Bulletin of Glaciological Research, 2001, 18, 65-69
Characteristics of cryoconite (surface dust on glaciers) and surface albedo of a Patagonian glacier, Tyndall Glacier, Southern Patagonia Icefield
Nozomu Takeuchi1, Shiro Kohshima2, Takayuki SHIRAIWA3, Keiji KUBOTA3
1.Frontier Observational Research System for Global Change, International Arctic Research Center, University of Alaska Fairbanks, 930 Koyukuk Dr. P.O.Box 757335 Fairbanks AK 99775-7335, U.S.A.
2.Basic biology, Faculty of Bioscience and Biotechnology, (c/o Faculty of Science), Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
3.Institute of Low Temperature Science, Hokkaido University,
Kita-19, Nishi-8, Kita-ku, Sappro 060-0819, Japan.
Characteristics of cryoconite (surface dust on glaciers) and the surface albedo were investigated on a Patagonian glacier (Tyndall Glacier in Southern Patagonia Icefield, Chile). The amount of the cryoconite on the surface of the ablation area (14 - 71 g m-2, mean: 47 g m-2 in dry weight) was much smaller as compared to those reported from other region such as Himalaya (50 - 900 g m-2, mean: 300 g m-2). The percentage of organic matter in the cryoconite (0.6% - 2.7%, mean: 1.8% in dry weight) was also smaller compared to those of glaciers in other parts of the world. Microscopic observation revealed that the cryoconite consisted of much mineral particles, amorphous organic matter, and small amount of snow algae. Cryoconite with granular structure, which is generally formed on the glaciers by algal activity in Himalayas, Tibet, and Arctic, was not observed. The surface albedo ranged from 0.32 to 0.65 (mean: 0.45), which is almost equivalent to albedo of clean bare ice surface. Our results indicate that the effect of cryoconite and biological activities on the surface albedo in this glacier is very small due to the small amount of the cryoconite and small algal production.