Untersee (Antarctica)

Submarine
Geographical location	Otto von Gruber Mountains , Queen Maud Land , East Antarctica
Tributaries	from the Anuchin Glacier
Data
Coordinates	71 ° 20 ′ 0 ″  S , 13 ° 27 ′ 0 ″  E Coordinates: 71 ° 20 ′ 0 ″  S , 13 ° 27 ′ 0 ″  E
Altitude above sea level	563  m
surface	11.4 km²
length	6.5 km
width	2.5 km
Maximum depth	169 m
Catchment area	241 km²

The Untersee ( English Lake Unter-See ) is a year-round frozen lake in East Antarctica .

location

The lake is located on the northern edge of the Otto von Gruber Mountains in the central Queen Maud Land . In addition to the Untersee, on the northeastern edge of the Otto von Gruber Mountains, there is the smaller and higher-lying Obersee .

description

The lake is about 6.5 km long, 2.5 km wide and permanently covered with ice, which in summer has an average thickness of 3.0 m. With a depth of 169 m and a surface of 11.4 km², the Untersee is one of the largest freshwater lakes in the Antarctic.

The Untersee is enclosed in a semicircle in the east, south and west by mountains of the Otto von Gruber Mountains, the Ritscher summit ( 2810  m ), the Mentzelberg and the Zimmermannberg . The valley, which is open to the north, is bounded by the Anutschin Glacier , whose meltwater feeds the Untersee. The barrier formed by the Anutschin Glacier dams the lower lake, which has no outflow. Water is only lost through evaporation and ablation of the ice cover.

The upper 70 m of the lake water has a high pH value between 9.8 and 12.1. There is supersaturation with dissolved oxygen (150%) and very low primary production . The water temperature is consistently below 1  ° C . The lake's sediments produce more methane than any other natural aquatic system on our planet.

history

The lake was discovered by the German Antarctic Expedition in 1938/39 under the direction of Alfred Ritscher , documented with the help of aerial photographs and named under the sea. The lake was reached for the first time by the 14th Soviet Antarctic Expedition in January / February 1969, during which the first investigations of the water body were carried out.

Astrobiological expedition

2008/2009 took advantage of an international expedition led by the astrobiologists Richard Hoover from the Marshall Space Flight Center of NASA the lake as a testing ground for the search for models of primitive extraterrestrial life . The conditions on and in the lake imitate the conditions suspected on Mars , the comets and the icy, methane-rich moons of Jupiter or Saturn . “The lake is as alkaline as strong bleaches and disinfectants . If we find extremophilic organisms in the submarine, it has far-reaching effects. This will help us to decide where to look for life on other planets and how to recognize extraterrestrial life if we actually find it, ”said Hoover in February 2008. In 2010, Hoover and the University of Innsbruck examined samples from the lake. The following year, he and his team returned to the Untersee to further investigate the conical stromatolites found there (only shortly before leaving the lake in 2008) . Stromatholites are formed as a result of the growth and metabolism of microorganisms in water.

See also

• Lake Vostok

literature

• Alfred Ritscher: Scientific and aeronautical results of the German Antarctic Expedition 1938/39 . Koehler & Amelang, Leipzig 1942, p. 1-304 .
• Markus Julius Schwab: Reconstruction of the late Quaternary climate and environmental history of the Schirmacher Oasis and the Wohlthat Massif . In: Reports on polar research . tape 293 . Bremerhaven 1998, p. 1-128 .

Web links

• Lake Unter-See in the Geographic Names Information System of the United States Geological Survey
• NASA Scientist Leads International Expedition to Antarctica in Search of Extreme Organisms
• Map of the Otto von Gruber Mountains with the location of the Untersee (PDF file; 269 kB)

Individual evidence

1. ^ Wand et al., "Evidence for physical and chemical stratification in Lake Untersee (central Dronning Maud Land, East Antarctica" Antarctic Science, Vol. 9 (1), pp. 43-45, 1997)
2. ↑ Federal Agency for Cartography and Geodesy, Directory of German Geographical Names of the Antarctic ( Memento of the original of July 3, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
3. ↑ Dmitri Nikolajewitsch Anutschin ( 1843-1923 ), Russian anthropologist, archaeologist, ethnographer and geographer
4. ^ "Relationship between ice cover, hydrology and sedimentation of Lake Untersee (East Antarctica) - a key to the Holocene climate reconstruction" Eos Trans. AGU, 81 (48), Fall Meet. Suppl., 2000
5. ↑ ^{a b} Hoover et al. (July 2, 2008) Extremophile Hunt Begins Science @ NASA ( Memento of the original from March 23, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (accessed March 19, 2008) 
6. ↑ homepage Tawani 2008 International Antarctic Expedition
7. ↑ Richard Hoover (NASA) visits the Aouda.X Suitlab. OeWF , November 29, 2010, accessed October 18, 2014 . 
8. ↑ Lake Untersee, Antarctica. Astrobiology Magazine, March 19, 2012, accessed October 18, 2014 .