| Summary: | 北部北太平洋の両岸にそびえる高山には寒冷氷河が発達し、過去数百年から千年程度の古気候・古環境情報が冷凍保存されている。カムチャッカ半島のウシュコフスキー山、アメリカ合衆国アラスカ州のランゲル山、カナダ・ユーコン準州のローガン山の3地点で全長200m を越す雪氷コアを掘削し、その物理特性を明らかにし、これらの3本のコアが有力な気候代替記録を有している可能性を示した。特にウシュコフスキー山のコアからは、過去 170年間の気温と降水量に関する気候代替記録を得た。また、既存のローガン山の気候代替記録とウシュコフスキー山の記録を比較したところ、両者には負の相関が認められ、北太平洋十年振動(PDO)との関連が示唆された。 Three indepewndent ice cores were recently drilled at Ushkovsky Volcano in Kamchatka, Russia, Mount Wrangell in Alaska, and Mount Logan King Col in Canada. Detailed analyses of the temperature and density profiles of the three cores suggest that the three sampled glaciers are cold glaciers and therefore store reliable paleo-climate information that spans the past several hundreds to a thousand years. A negative relation was found for the net accumulation time-series reconstructed for the past 170 years from the ice cores recoverd from Ushkovsky Volcano and Mount Logan. As the oscillations in the net accumulation rate and the average annual δ^18O reconstructed from the Ushkovsky ice core appear to be closely correlated with the so-called Pacific Decadal Oscillation (PDO) Index, it was suggested that the mass balances of the glaciers on both sides of the northern North Pacific were affected not only by a global warming trend since the Little Ice Age but also by inter-decadal climate variability that had occured dominantly over the North Pacific. 1章 10年～100年スケールの気候変動の観測, 気候復元とモニタリング
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