NASA data reveals mega-canyon under Greenland Ice Sheet
Data from a NASA airborne science mission reveals evidence of a large and previously unknown canyon hidden under a mile of Greenland ice. The canyon has the characteristics of a winding river channel and is at least 460 miles (750 kilometers) long, making it longer than the Grand Canyon. In some places, it is as deep as 2,600 feet (800 meters), on scale with segments of the Grand Canyon. This immense feature is thought to predate the ice sheet that has covered Greenland for the last few million years.
"One might assume that the landscape of the Earth has been fully explored and mapped," said Jonathan Bamber, professor of physical geography at the University of Bristol in the United Kingdom, and lead author of the study. "Our research shows there's still a lot left to discover."
Bamber's team published its findings Thursday in the journal Science.
The scientists used thousands of miles of airborne radar data, collected by NASA and researchers from the United Kingdom and Germany over several decades, to piece together the landscape lying beneath the Greenland ice sheet.
A large portion of this data was collected from 2009 through 2012 by NASA's Operation IceBridge, an airborne science campaign that studies polar ice. One of IceBridge's scientific instruments, the Multichannel Coherent Radar Depth Sounder, can see through vast layers of ice to measure its thickness and the shape of bedrock below.
In their analysis of the radar data, the team discovered a continuous bedrock canyon that extends from almost the center of the island and ends beneath the Petermann Glacier fjord in northern Greenland.
At certain frequencies, radio waves can travel through the ice and bounce off the bedrock underneath. The amount of times the radio waves took to bounce back helped researchers determine the depth of the canyon. The longer it took, the deeper the bedrock feature.
"Two things helped lead to this discovery," said Michael Studinger, IceBridge project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "It was the enormous amount of data collected by IceBridge and the work of combining it with other datasets into a Greenland-wide compilation of all existing data that makes this feature appear in front of our eyes."
The researchers believe the canyon plays an important role in transporting sub-glacial meltwater from the interior of Greenland to the edge of the ice sheet into the ocean. Evidence suggests that before the presence of the ice sheet, as much as 4 million years ago, water flowed in the canyon from the interior to the coast and was a major river system.
"It is quite remarkable that a channel the size of the Grand Canyon is discovered in the 21st century below the Greenland ice sheet," said Studinger. "It shows how little we still know about the bedrock below large continental ice sheets."
The IceBridge campaign will return to Greenland in March 2014 to continue collecting data on land and sea ice in the Arctic using a suite of instruments that includes ice-penetrating radar.
- Massive canyon discovered buried under Greenland icefrom The Guardian - ScienceSun, 1 Sep 2013, 12:30:52 EDT
- Wow! The Most Amazing Images in Science This Weekfrom Live ScienceSat, 31 Aug 2013, 4:30:24 EDT
- Massive canyon discovered buried under Greenland icefrom The Guardian - ScienceFri, 30 Aug 2013, 11:30:17 EDT
- Revealed: A Grand Canyon Under The Greenland Ice Sheetfrom Scientific BloggingThu, 29 Aug 2013, 19:40:15 EDT
- Radar finds canyon longer than Grand Canyon hidden under Greenland icefrom UPIThu, 29 Aug 2013, 18:30:21 EDT
- Massive canyon discovered under ice sheet in Greenlandfrom CBSNews - ScienceThu, 29 Aug 2013, 18:30:14 EDT
- Mega-Canyon Discovered Beneath Greenland Ice Sheetfrom PopSciThu, 29 Aug 2013, 17:30:27 EDT
- NASA Data Reveals Mega-Canyon under Greenland Ice Sheetfrom Science BlogThu, 29 Aug 2013, 17:30:16 EDT
- Video: Mega-canyon discovered beneath Greenland's ice sheetfrom CBSNews - ScienceThu, 29 Aug 2013, 17:30:10 EDT
- Mega-Canyon Discovered Beneath Greenland Icefrom Science @ NASAThu, 29 Aug 2013, 17:00:17 EDT
- 'Grand Canyon of Greenland' discovered under ice sheetfrom MSNBC: ScienceThu, 29 Aug 2013, 16:30:54 EDT
- VIDEO: Deep canyon under Greenland icefrom BBC News: Science & NatureThu, 29 Aug 2013, 16:30:29 EDT
- Greenland's 'Grand Canyon' Revealed By Ice-Penetrating Radar | Videofrom Space.comThu, 29 Aug 2013, 16:30:20 EDT
- Greenland's 'Grand Canyon' Revealed By Ice-Penetrating Radar | Videofrom Live ScienceThu, 29 Aug 2013, 16:30:18 EDT
- Giant Canyon Discovered Under Greenland Ice Sheetfrom National GeographicThu, 29 Aug 2013, 15:00:21 EDT
- NASA data reveals mega-canyon under Greenland ice sheetfrom Science DailyThu, 29 Aug 2013, 14:31:09 EDT
- 'Grand Canyon' of Greenland Discovered Under Ice Sheetfrom Live ScienceThu, 29 Aug 2013, 14:30:39 EDT
- News in Brief: Big canyon entombed beneath Greenland's icefrom Sciencenews.orgThu, 29 Aug 2013, 14:20:07 EDT
- Mega-canyon discovered beneath Greenland ice sheetfrom PhysorgThu, 29 Aug 2013, 14:00:47 EDT
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