まとめ
1984年,フラム海峡から出る北極流域の氷のほとんどは,多年の氷であり,しばしば変形していました. 研究者は,雪の深さ,コアの硬さ,塩分度によって氷の種類を区別し,5年までの年齢を発見しました.
科学分野:
- 北極の海洋学 北極の海洋学
- 海氷の物理学 海氷の物理学
- 氷河学 氷河学とは
背景:
- フラム海峡は,北極海氷の重要な出口点です.
- 北極圏から出る海氷の特徴を理解することは,気候研究にとって不可欠です.
- 1年目の氷より古く,厚く,多年の氷は,北極の生態系において重要な役割を果たしています.
研究 の 目的:
- 1984年6月~7月にフラム海峡を通って北極盆地から出る海氷の特徴を記述する.
- 物理的性質に基づいて,1年目の氷と多年目の氷を区別する.
- 観測された多年氷の年齢を推定する.
主な方法:
- フリーボードの氷の分析,厚さ,塩分.
- 氷床の雪の覆い深さの測定.
- 氷の核のペトログラフィックおよび塩分特性に関する調査.
- 氷のコアの硬さと透明性の視覚検査.
主要な成果:
- フラム海峡から出る氷の推定84%は,多年氷だった.
- この多年の氷の重要な部分は変形 (斜面) した.
- 雪の覆いの深さ,コアの硬さ,透明性は,多年氷と1年氷を区別するための効果的な指標でした.
- 氷の核の分析によると,多年の氷床は4~5年まで老化していた.
結論:
- 多年氷は,フラム海峡を通る北極流域の流出を支配しています.
- 変形は,この流出する多年の氷の共通の特徴です.
- シンプルな表面とコア測定は,多年の氷を効果的に識別し,大規模な氷の特徴づけに役立ちます.
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