Lake Mercer is among about 400 subglacial lakes of liquid water that have actually been recognized throughout Antarctica, at the border of the ice and underlying rocks.

Lake Mercer clears by underground rivers into the area of the Ross Ice Rack in West Antarctica.

The biggest is Lake Vostock, in East Antarctica, which lies listed below more than 13,100 feet (4,000 m) of ice and has to do with 3,280 feet (1,000 m) deep.