Giant "blisters" containing water that rapidly expand and contract have been mapped beneath the Antarctic ice sheet. Fed by a complex network of rivers, the subglacial reservoirs force the overlying ice to rise and fall. By tracking these changes with NASA's Ice Cloud and land Elevation Satellite (ICESat) scientists were able to map the extent of the subglacial plumbing.

Climate response

Nearly 150 subglacial lakes have been identified beneath the vast Antarctic ice sheet.

The new ones were found under the fast-flowing Whillans and Mercer Ice Streams that carry ice from the interior of the West Antarctic Ice Sheet to the floating Ross Ice Shelf.

Ebb and flow

Using elevation data from NASA's ICESat, cross-checked with other NASA satellites, the team was able to map the rise and fall of the overlying ice, and hence areas where water pooled or flowed away.

Launched in 2003, ICESat can measure changes in elevation as small as 1.5cm (0.6ins) from its orbit 645km (400 miles) above the Earth. The study revealed a complex network of ponds and rivers, the largest of which occurred under the Whillans ice stream and covered an area of 500 sq km (190 sq miles). It also showed that water was constantly moving between different reservoirs.

https://www.bibliotecapleyades.lege.net/antarctica/antartica04.htm