東南極の氷床が底部から凍結することで,広く持続的に厚くなっている
Robin E Bell1, Fausto Ferraccioli, Timothy T Creyts
1Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA. robinb@ldeo.columbia.edu
Science (New York, N.Y.)
|March 10, 2011
まとめ
広範囲に広がる凍結は,東南極の下にある.
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.
- 気候科学 気候科学
背景:
- 氷床の成長は,主に表面上の雪の蓄積によって引き起こされます.
- 亜氷河過程は,氷床の動態に大きな影響を及ぼします.
- 基礎氷の形成を理解することは,氷床の正確なモデリングに不可欠です.
研究 の 目的:
- 東南極における基礎凍結の範囲と影響を調査する.
- 氷床下氷の形成を駆動するメカニズムを分析する.
- 凍結が氷床の質量バランスと動態にどのように影響するか評価する.
主な方法:
- 国際極地年における空気地質物理学調査.
- 氷床の底層の組成と厚さの分析.
- 氷床下水の行動と氷の形成のモデリング.
主要な成果:
- ドームAの下の氷床のベース面積の24%は凍結の証拠を示しています.
- いくつかの地域では,基礎凍結が氷の厚さの50%までを占めています.
- 凍結は,山頂や谷壁の近くの氷河下の水の冷却と超冷却によるものです.
結論:
- 基礎凍結は,東南極の大量再分配を推進する重要なプロセスです.
- 凍結は氷のレオロギーを変化させ,氷床を上向きに曲げ,気候アーカイブに影響を与えます.
- 現在の氷床モデルでは,基礎凍結が氷の流れに及ぼす影響が完全に捉えられていない可能性があります.
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