カムチャツカ半島の近年の氷河質量収支変動と気候変動復元

Abstract

More than 400 glaciers exist in the mountains of Kamchatka Peninsula and they constitute the southern boundary of present-day glacierization along the eastern coast of the Eurasian continent. The mass balances of the glaciers are characterized by decadal and interdecadal oscillations, and they are closely related to those observed in the glaciers of Pacific North America. A negative relation was also found for the net accumulation timeseries reconstructed by ice cores from Ushkovsky Volcano, Kamchatka, and Mt. Logan, Canada, for the last 170 years. Because the oscillations of the net accumulation rate and the average annual δ 18O reconstructed from Ushkovsky-ice-core seem to be closely correlated with the so-called Pacific Decadal Oscillation (PDO) Index, it was suggested that the mass balances of the glaciers at both sides of the North Pacific had been affected not only by global warming trends but also by the interdecadal climate variability that had dominantly been occurring over the North Pacific.