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南極氷床 : その変動と海洋との相互作用
杉山, 慎
Permalink : http://hdl.handle.net/2115/70333
JaLCDOI : 10.14943/lowtemsci.76.169
KEYWORDS : 氷床;棚氷;溢流氷河;棚氷底面融解;カービング;ice sheet;ice shelf;outlet glacier;subshelf melting;calving
Abstract
南極氷床は地球に存在する淡水の60％以上を蓄積し，巨大な淡水リザーバとしての役割を担っている．その変動は海水準，海洋循環，アルベド，地殻隆起など，地球の気候システムに大きな影響を与える．近年の観測技術の向上によって，この氷床が氷を失いつつあることが明らかになってきた．南極沿岸部において顕著な質量損失が報告されており，海洋の変化に影響を受けた棚氷と溢流氷河の縮退がその原因と考えられている．本稿では，南極氷床の特徴と地球環境に果たす役割，氷床変動のメカニズムについて概説した後，近年の氷床変動とそれを駆動する氷床・海洋相互作用について最近の知見を紹介する．
The Antarctic ice sheet stores ＞60% of freshwater on the earth, acting as a giant freshwater reservoir. Changes in the ice sheet give impact on the climate system of the earth by affecting sea level, ocean circulation, albedo and lithospheric uplift. Recently advanced observational techniques tell us that the Antarctic ice sheet is losing mass. Significant mass loss is reported from the coastal margins, implying the influence of ocean changes on the ice shelf and outlet glaciers. This contribution provides a general overview of the Antarctic ice sheet, and its dynamics and potential influence on the earthʼs climate system. Research results are introduced to outline the recent ice sheet mass change driven by the ice-sheet-ocean interactions.
The Antarctic ice sheet stores ＞60% of freshwater on the earth, acting as a giant freshwater reservoir. Changes in the ice sheet give impact on the climate system of the earth by affecting sea level, ocean circulation, albedo and lithospheric uplift. Recently advanced observational techniques tell us that the Antarctic ice sheet is losing mass. Significant mass loss is reported from the coastal margins, implying the influence of ocean changes on the ice shelf and outlet glaciers. This contribution provides a general overview of the Antarctic ice sheet, and its dynamics and potential influence on the earthʼs climate system. Research results are introduced to outline the recent ice sheet mass change driven by the ice-sheet-ocean interactions.
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