ハワイの波の形から非線形マントルのレオロギーを推論する
N Asaadi1, N M Ribe, F Sobouti
1Institute for Advanced Studies in Basic Sciences, Zanjan 45137-66731, Iran. n_asaadi@iasbs.ac.ir
Nature
|May 13, 2011
まとめ
マントルプルームの海底の地形は,岩の支配的な変形を示している. ディスロケーション・クリップではなく,拡散・クリップがハワイの膨張を最もよく説明し,マントルのリオロギーと溶岩源の組成を示している.
科学分野:
- 地質物理学 地質物理学とは地質物理学です.
- ジオダイナミクスは地力学です.
- ミネラル物理学 ミネラル物理学
背景:
- マントルのコンベクションは浮力力によって駆動され,岩石リオロギーによって制御されます.
- 岩石は,拡散クリープ (線形張力-張力) または脱位クリープ (非線形) によって変形します.
- マントル全体で支配的な変形メカニズムを特定することは,極めて重要ですが,挑戦的です.
研究 の 目的:
- マントルの変形メカニズムが地表の地球物理データから推論できる地域を特定する.
- 拡散と変位のクリープを区別するための新しい観測可能な量を開発する.
主な方法:
- マントルの羽根から異常な海底の地形 (膨張) の下流の崩壊速度を分析する.
- 観測されたハワイの膨張地形を,流体力学モデルからの予測と比較する.
- オリヴィンとクリノピロキセンの実験室の変形データを用いて.
主要な成果:
- 膨張崩壊の速度は,ストレス-ストレスの指数と直接関連しており,クリープメカニズムを差異化しています.
- ハワイのスウェル・トポグラフィは,拡散・クリップによって説明が不十分である.
- ハワイの膨張を正確にモデル化するために,変位クリップリオロジーは必要です.
結論:
- 海底の地形は,マントルのレオロジーに地質学的制約を与える.
- 脱位クリープは,ハワイの羽根の支配的な変形メカニズムです.
- ハワイの溶岩源には,オリヴィンおよび/またはクリノピロキセンが含まれており,変位クリープによって変形しています.
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