過去 750 万 年 に わたっ て 持続 し て 動 的 な 東 グリーンランド の 氷床
Paul R Bierman1, Jeremy D Shakun2, Lee B Corbett1
1Department of Geology and Rubenstein School of the Environment and Natural Resources, University of Vermont, Burlington, Vermont 05405, USA.
Nature
|December 9, 2016
まとめ
東グリーンランド氷床は数百万年もの間存在し,プレイストセンの初期に動的変化を示し,後に広範囲に氷が覆われた. これは過去の温暖な期間の完全な脱氷のアイデアに挑戦しています.
科学分野:
- 古代気候学
- 氷河学
- 海洋地化学
背景:
- 過去の氷床の振る舞いを理解することは 将来の海面上昇を予測するのに 極めて重要です
- 古代の氷床の記録は 侵食されていて 年代が悪いことが多いのです
- 海の沈殿物は氷床の変化を より連続的に記録しています
研究 の 目的:
- 過去750万年の東グリーンランド氷床の歴史を 再構築する
- 重要な気候変化の際に氷床の動態を調査する.
- 過去の氷河期間の完全な脱氷に関する仮定に異議を唱えるため
主な方法:
- 海洋沈殿物のベリリウムとアルミニウム同位体 (10Beと26Al) の分析
- 氷河の侵食と沈殿物の移動を追跡するために宇宙核を活用する.
- 氷床の範囲と活動を推測する
主要な成果:
- 東グリーンランド氷床は 少なくとも750万年もの間 継続的に存在しています
- 氷の覆いはプレイストセンの初期に動的であり,プレイストセンの中期から後半にかけて広範囲に広がった.
- 同位体データは主要な気候変動と相関し,氷床の振る舞いの変化を示しています.
結論:
- この研究は,東グリーンランドで数百万年にわたる完全かつ広範な脱氷の証拠を提供します.
- 過去の氷床の振る舞いは複雑で多様でした 特に気候の変化の間です
- 氷河間の氷床の動態に関する理解を深めることができるでしょう.
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