地滑りと河川による侵食の間のフィードバックによってスケールされた山脈の寿命
David L Egholm1, Mads F Knudsen, Mike Sandiford
1Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, 8000 Aarhus C, Denmark. david@geo.au.dk
Nature
|June 28, 2013
まとめ
山脈の救済は,河川の浸食と滑落の間のフィードバックループによって保たれています. この結合は,古代の山々が,構造的活動が止まった後も長く存続する理由を説明しています.
科学分野:
- ジオモルフォロジー ジオモルフォロジー
- テクトニクス (地質学) とは
- 侵食のダイナミクス
背景:
- 活発な山脈における高浸食率と,古代の山脈における地形保全の調和は,重要な地形学的課題である.
- 河川浸食と堆積物輸送は,山脈の寿命の主要な要因である.
- 侵食率を制御する要因と,その構造的活動との関連が議論されている.
研究 の 目的:
- 山脈の侵食を制御する際の岩床川の切断と山崩との関係を調査する.
- 構造的に活発な山脈と不活発な山脈の間の侵食率の変動を説明するために.
- 山岳地形を長期的に保存するための物理的メカニズムを提供すること.
主な方法:
- 計算シミュレーションを用いて,河川の切断と滑坡の相互作用をモデル化しました.
- この研究では,岩床川の切断と地滑り頻度の双方向的な結合を分析した.
- モデルでは,沈殿物の流出と河川の容量を通して,滑落が河川の侵食にどのように影響するかを調査した.
主要な成果:
- 河川の切断と地滑りとの双方向的な結合は,侵食の動態にとって決定的に重要であると特定されました.
- 地滑りが,輸送能力を圧倒することによって川床を保護したり,荒廃性沈殿物を放出することによって侵食を加速したりすることができます.
- カップリングメカニズムは,活動的な山脈と非活動的な山脈の侵食率に根本的に異なる影響を及ぼします.
結論:
- 川の切断と地滑りとの相互作用は,山脈の持続的なレリーフの妥当な説明を提供します.
- この結合メカニズムは,古代のオロゲンベルトにおける重要なリリーフの長期保存を説明するのに役立ちます.
- この発見は,多様な構造的環境における景観の進化を理解するための物理的基礎を提供します.
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