TY - CHAP

T1 - Vostok Subglacial Lake

T2 - A Review of Geophysical Data Regarding Its Discovery and Topographic Setting

AU - Siegert, Martin J.

AU - Popov, Sergey

AU - Studinger, Michael

PY - 2013/3/26

Y1 - 2013/3/26

N2 - Vostok Subglacial Lake is the largest and best known sub-ice lake in Antarctica. The establishment of its water depth (>500 m) led to an appreciation that such environments may be habitats for life and could contain ancient records of ice sheet change, which catalyzed plans for exploration and research. Here we discuss geophysical data used to identify the lake and the likely physical, chemical, and biological processes that occur in it. The lake is more than 250 km long and around 80 km wide in one place. It lies beneath 4.2 to 3.7 km of ice and exists because background levels of geothermal heating are sufficient to warm the ice base to the pressure melting value. Seismic and gravity measurements show the lake has two distinct basins. The Vostok ice core extracted >200 m of ice accreted from the lake to the ice sheet base. Analysis of this ice has given valuable insights into the lake's biological and chemical setting. The inclination of the ice-water interface leads to differential basal melting in the north versus freezing in the south, which excites circulation and potential mixing of the water. The exact nature of circulation depends on hydrochemical properties, which are not known at this stage. The age of the subglacial lake is likely to be as old as the ice sheet (~14 Ma). The age of the water within the lake will be related to the age of the ice melting into it and the level of mixing. Rough estimates put that combined age as ~1 Ma.

AB - Vostok Subglacial Lake is the largest and best known sub-ice lake in Antarctica. The establishment of its water depth (>500 m) led to an appreciation that such environments may be habitats for life and could contain ancient records of ice sheet change, which catalyzed plans for exploration and research. Here we discuss geophysical data used to identify the lake and the likely physical, chemical, and biological processes that occur in it. The lake is more than 250 km long and around 80 km wide in one place. It lies beneath 4.2 to 3.7 km of ice and exists because background levels of geothermal heating are sufficient to warm the ice base to the pressure melting value. Seismic and gravity measurements show the lake has two distinct basins. The Vostok ice core extracted >200 m of ice accreted from the lake to the ice sheet base. Analysis of this ice has given valuable insights into the lake's biological and chemical setting. The inclination of the ice-water interface leads to differential basal melting in the north versus freezing in the south, which excites circulation and potential mixing of the water. The exact nature of circulation depends on hydrochemical properties, which are not known at this stage. The age of the subglacial lake is likely to be as old as the ice sheet (~14 Ma). The age of the water within the lake will be related to the age of the ice melting into it and the level of mixing. Rough estimates put that combined age as ~1 Ma.

KW - Antarctica

KW - Aquatic ecology-Antarctica

KW - Hydrology

KW - Icecore

KW - Radioechosounding

KW - Seismics

KW - Subglacial

KW - Subglacial lakes-Antarctica-Discovery and exploration

KW - Subglacial lakes-Antarctica-History

KW - Subglacial lakes-Polar regions-Discovery and exploration

KW - Subglacial lakes-Polar regions-History

UR - http://www.scopus.com/inward/record.url?scp=84951276230&partnerID=8YFLogxK

U2 - 10.1002/9781118670354.ch4

DO - 10.1002/9781118670354.ch4

M3 - Chapter

AN - SCOPUS:84951276230

SN - 9780875904825

SP - 45

EP - 60

BT - Antarctic Subglacial Aquatic Environments

PB - Wiley-Blackwell

ER -