Cryoconite

Abstract

Cryoconite is dark-colored sediment on glacier surface, and usually deposited at the bottom of water-filled cylindrical pits, called cryoconite holes. Cryoconite and cryoconite holes can be commonly observed from polar ice sheets to low-latitude mountain glaciers in the world. Cryoconite consists of mineral particles supplied from surrounding ground by wind, biogenic organic matter produced by microbes living on the glacial surface, and also micrometeorites in some glaciers. These constituents are usually conglomerated into small granules, called cryoconite granules. Abundant microbes in cryoconite indicate that glaciers are biologically active environments. Thus, it is important to study cryoconite to understand the ecology of organisms in such cold environments. Furthermore, dynamics of cryoconite holes are strongly related with physical conditions on glacier surface and can affect total ablation of glaciers. Thus, physical process of cryoconite holes is important to evaluate mass balance of glaciers. The information on cryoconite and holes, however, is still limited on particular glaciers, further studies, therefore, are necessary to understand them both biologically and physically on worldwide glaciers.