Although it looks ancient and unchanging, the ice sheet in Antarctica is a surprisingly active place. Deep beneath the sheet’s surface, there are waterways, channels and pipes that connect various subglacial “lakes”. These channels can cause these lakes to drain away into the ocean, or transfer water from one to the other.
Now data gathered by NASA satellites shows these fast-moving ice streams in action. The satellites – Terra, Aqua and ICESat – are able to measure changes in ice elevation as small as 1 metre (3 feet). As a subglacial lake drains, the elevation of ice above it falls accordingly.
These subglacial rivers seem to play an important role in the movement, growth and decay of the ice sheets above them. They could contribute a surprisingly large amount of the fresh water dumped into the nearby coastal oceans.
Original Source: NASA News Release