Tech

August 31, 2013

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 long, making it longer than the Grand Canyon. In some places, it is as deep as 2,600 feet, 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.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines August 28, 2014

News: After F-15 jet crash in Virginia, rescue helicopters search for pilot - Helicopters are searching for an Air National Guard pilot after his F-15 jet crashed in the mountains of Virginia this morning, military officials said.   Business: U.S. Air Force 3DELRR contract expected soon - The U.S. Air Force could award the contract for its...
 
 

News Briefs August 28, 2014

Russian directing new offensive in Ukraine The Obama administration believes Russia is leading a new military counteroffensive in Ukraine. U.S. State Department spokeswoman Jen Psaki says Russia has sent additional columns of tanks and armored vehicles into its neighbor’s territory. She says the incursions suggest a ìRussian-directed counteroffensive is likely underway in the contested e...
 
 
LM-C5

Double Deuce

A U.S. Air Force crew ferried the 22nd C-5M Super Galaxy from the Lockheed Martin facilities in Marietta, Ga., Aug. 25. Aircraft 86-0011 was ferried by a crew led by Maj. Gen. Dwyer L. Dennis, Director, Global Reach Programs, O...
 

 
Northrop Grumman photograph

First ever RQ-4 Global Hawk hits 100th flight on NASA mission

Northrop Grumman photograph A historical look at the first Global Hawk (AV1) during its maiden flight over Edwards Air Force Base, Calif., on Feb. 28, 1998. AV1 has made history again with its 100th flight in support of NASA en...
 
 

Northrop Grumman’s CIRCM system completes U.S. Army flight testing

Northrop Grumman’s Common Infrared Countermeasures system recently completed another round of U.S. Army testing by demonstrating its capabilities on a UH-60M Black Hawk helicopter. The flight test was conducted at Redstone Arsenal in Huntsville, Ala., by the Redstone Test Center. The Northrop Grumman CIRCM system was subjected to rigorous conditions over a six-week period, after...
 
 
NASA photograph by David Olive

NASA completes successful battery of tests on composite cryotank

https://www.youtube.com/embed/qkGI6JeNY0E?enablejsapi=1&rel=0 NASA photograph by David Olive One of the largest composite cryotanks ever built recently completed a battery of tests at NASA’s Marshall Space Flight Cen...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>