マグマの侵入によって明らかになった中海の
Jean-Arthur Olive1, Göran Ekström2, W Roger Buck2
1Laboratoire de Géologie, CNRS - École Normale Supérieure - PSL University, Paris, France. olive@geologie.ens.fr.
Nature
|April 10, 2024
まとめ
中海の山脊の構造的な拡張は,山脊の側面の縮小によって逆転することができます. このプロセスは,逆転の地震によって証明され,海底の地形に影響を与え,拡張的な設定での地震活動を説明します.
科学分野:
- 地質学
- 構造学
- 地震学
背景:
- 中洋の山脊 (MORs) は,地質学的な拡張と石層板の分岐の主要な場所です.
- MORで形成された深い丘は 地球の海底の大部分をカバーしています
研究 の 目的:
- MORの拡張を相殺する構造的縮小の現象を調査する.
- 広域構造環境における逆転地震の発生を説明する.
主な方法:
- 中大西洋山脊とカールスバーグ山脊の近くの地震の分析
- リトスフィアの不屈と圧縮をシミュレートするための機械モデルの開発.
- アビサルの丘の地形に及ぼす影響を評価するバチメトリック分析.
主要な成果:
- MORで軸外で発生する逆欠陥地震を特定した.
- リトスフィアの不屈が自然に山脊の浅い圧縮につながることを実証した.
- マグマで満たされた断層は 圧縮ストレスを引き起こし 断層を逆転させる
- 通常の断層の逆再活性化により,アビッサルヒル幅が50%まで減少することが観察されました.
結論:
- 脊梁の側面の構造的縮小は,MORの軸延伸を部分的に逆転させる.
- この"不変"なメカニズムは 地球の海底構造に 大きく影響します
- エクステンショナルの環境で反転する地震の物理的な説明をします.
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