ロス氷河流の正質量バランス,西南極
1Jet Propulsion Laboratory, California Institute of Technology, Mailstop 300-235, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. ian@radar-sci.jpl.nasa.gov
Science (New York, N.Y.)
|January 19, 2002
まとめ
西南極のロス氷河に関する新しい研究は,氷床の減少ではなく,大幅な増加を明らかにしています. 氷床の質量バランスのこの再評価は,これらの重要な南極の氷河のホロセンの撤退の潜在的な終わりを示唆しています.
科学分野:
- 氷河学 氷河学とは
- 気候科学 気候科学
- リモートセンシング (リモートセンサー)
背景:
- 南極の氷床の質量バランスは,世界の海面上昇を理解するために重要です.
- 以前の推定では,ロス氷河の質量バランスが負であることを示唆しており,これは氷の減少を示唆している.
研究 の 目的:
- 先進的な氷の流れ速度測定を用いて,ロス氷河の質量バランスを再評価する.
- これらの主要な西南極氷河の安定性における現在の状態と最近の変化を調査するために.
主な方法:
- 合成開口レーダー (SAR) を使用して,氷の流れ速度を正確に測定しました.
- 速度のデータを分析し,氷の量の変化を計算し,質量バランスを決定します.
主要な成果:
- 強力な証拠は,氷床の全体的な成長が年間26.8ギガトン+であることを示しており,これは,赤字に関する以前の推定と矛盾しています.
- 観測された平均濃縮率は,蓄積率の約25%で,主に氷河流Cで観測された.
- ウィランス氷河流は,減速による大量減量の予想に反して,ほぼバランスをとっています.
結論:
- ロス氷河流は現在,質量が増えているので,質量バランスが正であることを示唆しています.
- この成長は,ホロセーン時代に観察された長期の撤退からの移行を意味するかもしれません.
- この発見は,南極の氷河の流れのダイナミックな性質と,最新の観測データの重要性を強調しています.
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