西南極大陸の内部の氷流の方向の変化 西南極大陸の内部の氷流の方向の変化
Martin J Siegert1, Brian Welch, David Morse
1Centre for Polar Observation and Modelling, Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK. m.j.siegert@bristol.ac.uk
Science (New York, N.Y.)
|September 28, 2004
まとめ
バード・ステーションの近くのユニークな氷の折り合いは,西南極の過去の氷の流れの変化を示唆しています. この発見は,西南極中央部が,以前に考えられていたよりも,将来の氷河の流れの変化に対して,より敏感である可能性があることを示しています.
科学分野:
- 氷河学 氷河学とは
- 地質物理学 地質物理学とは地質物理学です.
- 南極研究南極研究
背景:
- 氷を貫通するレーダーは,西南極の氷床の下にある異常な折り畳み構造を明らかにしています.
- この折りたたみ構造の中で,異常に深いレベルで同期的な氷層が発見されています.
研究 の 目的:
- バード駅近くの氷の独特な折りたたみ構造の形成を調査します.
- 西南極における過去の氷河流動の動態を再構築する.
主な方法:
- 氷を貫通するレーダーデータの分析.
- 氷層のイソクロンと折り軸の向きの解釈.
- 氷の流れのダイナミクスのモデリング.
主要な成果:
- 大きな折りたたみ構造 (>50km長) が確認され,その軸は現在の氷の流れ方向に45度まで傾いている.
- 折りたたみの形成は,今日の氷の流れで説明するのは難しい.
- 約1500年前,折り軸に平行した過去流動状態は,観測された構造を説明することができます.
結論:
- 西南極の氷河流動の動態の過去の変化は,亜氷の構造から明らかである.
- これらの流れの変化は,南極海岸に近い氷河の流れの変化と関連している可能性があります.
- 中部西南極の氷は,以前よりも将来の変化に反応しやすくなり,海面上昇予測に影響を与える可能性があります.
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