Lake Vostok Stays Liquid Under 4 Kilometers of Ice as Pressure Lowers Freezing Point
Updated
Updated · spacedaily.com · Jul 27
Lake Vostok Stays Liquid Under 4 Kilometers of Ice as Pressure Lowers Freezing Point
2 articles · Updated · spacedaily.com · Jul 27
Summary
Nearly 4 kilometers of Antarctic ice above Lake Vostok acts as insulation, while weak geothermal heat from below keeps the lake’s base at its melting point despite surface temperatures near minus 55C.
Roughly 34 megapascals of pressure at the lake roof lower freshwater’s melting point to about minus 2.5C to minus 3C, allowing the water to remain liquid without requiring high salinity.
Radar, seismic and borehole evidence show the system is dynamic: thicker-ice zones melt, shallower zones freeze, and more than 200 meters of accretion ice has formed beneath the moving ice sheet.
About 14,000 square kilometers in area and comparable in scale to Lake Ontario, the subglacial lake is likely deeper and may hold more water, though its exact shape and volume remain model-dependent.
An estimated 15 million years of ice cover make Lake Vostok a key analogue for icy moons, but contamination risks since drilling reached the interface in 2012 still limit firm biological conclusions.