Last Glacial Snowline Altitude and Paleoclimate of the Eastern Asia

要旨

The lowest snowline altitude of the Last Glacial time was determined by using snowline data from previous studies and the author's observations which cover China, North and South Korea, the USSR, and Japan. The results are shown as a map of snowline altitude distribution over the whole of Eastern Asia, east of the 100°E longitude (Figure 1). Snowline gradient is steep along the margins of the Qinghai Plateau and along the Japan Sea coast of the Japanese islands. The snowline becomes higher toward the inland of the Asian continent, and also toward the inner part of the Pacific Ocean, both of which are occupied by a subtropical high. A relatively low snowline appears along the eastern margin of the Asian continent. This snowline“trough”stretches from Taiwan (Formosa) to southern Hokkaido through the northern part of the Northern Japanese Alps, where the snowline is 200-1, 000m lower than in the surrounding areas. The existence of this“trough”suggests that a relatively high level of winter precipitation was maintained during the Last Glacial as well as at present.

主題