Late quaternary equilibrium line altitude in the kiso mountain range, central Japan

Abstract

Geomorphological equilibrium line altitude (ELAg), as defined by steady-state equilibrium line altitude based on geomorphological method, has been used to reconstruct Last Glacial palaeoclimate. However, the ELAg is influenced not only by temperature, but also by other factors. This paper discusses factors affecting Last Glacial ELAg in the Kiso mountain range, central Japan. The weathering-rind thickness of gravel was used for dating moraines. The dating results have shown that glaciers advanced at the Last Glacial Maximum and the Younger Dryas stages. The ELAg for each stage was reconstructed based on the Accumulation-Area-Ratio method (AAR=0.6). The results indicate that the ELAg of each reconstructed glacier was affected not only by temperature but also by the altitude of mountain ridges. Although some previous studies have reconstructed palaeoclimate based on the ELAg, the results of the present study cast doubt on such reconstruction. For better reconstruction, the effects of temperature on the ELAg should be separated from those of topographic factors.