Scientists with the European Space Agency's PolarGAP project have mapped for the first time three giant canyons and mountain ranges under the ice in West Antarctica.
The canyons' deep troughs are extending for hundreds of miles, winding in and out through tall mountains. The topography was invisible among the thick ice surface and was only discovered through ice-penetrating radar used by the scientists.
The team surmised that in the past, these canyons helped guide the stream of ice from the center of Antarctica in the direction of the coast.
In the event that climate change radically melts the ice sheets in the future, the canyons have direct control on how fast the ice could flow between the East and West Antarctic ice sheets and subsequently from the center of the continent to the seas. The amount of ice melted would thereby raise sea levels across the world.
The Giant Canyons
The largest canyon discovered was called the Foundation Trough and measures more than 200 miles long and over 21 miles wide. In context, its span is comparable to the distance from London to Manchester. The trough's width could be more than one and a half times the extent of New York's Manhattan Island.
The other canyon was called the Patuxent Trough which measures more than 186 miles long and more than 9 miles wide.
The third canyon was the Offset Rift Basin which measures 93 miles long and over 18 miles wide.
At present condition, these canyons are preventing the ice coming from East Antarctica to stream down through West Antarctica. If the ice sheet thaws, however, the topographically controlled corridors could facilitate an enhanced flow of ice further inland, explained Dr. Kate Winter, lead author of the study published in the journal Geophysical Research Letters.
The West Antarctic ice divide will then make a major shift, creating channels for gushing melted ice to stream down from the center of Antarctica to its boundaries, straight into the oceans worldwide.
Winter, who is also a vice-chancellor's research fellow in Northumbria University's Department of Geography and Environmental Sciences, reiterated that this chain effect will result in a remarkable increase in sea levels across the world.
The PolarGAP Project
ESA has mounted two Earth-observing satellite missions to help scientists map the Earth's global gravity field. These satellites are also monitoring how ice fields are responding to climate change.
These satellites, however, did not cross the Poles and that resulted to a data gap at the South Pole. This gap is now the focus of the PolarGAP project and the discovery of the three vast canyons under Antarctica is the first output of the team working for the mission.
Now that the PolarGAP project is analyzing the South Pole, the team is ultimately hoping that they could create the first accurate and complete representation or model of the Earth's global gravity field.