人類進化と新生代後期の環境変化 日本海沿岸，北陸地方における最終氷期‐完新世変動に伴う気温と季節性の変動の復元

Abstract

Thermal climate changes from the Last Glacial through to the present on the coastal area of Hokuriku region, Japan, along the Japan Sea were quantitatively reconstructed using the pollen profile from Lake Mikata (Fukui Prefecture, central Japan) sediment core, Japanese surface pollen dataset, and Japanese meteorological dataset. The best-modern-analogues method firstly proposed by Guiot (1990) and recently revised/improved by Nakagawa et al. (2002) was adopted to infer climate indices from fossil pollen data. The change in seasonality is especially highlighted in this paper. Our results show that the seasonality (summer to winter temperature anomaly) during the Last Glacial was about 3 e bigger than the present. This may reflect that, given that the sea level during the Last Glacial was much lower than the present, the heat transport to the Japan Sea by the Tsushima current was not active and the coastal area along the Japan Sea was more efficiently cooled down by the winter monsoon.