Mass transport by active rockglaciers in the Khumbu Himalaya

This paper investigates the talus transport and geomorphic work accomplished by active rockglaciers in the Khumbu Himalaya, Nepal. Active rockglaciers are responsible for a considerable amount of horizontal and vertical sediment movement in this area. Rates of sediment displacement are in the order of 7.1·106 m t yr−1 km−2. The most effective mechanism of sediment transport, however, is a debris-covered glacier with rates of 1.2·107 m t yr−1 km−2. A comparison with geomorphic work accomplished by active rockglaciers in the Swiss Alps shows that geomorphic effectiveness exceeds the one determined in the Khumbu Himalaya. Rockglaciers, debris-covered glaciers, and rockfall amount to a total of geomorphic work two orders of magnitude higher than similar phenomena in the Rocky Mountains of Colorado. Active tectonics, recent glacier activity, and climatic conditions specific to this region are possible explanations for this difference.