Subglacial lakes in Antarctica were first identified in the 1960s, some sealed beneath up to 2 1/2 miles of ice. Since then, more than 150 have been discovered. But it is thought thousands may exist. The largest is Lake Vostok, similar in size to Lake Ontario. Another is the size of Rhode Island.
Baldwin and her colleagues believe there must be a more complete investigation of how a similar catastrophic release might alter the present-day environment.
Such a massive release of fresh water from the subglacial lakes would affect the stability of the East Antarctic ice sheet, the circulation of water in the Southern Ocean, and global weather patterns, all of which could change the balance of the Earth's ecosystems, she said.
Dominic Hodgson, a geologist at the British Antarctic Survey, said formation of the Labyrinth has been attributed to subglacial meltwater since at least 1993, but the Syracuse study provided a "better estimate" of the timing of its creation.
Hodgson, who has written extensively about global warming and its impact on Antarctica, said some lake water discharges are contemporary. One such rapid discharge occurred in 1997-1998 when a one-mile-square lake emptied into two other downstream lakes under the ice sheet over a period of 16 months.
"It is very unlikely that the volume of these discharges would equal those of the Miocene (epoch), when the Labyrinth formed, because the ice sheet then was much more dynamic and temperate and therefore likely contained — and discharged — substantially greater volumes of subglacial meltwater," Hodgson said.
The British scientist said that present day global warming has not had any measured effects on the volume or movement of subglacial meltwater beneath the Antarctic ice sheet "so it is premature to predict a new era of flooding as a result of global warming."
