逆転した大陸のモホと,前弓のマントルの蛇形化
M G Bostock1, R D Hyndman, S Rondenay
1Department of Earth and Ocean Sciences, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada. bostock@geop.ubc.ca
Nature
|May 31, 2002
まとめ
潜水板は揮発性物質を放出し,融解と火山活動を引き起こします. カスカディア・サブドクション・ゾーンでは,地震学が水分化され,蛇形化した前弓マントルのを明らかにし,地震の破裂限界に影響を与えています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- 地震学 地震学とは
- テクトニクス (地質学) とは
背景:
- 潜水板は揮発性物質を輸送し,マントルのの融解と弧マグマティズムを引き起こします.
- フロアークマントルのは,通常,アステノスフィアの流れのために,バックアーク領域よりも涼しいと考えられています.
- マントルのの構造を理解することは,弧マグマティズムと地震の危険性を説明するために重要です.
研究 の 目的:
- カスカディア南部の潜水地帯のマントルケイン構造を調査する.
- 前弓のマントルの物理的状態と構成を特定するために.
- フォアアークマントルの性質が地震性とマントルの流れに及ぼす影響を評価する.
主な方法:
- 散らばったテレシーミック波の分析.
- 広帯域地震計の密集したポータブル配列の展開.
- 地震速度の解釈とモホの構造.
主要な成果:
- 寒い前弓のマントルで非常に低いシャー波速度を発見した.
- 異常な"逆転した"大陸のモホー構造を特定した.
- 高度に水分化され,蛇形化した前弓マントル領域の証拠.
結論:
- カスカディア南部の前弓マントルのは,水分を大幅に吸収し,蛇形化しています.
- この蛇形化は,潜水地帯の熱学および地質学モデルと一致しています.
- 蛇形化した材料の強度が低いため,地震の破裂限界とマントルの流れの動態を制御する可能性がある.
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