Mountain glaciation in Japan and Taiwan at the global Last Glacial Maximum

Abstract

Montane glaciation in Japan and Taiwan was maximal in MIS 3/4 and glacier extent at the global Last Glacial Maximum (LGM) was much more limited. Data from four areas in Japan and two in Taiwan, where the topographical and chronological positions of the terminal moraines are well determined and the chronology is controlled by radiocarbon, AMS and 10Be cosmogenic dates, are presented in this paper. Equilibrium line altitudes (ELAs) at global LGM are around 1500 m in the Hidaka Range, Hokkaido, 2500 m in the Northern Japanese Alps, 2700 m in the Central Japanese Alps, 2800 m in the Southern Japanese Alps in Japan, and 3300 m in northern Taiwan and 3500 m in central Taiwan. The ELAs are mostly determined by maximum discharge, accumulation–ablation area ratio (AAR) and glacier toe-and-headwall ratio (THAR) methods. The pattern of contours of ELAs indicates a strong influence of precipitation control on glacier development in this region. The ELA depression at global LGM in Japan was 1100–1300 m except in the northernmost part of the Northern Japanese Alps (only 400 m), where the present hypothetical ELA is extraordinarily low because of abundant snowfall. The ELA depression at global LGM in Taiwan is estimated at about 1100–1300 m without consideration of uplift.