パイン・アイランド氷河,南極の氷河の下の海域境界層に氷の融解をチャネリングした
T P Stanton1, W J Shaw, M Truffer
1Department of Oceanography, Naval Postgraduate School, Monterey, CA 93943, USA. stanton@nps.edu
まとめ
パイン・アイランド氷河の氷棚は,海洋温暖化により,下から溶けている. この研究は,ベースチャネルが氷棚の頂点を急速に溶かして,南極の氷床の安定性に影響を与えることを明らかにしています.
科学分野:
- 氷河学 氷河学とは
- 海洋学 海洋学とは
- 南極研究南極研究
背景:
- 氷棚は,氷河を支えるため,南極の氷床の安定性にとって非常に重要です.
- パインアイランド氷河 (Pine Island Glacier,PIG) は,西南極氷床の出口にある主要な氷河で,急速に薄れ,加速しています.
- 海洋の熱力強制は,氷床の弱まりの重要な要因である.
研究 の 目的:
- パイン・アイランド氷河の氷棚の下の海洋による融解プロセスを調査するために.
- アイスシェルフの薄まりにおけるベースチャネルの役割を理解するために.
- 西南極の氷床の安定性に対する基礎層の融解の影響を評価する.
主な方法:
- 氷床の地質学的調査.
- 長期海洋学機器の配置 氷床の下の空洞の掘削孔を通って長期海洋学機器の配置.
- 基礎運河内の融解速度の分析.
主要な成果:
- ベースチャネル内に浮力駆動の境界層が特定されました.
- 運河の頂上は,1日あたり0.06メートルという速度で急速に溶けていきます.
- 運河の側面に沿って,ほぼゼロに近い融解率が観察されました.
- 複雑なチャネルパターンは,パイン・アイランド氷河の氷棚に広がっています.
結論:
- ベースチャネルの融解は,パインアイランド氷河の氷棚の薄まりに大きく貢献しています.
- 海の温暖化による基礎運河の融解は,氷床の安定性を脅かしている.
- これらの融解過程を理解することは,将来の南極の氷の減少と海面上昇を予測するために不可欠です.
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