浮力による氷床の急速な後退は,1日あたり数百メートル

Christine L Batchelor¹, Frazer D W Christie², Dag Ottesen³

¹School of Geography, Politics and Sociology, Newcastle University, Newcastle upon Tyne, UK. christine.batchelor@ncl.ac.uk.

Nature

|April 5, 2023

まとめ

氷床の地面線の退却率は海底の波紋の山脊を用いて定量化されました低傾斜の床で急速な後退パルスが発生し,以前の記録を超え,浮力による融解の脆弱性を強調しました.

科学分野:

氷河学と海洋地質学
古気象学と海面上昇の研究

背景:

海面上昇を理解するために氷床の接地線の縮小率は極めて重要です
海底の波紋は氷床の退却を長期にわたって記録していますが例は稀です
現存するデータは,将来の退却の動態と海面上昇への貢献の理解を制限しています.

研究の目的:

過去の氷床の退却率を定量化するために,多くの波紋の山脈をマッピングし分析します.
氷床の地形と接地線の後退のダイナミクスの関係を調査する.
特に南極で急速な浮力による後退の可能性を評価するためです

主な方法:

7,600以上の波紋の山脈を特定し,マップにしました.
ノルウェー・シェルフの中央の3万平方キロメートルにわたる山脊の距離を分析した.
現在の気候の強制下での潜在的後退率をモデル化するために,水静的原理を適用した.

主要な成果:

最後の脱氷期に記録された地平線の急速な後退 (55610 m/day)
過去の衛星観測と海洋地質学的記録を大幅に上回りました
低傾斜 (±1°) の氷床で最も高い撤退率が観察され,浮力による非接着性を示した.

結論:

氷床の平らな領域は急速な浮力による後退に非常に脆弱です
過去のノルウェーのシェルフの急速な後退は南極の氷床の行動の可能性を前例にしています
発見は,将来の海面上昇予測において,これらの動態を考慮する必要性を強調しています.

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