A river longer than the Thames has been discovered under the Antarctic ice sheet, and scientists say it could accelerate ice loss as the climate warms.
The 286 miles (460 km) waterway was first documented by researchers from Imperial College London and other international organisations.
By comparison, the River Thames, which flows through London, is 215 miles (346 km) long.
The newly discovered river collects water from an area equal to the territory of Germany and France combined, and greatly influences the flow and melting of ice on the continent.
Scientists fear the river will increase ice loss from the base of the plate if climate change exacerbates surface melt.
Lead researcher Dr Christine Doe of the University of Waterloo said: “We can significantly underestimate the rate at which the system is melting without taking into account the impact of these river systems. We know from satellite measurements which regions of Antarctica are losing ice, and by how much, but we don’t. The reason is necessary. This finding may be the missing link in our models.”
Water under the planet’s ice sheets, which are found in Greenland around the North Pole and in Antarctica around the North Pole, can appear in two main ways: through the melting of surface ice and water flowing through deep cracks called mulleins. The second is melting at the base, caused by the Earth’s natural heat and friction as ice moves across the Earth.
In Greenland, during the warm summer, a huge amount of surface meltwater is formed, which flows through the pier, forming streams and lakes.
But in Antarctica, the temperature is not so great that it can withstand the melt water and form a mullein.
As a result, there would be relatively little water at the base of the Antarctic ice sheets.
However, thanks to a combination of airborne radar imagery and hydrological models, the researchers found a huge river system hidden under the ice sheet.
It is located in a remote and poorly explored region, which includes the ice of both East and West Antarctica and reaches the Weddell Sea.
It appears in the sea under a floating ice shelf – a glacier that extends from land and is buoyant enough to float in ocean waters.
The existence of such an extensive river system indicates the presence of a large amount of water only as a result of the melting of the base of the Antarctic ice sheet.
In addition, when river water drains into the sea below the ice shelf, it heats the water and causes it to melt from below.
In a study published in the journal Nature Geoscience, the researchers say the fact that it hasn’t been discovered for so long shows how little we know about the continent.
The river system can influence how climate change affects the region and will need to be taken into account in future models and projections.
Source: Daily Mail