Cryoconite
With Cryoconite is called the windverfrachteten mineral and organic emissions from forest fires and various exhaust gases such as from coal-fired plants , based on ice (z. B. glaciers ) or long lasting over snow fields in the high mountains accumulate. The dark layer of dust accelerates the melting of the ice or snow underneath due to the increased absorption of sunlight (see albedo ). This can create hollow shapes on the surface of the ice, known as cryoconite holes .
Since new dust is preferentially deposited in the resulting melt depressions, this leads to a self-reinforcing effect and, over time, kilometer-long gullies and often deep tubes are created, some of which eat their way down to the bottom of the glacier. It is not uncommon for the hollow forms to be filled with water during the summer and thus represent a habitat for cold-adapted microorganisms.
A main component of the Kryokonits is organic in nature such as, inter alia, (cyano) bacteria , algae and pollen ( pollen ), which can also be responsible for the dark to black color.
Etymology and history
The word cryoconite is derived from the Greek words κρύος [krýos] for "frost, ice" and κουία for powder, powder or dust.
The cryoconite and the consequences of its deposits were first described in 1870 by Adolf Erik Nordenskiöld , who discovered the phenomenon on his expeditions in the Greenland ice sheet.
literature
- What happens when the ice goes? In: World of Wonders. Compact. Volume 1, 2011, p. 12.
- Erna Aescht: Ciliates (Protozoa: Ciliophora) in the ice dust (cryoconite) of two glaciers in the Ötztal Alps (Tyrol, Austria) (PDF; 646 kB). In: Reports of the Natural Science-Medical Association in Innsbruck. Volume 92, December 2005, ISSN 0379-1416 , pp. 89-93.
Web links
Individual evidence
- ↑ Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard (1 Introduction), 2016
- ↑ Mark Jenkins: Changing Greenland - Melt Zone . In: National Geographic . June / July 2010.