"One
might assume that the Earth's landscape has been fully explored and
mapped," said Jonathan Bamber, Professor of Physical Geography at the
University of Bristol in the UK, and lead author of the study published
in today's issue of Science . "Our research shows that there is still much to discover."
The submarine canyon has the characteristics of a winding river channel and reaches at least 460 miles (750 km) long, so it has more length than the Grand Canyon. In some places is as deep as 2,600 feet (800 meters). This immense trench above is believed to be the layer of ice that has covered Greenland during the last million years.
The scientists used thousands of airborne radar data collected by NASA and researchers from the UK and Germany for decades to reconstruct the landscape under the ice sheet of Greenland.
Much of these data were collected between 2009 and 2012 by NASA's Operation IceBridge, scientific campaign eaérea studying polar ice. One of the IceBridge science instruments, the Multichannel Coherent Radar Depth Sounder, can see through large ice to measure its thickness and shape of the bedrock below.
In his analysis of the radar data, the team found a rock canyon stretching almost continuously from the center of the island and ends below the Petermann glacier fjord in northern Greenland.
At certain frequencies, radio waves can travel through the ice and bounce off the bottom of the rock-bottom. The number of times that the radio waves are launched and recovered helped researchers determine the depth of the canyon. The longer it takes, the deeper the bedrock feature.
There are two things that helped make this discovery," said Michael Studinger, IceBridge project scientist at the Goddard Space Flight Center in Greenbelt, Md. "It was the huge amount of data collected by IceBridge and the combination of work with other data sets in Greenland. Putting all existing data was to appear before our eyes this great failure ".
Researchers believe that the barrel has an important role in the transport of meltwater subglacial interior of Greenland to the edge of the ice in the ocean. The evidence suggests that the presence of the ice until 4 million years ago, water flowed into the barrel of the interior to the coast and is a major river system.
"It is quite remarkable that in the XXI century discover a channel the size of the Grand Canyon below the Greenland ice sheet," said Studinger. "This shows how little we still know about the bedrock beneath large continental ice sheets.
The campaign IceBridge Greenland again in March 2014 and will continue data collection of land and sea ice in the Arctic, using a range of instruments including ice-penetrating radar.
The submarine canyon has the characteristics of a winding river channel and reaches at least 460 miles (750 km) long, so it has more length than the Grand Canyon. In some places is as deep as 2,600 feet (800 meters). This immense trench above is believed to be the layer of ice that has covered Greenland during the last million years.
The scientists used thousands of airborne radar data collected by NASA and researchers from the UK and Germany for decades to reconstruct the landscape under the ice sheet of Greenland.
Much of these data were collected between 2009 and 2012 by NASA's Operation IceBridge, scientific campaign eaérea studying polar ice. One of the IceBridge science instruments, the Multichannel Coherent Radar Depth Sounder, can see through large ice to measure its thickness and shape of the bedrock below.
In his analysis of the radar data, the team found a rock canyon stretching almost continuously from the center of the island and ends below the Petermann glacier fjord in northern Greenland.
At certain frequencies, radio waves can travel through the ice and bounce off the bottom of the rock-bottom. The number of times that the radio waves are launched and recovered helped researchers determine the depth of the canyon. The longer it takes, the deeper the bedrock feature.
There are two things that helped make this discovery," said Michael Studinger, IceBridge project scientist at the Goddard Space Flight Center in Greenbelt, Md. "It was the huge amount of data collected by IceBridge and the combination of work with other data sets in Greenland. Putting all existing data was to appear before our eyes this great failure ".
Researchers believe that the barrel has an important role in the transport of meltwater subglacial interior of Greenland to the edge of the ice in the ocean. The evidence suggests that the presence of the ice until 4 million years ago, water flowed into the barrel of the interior to the coast and is a major river system.
"It is quite remarkable that in the XXI century discover a channel the size of the Grand Canyon below the Greenland ice sheet," said Studinger. "This shows how little we still know about the bedrock beneath large continental ice sheets.
The campaign IceBridge Greenland again in March 2014 and will continue data collection of land and sea ice in the Arctic, using a range of instruments including ice-penetrating radar.
0 comments:
Post a Comment