A subglacial lake is a lake that is found under a glacier, typically beneath an ice cap or ice sheet. Subglacial lakes form at the boundary between ice and the underlying bedrock, where pressure decreases the pressure melting point of ice. Over time, the overlying ice gradually melts at a rate of a few millimeters per year. Meltwater flows from regions of high to low hydraulic pressure under the ice and pools, creating a body of liquid water that can be isolated from the external environment for millions of years.
Satellite image of subglacial Lake Vostok in Antarctica. Image credit: NASA
Russian scientist Peter Kropotkin first proposed the idea of fresh water under Antarctic ice.
An artist's depiction of the subglacial lakes and rivers beneath the Antarctic Ice Sheet. Image credit: Zina Deretsky / US National Science Foundation
An illustration of ice core drilling above subglacial Lake Vostok. These drilling efforts collected re-frozen lake water that has been analyzed to understand the lake's chemistry. Image credit: Nicolle Rager-Fuller / US National Science Foundation
A lake is a naturally occurring, relatively large and fixed body of water on the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers, such as Lake Ontario. Most lakes are freshwater and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume.
Lac Gentau in the Ossau Valley of the Pyrenees, France
Lake Michigan during a storm near the Ludington Lighthouse
The crater lake of Mount Rinjani, Indonesia
Lake Kaniere is a glacial lake in the West Coast region of New Zealand.
