Lake Untersee

For other uses, see Untersee.

Lake Untersee
Untersee (German)
Lake Untersee in 1996
Location of Lake Untersee in Antarctica
Location of Lake Untersee in Antarctica
Lake Untersee
Location of Lake Untersee in Antarctica
LocationQueen Maud Land, Antarctica
Coordinates71°20′S 13°27′E / 71.333°S 13.450°E / -71.333; 13.450
Typeglacial
Etymology"Lower Lake" (from German "unter" [lower] + "see" [lake])
Basin countries(Antarctica)
Max. length6.5 kilometres (4.0 mi)
Max. width2.5 kilometres (1.6 mi)
Surface area11.4 square kilometres (4.4 sq mi)
Max. depth169 metres (554 ft)
Surface elevation563 metres (1,847 ft)
FrozenPermanently
ReferencesWand et al.[1]

Lake Untersee (German: Untersee, "Lower Lake") is the largest surface freshwater lake in the interior of the Gruber Mountains of central Queen Maud Land in East Antarctica. It is situated 90 kilometres (56 mi) to the southeast of the Schirmacher Oasis. The lake is approximately 6.5 kilometres (4.0 mi) long and 2.5 kilometres (1.6 mi) wide, with a surface area of 11.4 square kilometres (4.4 sq mi), and a maximum depth of 169 metres (554 ft). The lake is permanently covered with ice and is partly bounded by glacier ice.[2][3]

Lake Untersee is an unusual lake, with pH between 9.8 and 12.1,[1][4] dissolved oxygen at 150 per cent supersaturation, and very low primary production in the water column. Despite the high oxygen supersaturation in most of the lake, there is a small sub-basin at the southern end that is anoxic, and its sediments may have a higher methane concentration than those of any other known lake on Earth.[4][5] Much of the primary production is in microbial communities that grow on the floor of the lake as stromatolites.[6] The water temperature varies between 0.5 °C (32.9 °F) and 5 °C (41 °F) and the ice cover on the lake is 2–6 metres (6.6–19.7 ft) thick.[1][4] The ice cover may have persisted for over 100,000 years, and some scientists studying climate change fear significant environmental changes associated with global warming in the coming decades.[3] In the past, the water chemistry of the lake has been compared to Clorox.[7] However, the chemical activity of bleach is due to Cl− in addition to a pH that is higher than that measures in Lake Untersee, and Lake Untersee does not have high chlorine or chlorite concentrations.[1][4]

  1. ^ a b c d U. Wand; G. Schwarz; E. Bruggemann; K. Brauer (1997). "Evidence for physical and chemical stratification in Lake Untersee (central Dronning Maud Land, East Antarctica)". Antarctic Science. 9 (1): 4345. Bibcode:1997AntSc...9...43W. doi:10.1017/S0954102097000060.
  2. ^ W.-D. Hermichen; P. Kowski; U. Wand (1985). "Lake Untersee, a first isotope study of the largest freshwater lake in the interior of East Antarctica". Nature. 315 (6015): 131–3. Bibcode:1985Natur.315..131H. doi:10.1038/315131a0. S2CID 23843171.
  3. ^ a b "Antarctica's Lake Untersee and Global Warming". Kinohi Institute. Archived from the original on July 26, 2011. Retrieved November 26, 2010.
  4. ^ a b c d U. Wand; V. A. Samarkin; H.-M. Nitzsche; H.-W. Hubberten (2006). "Biogeochemistry of methane in the permanently ice-covered Lake Untersee, central Dronning Maud Land, East Antarctica". Limnology and Oceanography. 51 (2): 1180–1194. Bibcode:2006LimOc..51.1180W. doi:10.4319/lo.2006.51.2.1180.
  5. ^ "Extremophile Hunt Begins". NASA Science. February 7, 2008. Archived from the original on March 23, 2010. Retrieved April 21, 2011.
  6. ^ Andersen, DT; Sumner, DY; Hawes, I; Webster-Brown, J; Mckay, CP (2011). "Discovery of large conical stromatolites in Lake Untersee, Antarctica". Geobiology. 9 (3): 280–293. Bibcode:2011Gbio....9..280A. doi:10.1111/j.1472-4669.2011.00279.x. PMID 21504538.
  7. ^ "Extremophile Hunt Begins". Science News, NASA. February 7, 2008. Archived from the original on March 23, 2010. Retrieved November 26, 2010./