sentences:  The average water temperature is calculated to be around ; it remains liquid below the normal freezing point because of high pressure from the weight of the ice above it.Geothermal heat from the Earth's interior may warm the bottom of the lake, while the ice sheet itself insulates the lake from cold temperatures on the surface.Lake Vostok is an oligotrophic extreme environment, one that is expected to be supersaturated with nitrogen and oxygen, measuring of nitrogen and oxygen per of water, that is 50 times higher than those typically found in ordinary freshwater lakes on Earth's surface.