Some Periglacial Morphology in the Sagarmatha (Everest) Region, Khumbu Himal

Glaciological Expedition to Nepal, Contribution No. 24

Abstract

The periglacial morphology in the Sagarmatha region, Khumbu Himal, was surveyed and mapped. Below the snow line most of the mountain slopes consist of rock walls, talus, and block slopes. The rock detritus is produced by frost action and other weathering processes and transported downward as rock falls. Rock glaciers and block streams are produced where the periglacial process acts strongly and not only the rock debris but also snow and ice concentrate. The block slopes occupy the gentle valley side slopes which are covered with coarse and angular rock fragments mass-wasting from bed rock. Vegetated patterned ground develops over a large area because dense winter freezing acts over the vegetation fed by monsoon rain and high temperature in summer. Sorted patterned ground is rare in the region and is found only at the bare ground area adjacent to the glaciers and the bottoms of ponds. Some forms, such as debris islands, rock glaciers, and block slopes in the region are inactive at present.