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 May 29, 2015

News: U.S. Army chief opens door to embedding U.S. troops with Iraqi forces - After the fall of Ramadi, the Iraqi Security Forces need military and political leadership, Gen. Raymond Odierno says.   Business: No acquisition strategy yet for LCS frigates - Details of the new Littoral Combat Ship frigate program’s acquisition strategy are still being reviewed,...
 
 

News Briefs May 29, 2015

Finnish navy: Underwater intruder possible foreign submarine Finnish military officials say that an underwater object the navy chased last month in territorial waters and dropped several depth charges could have been a foreign submarine. A navy investigation released May 28 says that technical analysis did not provide sufficient proof of the presence of a submarine...
 
 
Lockheed Martin photograph by Chad Bellay

F-16 test pilots hit the ‘road’ to help train USAFE pilots

Air Force photograph by Airman 1st Class Kyla Gifford Three F-16s assigned to Spangdahlem Air Base, Germany, on a refueling mission last year. Two F-16 test pilots from the 416th Flight Test Squadron recently returned from a &#...
 

 
Navy photograph

Its reign in the fleet over, naval Sea King helicopter now rests at Pax Museum

Navy photograph At more than 54 feet in length with a 62-foot rotor diameter, the mighty SH-3A Sea King helicopter sits in its final spot at the Patuxent River Naval Air Museum. Designed as an anti-submarine warfare helicopter,...
 
 
boeing-korea

New Boeing Avionics Facility to enhance ROKAF readiness, affordability

Boeing formally opened a new avionics maintenance and repair center in the Yeongcheon Industry District of Daegu-Gyeongbuk Free Economic Zone May 28. The 10,000 square-foot facility will test and repair aircraft electrical syst...
 
 
Navy photograph by John F. Williams

ONR testing high-speed planing hulls

Navy photograph by John F. Williams A ship hull model attached to a high-speed sled moves through waves at the David Taylor Model Basin at Naval Surface Warfare Center, Carderock, during Office of Naval Research -sponsored rese...
 




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>