル |
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タイトル |
Tectonics and mechanism of a spreading ridge subduction at the Chile Triple Junction based on new marine geophysical data |
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言語 |
en |
作成者 |
Matsumoto, Takeshi
Mori, Asuka
Kise, Shinichiro
Abe, Natsue
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アクセス権 |
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アクセス権 |
open access |
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アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
主題 |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
Chile Ridge |
主題 |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
Chile Triple Junction |
主題 |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
Chile Trench |
主題 |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
Outer Gravity High |
主題 |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
slab-pull |
内容記述 |
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内容記述タイプ |
Other |
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内容記述 |
The Chile Triple Junction (CTJ), an RTT-type triple junction located at 46°13′ S, 75°48′ W off the western coast of Chile, is characterized by the subducting Chile Ridge, which is the constructive plate boundary that generates both the Nazca Plate and the Antarctic Plate. The ridge subduction mechanism and the regional tectonics around the CTJ were investigated primarily using marine geophysical data (topography, gravity, geomagnetic field and single-channel seismics) collected during the SORA2009 cruise (Cruise ID = MR08-06) by R/V MIRAI together with other cruise data from the National Geophysical Data Center. The segment of the ridge axis just before the subduction around the CTJ is associated with an axial deep covered with thick sediment unlike that seen in typical ridge crests. The profiles of both topography and the free air anomaly around the CTJ show quite different patterns from those of ordinary subduction zones. However, topographic features typical of a slow-spreading type ridge, including a median valley and both flanks, remain in the seaward side of the trench. Even after the subduction of the eastern flank, the topographic features of the western flank remain. A slight Outer Rise and an Outer Gravity High, which are common in the western Pacific area, were observed in an area far away from the CTJ on both Nazca and Antarctic plate sides. The geomagnetic anomaly pattern around the Chile Ridge near the CTJ shows that the estimated spreading rate decreases gradually towards the ridge crest. This suggests that volcanic activity diminishes gradually towards the subducting ridge axis. The lithosphere under the Chile Ridge might have amalgamated with the surrounding oceanic lithosphere due to heat loss after the cessation of volcanic activity. The oceanic lithosphere towards the trench also thickens rapidly due to heat loss. Consequently, shallow-angle subduction of the youngest and most immature oceanic plate occurs smoothly via slab-pull force without any resistance along the interface between the South American continental plates. |
内容記述 |
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内容記述タイプ |
Other |
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内容記述 |
論文 |
出版者 |
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言語 |
en |
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出版者 |
The Geochemical Society of Japan |
出版者 |
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言語 |
ja |
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出版者 |
日本地球化学会 |
言語 |
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言語 |
eng |
資源タイプ |
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資源タイプ |
journal article |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
出版タイプ |
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出版タイプ |
VoR |
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出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
識別子 |
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識別子 |
http://hdl.handle.net/20.500.12000/46278 |
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識別子タイプ |
HDL |
関連情報 |
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識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.2343/geochemj.2.0257 |
関連情報 |
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識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.2343/geochemj.2.0257 |
収録物識別子 |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
1880-5973 |
収録物識別子 |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
0016-7002 |
収録物名 |
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言語 |
en |
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収録物名 |
GEOCHEMICAL JOURNAL |
書誌情報 |
巻 47,
号 2,
p. 137-147,
発行日 2013-04-20
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