マントルの流れは,海洋プレートの沈下を駆動する
1Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, 237-0061, Japan. adam@uevora.pt
まとめ
海底の深さは主に石層の年齢だけでなく,マントルの流れによって制御されます. この研究は,深さの変動が山脊からの距離の平方根に従っていることを明らかにし,以前の冷却モデルに挑戦しています.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- 海洋学 海洋学 海洋学
- プレート・テクトニクス (プレート・テクトニクス)
背景:
- 海底沈殿は,伝統的に,石層の被動的な冷却と,年齢とともに密集化に起因する.
- リトスフィアの構造は,マントルのコンベクションと根本的に結びついているので,流動のダイナミクスが重要であることを示唆しています.
研究 の 目的:
- 底層のマントル流が石層構造と海底の深さに及ぼす影響を調査する.
- 海底の深さ,石層の年齢,マントルの動力学との関係を再評価する.
主な方法:
- マントルの流れ経路を表す軌跡に沿った海底の深さの変動の分析.
- 界層方程式を応用して,石層の冷却と沈下をモデル化.
主要な成果:
- 海底の深さは,プレート全体にわたって,中海のから距離の平方根で一貫して増加します.
- 観測された深さの変動はマントルの流れ予測と一致し,石層の底部に追加の熱源を必要としない.
- このモデルは,山脊からの距離と深さの間の連続的な関係を示し,以前の"平ら化"の観測を否定しています.
結論:
- マントルの流れのダイナミクスは,単なる石層の年齢ではなく,海底沈没の主要な要因です.
- 確立された境界層冷却モデルは,マントルの流れ線に沿って海底の深さを正確に予測します.
- この研究は,海洋石層の進化とそのマントルのコンベクションとの関係に関する私たちの理解を洗練します.
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