The Southern Continent's Hidden Landmass Revealed
The southernmost continent of Antarctica is almost entirely covered with a thick sheet of ice. The average thickness of the ice is an amazing one mile (1.6 km), and up to 3 miles thick in some places. Scientists from the British Antarctic Survey have published a new detailed map which pierces the ice to see the land mass below. They found mountain chains which rival the European Alps, and that large portions of the frozen continent actually rest on the sea bed, not on land.
The map was compiled from data collected by aerial flights, satellites, and research ships, over a span of 50 years. The imagery created is known as BEDMAP, and it reveals a magnificent landscape hidden under thousands of feet of ice.
The map can be extremely useful in predicting how future melting will occur on the continent. Current scientific research shows the majority of melting and calving occurring on the margins of the continent. The map will help show which areas would melt first.
"This is information that underpins the models we now use to work out how the ice flows across the continent," explained Hamish Pritchard from the British Antarctic Survey (BAS). "The Antarctic ice sheet is constantly supplied by falling snow, and the ice flows down to the coast where great bergs calve into the ocean or it melts. It's a big, slow-speed hydrological cycle.
"To model that process requires knowledge of some complex ice physics but also of the bed topography over which the ice is flowing - and that's BEDMAP."
Perhaps the most striking feature revealed in the map is the Gamburtsev Mountains, a range that is the size of the European Alps. The tallest peaks reach 3,000 meters (9,850 feet) above sea level with an additional 1,000 meters (3,280 feet) of ice on top!
"It's fascinating to see the Gamburtsevs in the context of the other big mountains in Antarctica," said Dr Pritchard. "They're similar in size to the likes of the Ellsworth and the Transantarctic mountains, but of course they're completely buried. It is just because the ice is so thick in the middle of the ice sheet that they're not exposed."
The BEDMAP imagery will be presented at this week's meeting of the American Geophysical Union.
Image credit: Bedmap Consortium/British Antarctic Survey