Historical geomorphology on glacial and periglacial slopes in the Japanese Alps using field data and digital elevation models

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K01215
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geography
• Research Institution: University of Tsukuba
• Principal Investigator: Ikeda Atsushi 筑波大学, 生命環境系, 准教授 (60431657)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 氷食谷 / 形状解析 / 最終氷期 / 永久凍土 / 地温観測 / 岩石氷河

Outline of Final Research Achievements

In the central Honshu, the glacier distribution during the last glacial period and the lower boundary of the present permafrost were examined. First, we examined whether the particle shapes of glacial and landslide deposits could be mathematically distinguished, but there was no significant difference. On the other hand, the maximum distribution of glacial valleys, which were extracted from digital elevation models, is much smaller in the northern Hida Range than the results of conventional subjective interpretation. In addition, the temperature on the lower boundary of permafrost on Mt. Fuji was higher than that of Mt. Daisetsu, Hokkaido. Typhoon rainfall shifted the lower boundary upward in Honshu.

Free Research Field

地形学

Academic Significance and Societal Importance of the Research Achievements

一般に古環境研究は，試料採取と分析能力の専門性が高まることで大きく発展しているが，本研究の場合，古気候を代替する試料に乏しい山岳地について，現在の観測研究（例えば，現成氷河の運動や永久凍土の観測結果）を背景に推定していくことで新規性のある古環境復元を試みた。そうして得られた山岳地の古環境情報は，低地で得られた定量的な古環境指標や，いずれコンピュータシミュレーションによって詳細に復元されるであろう過去の気候値と対比可能なデータとなる。そのうえで山岳地の生態系変動などを議論するときに有用な情報となると考えられた。