グリーンランドの氷床の表面の融解が増加する根底流水システムの反応
T Meierbachtol1, J Harper, N Humphrey
1Department of Geosciences, the University of Montana, Missoula, MT 59812, USA. toby.meierbachtol@umontana.edu
まとめ
表面の融水は,基礎水圧に影響することで,グリーンランドの氷床の移動に影響します. 現在のモデルは,内陸水理学が氷河流動力学にどのように影響を与えるかを完全に捉えていない可能性があります.
科学分野:
- 氷河学 氷河学とは
- 水文学 水文学とは
- 地球科学 地球科学 地球科学
背景:
- グリーンランドの氷床に届く地表の融水は,基礎運動に不可欠です.
- 氷床の滑り速度は,氷と床の結合によって決定され,亜氷河水文系の影響を受けます.
- グリーンランドの基礎水文学の既存のモデルは,しばしば山の氷河の研究に基づいています.
研究 の 目的:
- グリーンランドの氷床の下の基礎水圧と水文システムの構成を調査する.
- 溶融水の排出を内陸に輸送するための氷床下水力学的システムの能力を評価する.
- グリーンランドの氷床に,山の氷河から派生した水文モデルの適用性を評価する.
主な方法:
- グリーンランドの氷床床までの4箇所の断面に23の掘削孔を用いたインシトゥー観測.
- リアルな氷床の幾何学を組み込んだ数値分析.
- 基礎水圧と氷壁の融解率の分析.
主要な成果:
- 観測された基礎水圧は,深い氷の下の内陸水流管の発展に不利である.
- 氷壁のゆっくりとした融解は,管の成長を制限し,融水排出量の増加を管理する能力を制限します.
- この発見は,現在の概念モデルが,主に氷床の縁付近の消去地帯に適用可能であることを示唆しています.
結論:
- 深い内陸のグリーンランド氷の下の亜氷河水学システムは,大量の融水量を効果的に輸送できない可能性があります.
- 亜氷河管の成長と機能は,氷床の幾何学と融解のダイナミクスによって制限されています.
- グリーンランドの氷床のユニークな特徴を考慮して,グリーンランドの基礎水文学の見直しが必要である.
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