玄武岩質火山成長に伴うカルデラ形成 重力崩壊モデル
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- 高田 亮
- 産業技術総合研究所地球科学情報研究部門
書誌事項
- タイトル別名
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- Caldera Formation Associated with the Growth of a Basaltic Volcano: A Model for Gravitational Collapse.
- ゲンブガンシツ カザン セイチョウ ニ トモナウ カルデラ ケイセイ ジュウリョク ホウカイ モデル
- A Model for Gravitational Collapse
- 重力崩壊モデル
- 公開日
- 2001
- DOI
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- 10.5026/jgeography.110.2_245
- 公開者
- 公益社団法人 東京地学協会
この論文をさがす
説明
Basaltic volcanoes above oceanic crust or island-arc crusts develop calderas. Upon the formation of this caldera, the collapsed volume was generally far larger than erupted volume. Caldera width, its depth, and caldera horizontal width (CR) / volcano size (VR) depend on the physical properties of an oceanic crust. The CR/VR ratio decreases away from the ridge. At Fernandina volcano, Galapagos, the elongated caldera of 3.5 km × 2.5 km was formed in 1968 during a phase dominated by circumferential fissure eruptions after a phase dominated by radial fissure eruptions. At Kilauea volcano, Hawaii, during a phase dominated by central eruptions, several drain backs of lava lake ccurred from 1800, and, finally, a caldera of 1 km in diameter collapsed in 1924. Caldera collapse seems to be inevitable because accumulated crystals and solidified magma under a volcano increases gravitational instability. According to the gravitational collapse model proposed in this paper, it is difficult to determine when, how wide, and how deep a caldera collapse will occur. The magma plumbing system expands horizontally and vertically during long-term growth. Caldera collapse should contribute to vertical growth. Horizontal growth and vertical growth are governed by physical properties of the crust beneath the volcano; the former process is dominant in Hawaii, and the latter in Galapagos. In the case of Miyakejima volcano, the caldera collapse may be triggered by dike intrusions into a region with a low probability of intrusions or by an increase in the magma supply beneath the magma chamber. At the Miyakejima eruption in 2000, the caldera of 1.5 km in diameter formed in the shallow crust; ductile mass or dense magma with crystal mush may have moved downward or northwestward in the deep crust.
収録刊行物
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- 地学雑誌
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地学雑誌 110 (2), 245-256, 2001
公益社団法人 東京地学協会
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詳細情報 詳細情報について
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- CRID
- 1390282679206656640
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- NII論文ID
- 110000379926
- 10010519820
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- NII書誌ID
- AN00322536
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- ISSN
- 18840884
- 0022135X
- http://id.crossref.org/issn/0022135X
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- NDL書誌ID
- 5776565
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- 本文言語コード
- ja
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- データソース種別
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- JaLC
- NDLサーチ
- Crossref
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可
