南極 の 氷棚 に 溶けた 水 が 大幅 に 移動 し て いる
Jonathan Kingslake1, Jeremy C Ely2, Indrani Das1
1Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA.
Nature
|April 21, 2017
まとめ
大規模な地表溶融水の排水が 南極に記録されており 大規模な池や小川が形成されています この現象は 何十年にもわたって観察され 温暖化が進む中で 氷の減少と海面上昇を 加速させる可能性があります
科学分野:
- * 氷河学と気候科学
- * 極地研究と冷凍圏研究
背景:
- * 氷床の表面の融水は池を形成し,氷床の崩壊と海面上昇を引き起こす可能性があります.
- * 現在の南極の氷床モデルでは 表面水の動きを無視し 溶けた水の影響を過小評価しています
- * 南極全域の表面水分とその進化を理解することは極めて重要ですが,限られています.
研究 の 目的:
- * 南極の氷床の表面溶融水の排水を量化し,理解する.
- * 表面排水システムと溶融池の規模と持続性を調査する.
- * 表面の排水が将来の氷の量減少に与える潜在的な影響を評価する.
主な方法:
- * 衛星画像の分析 (1973年以降)
- 航空写真 (1947年以降) の調査
- * 地表流,池,排水システムの特定と地図作成
主要な成果:
- * 南極の氷床全域に広がり,南緯85度,標高1300メートルまで広がっている.
- 地上排水システムは数十年にわたって存在し,長距離 (120 kmまで) に水を輸送しています.
- * 大規模な溶融池 (長さ80km) は,この広大な排水網の一部です.
結論:
- * 表面の溶けた水の排水は,南極の氷床の重要な長年の特徴です.
- * 温暖化に伴って地表の排水が増加すると 氷の減少と海面上昇が加速する可能性があります
- * 発見は,海面上昇を正確に予測するために,表面水理学を氷床モデルに組み込む必要性を強調しています.
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