2002 Volume 111 Issue 4 Pages 583-593
Mean annual air temperature (MAAT), mean annual surface temperature (MAST), bottom temperature of winter snow cover (BTS), and morphometric parameters of rock glaciers indicate the states of the rock glacier activities in the Yari-Hotaka mountain range, Northern Japanese Alps. The air temperature conditions at the Mountain Hut Minamidake suggest that this monitoring site belongs to the discontinuous permafrost zone. The BTS and MAST values at the North and South Okiretto rock glaciers indicate the occurrence of permafrost. BTS and MAST at the Tenguppara I rock glacier indicate the absence of permafrost. At the North Minamisawa rock glacier, MAST was slightly above 0 °C, accordingly degrading permafrost that possibly exists in this rock glacier. These rock glaciers are not moving at present, as inferred from the morphologic and vegetational characteristics of these rock glaciers. These results suggest that the North Minamisawa, North Okiretto, and South Okiretto rock glaciers are of the inactive type, and Tenguppara I rock glacier is of the fossil type. The other rock glaciers in this mountain range are of the fossil type, as inferred from collapse and subdued forms, and extensive vegetation cover.
