Clarksville, TN Online: News, Opinion, Arts & Entertainment.


Topic: West Antarctica

NASA ICESAT Satellites use laser to map Greenland, Antarctica Ice Loss over 16 years

 

NASA - National Aeronautics and Space AdministrationGreenbelt, MD – Using the most advanced Earth-observing laser instrument NASA has ever flown in space, scientists have made precise, detailed measurements of how the elevation of the Greenland and Antarctic ice sheets have changed over 16 years.

The results provide insights into how the polar ice sheets are changing, demonstrating definitively that small gains of ice in East Antarctica are dwarfed by massive losses in West Antarctica.

The Kangerdlugssup (pictured) and Jakobshavn glaciers in Greenland have lost roughly 14 to 20 feet (4 to 6 meters) of elevation per year over the past 16 years. (NASA/Jim Yungel)

The Kangerdlugssup (pictured) and Jakobshavn glaciers in Greenland have lost roughly 14 to 20 feet (4 to 6 meters) of elevation per year over the past 16 years. (NASA/Jim Yungel)

«Read the rest of this article»

Sections: Technology | No Comments
 

NASA study shows Denman Glacier vulnerable to Seawater Intrusion

 

NASA - National Aeronautics and Space AdministrationPasadena, CA – According to a new study by scientists at NASA’s Jet Propulsion Laboratory and the University of California, Irvine, the Denman Glacier in East Antarctica retreated 3.4 miles (5.4 kilometers) from 1996 to 2018. Their analysis of Denman – a single glacier that holds as much ice as half of West Antarctica – also shows that the shape of the ground beneath the ice sheet makes it especially susceptible to climate-driven retreat.

Until recently, researchers believed East Antarctica was more stable than West Antarctica because it wasn’t losing as much ice compared to the glacial melt observed in the western part of the continent.

This photograph shows ripples in the surface of Denman Glacier in East Antarctica that throw shadows against the ice. The glacier is melting at a faster rate now than it was from 2003 to 2008. (NASA)

This photograph shows ripples in the surface of Denman Glacier in East Antarctica that throw shadows against the ice. The glacier is melting at a faster rate now than it was from 2003 to 2008. (NASA)

«Read the rest of this article»

Sections: Technology | No Comments
 

NASA Study finds evidence of Geothermal Heat Source under West Antarctica

 

Written by Carol Rasmussen
NASA’s Earth Science News Team

NASA - National Aeronautics and Space AdministrationWashington, D.C. – A new NASA study adds evidence that a geothermal heat source called a mantle plume lies deep below Antarctica’s Marie Byrd Land, explaining some of the melting that creates lakes and rivers under the ice sheet.

Although the heat source isn’t a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today.

The stability of an ice sheet is closely related to how much water lubricates it from below, allowing glaciers to slide more easily.

Illustration of flowing water under the Antarctic ice sheet. Blue dots indicate lakes, lines show rivers. Marie Byrd Land is part of the bulging "elbow" leading to the Antarctic Peninsula, left center. (NSF/Zina Deretsky)

Illustration of flowing water under the Antarctic ice sheet. Blue dots indicate lakes, lines show rivers. Marie Byrd Land is part of the bulging “elbow” leading to the Antarctic Peninsula, left center. (NSF/Zina Deretsky)

«Read the rest of this article»

Sections: Technology | No Comments
 


NASA Study reveals Antarctic Glacier’s Ice Loss May Not Progress as Quickly as Thought

 

Written by Carol Rasmussen
NASA’s Earth Science News Team

NASA - National Aeronautics and Space AdministrationWashington, D.C. – The melt rate of West Antarctica’s Thwaites Glacier is an important concern, because this glacier alone is currently responsible for about 1 percent of global sea level rise. A new NASA study finds that Thwaites’ ice loss will continue, but not quite as rapidly as previous studies have estimated.

The new study, published in the journal Geophysical Research Letters, finds that numerical models used in previous studies have overestimated how rapidly ocean water is able to melt the glacier from below, leading them to overestimate the glacier’s total ice loss over the next 50 years by about 7 percent.

Thwaites Glacier. (NASA/James Yungel)

Thwaites Glacier. (NASA/James Yungel)

«Read the rest of this article»

Sections: Technology | No Comments
 

NASA reports new study reveals Intense Melting beneath West Antarctic Glaciers

 

Written by Alan Buis
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – Two new studies by researchers at NASA and the University of California, Irvine (UCI), detect the fastest ongoing rates of glacier retreat ever observed in West Antarctica and offer an unprecedented direct view of intense ice melting from the floating undersides of glaciers.

The results highlight how the interaction between ocean conditions and the bedrock beneath a glacier can influence the glacier’s evolution, with implications for understanding future ice loss from Antarctica and global sea level rise.

A view from Operation IceBridge's aircraft of Crosson Ice Shelf, foreground. Mt. Murphy is in the background. (NASA/OIB/Michael Studinger)

A view from Operation IceBridge’s aircraft of Crosson Ice Shelf, foreground. Mt. Murphy is in the background. (NASA/OIB/Michael Studinger)

«Read the rest of this article»

Sections: Technology | No Comments
 

NASA uses satellite data to solve questions about Earth’s rotational wobbles

 

Written by Alan Buis
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – Using satellite data on how water moves around Earth, NASA scientists have solved two mysteries about wobbles in the planet’s rotation — one new and one more than a century old. The research may help improve our knowledge of past and future climate.

Although a desktop globe always spins smoothly around the axis running through its north and south poles, a real planet wobbles. Earth’s spin axis drifts slowly around the poles; the farthest away it has wobbled since observations began is 37 feet (12 meters).

Earth does not always spin on an axis running through its poles. Instead, it wobbles irregularly over time, drifting toward North America throughout most of the 20th Century (green arrow). That direction has changed drastically due to changes in water mass on Earth. (NASA/JPL-Caltech)

Earth does not always spin on an axis running through its poles. Instead, it wobbles irregularly over time, drifting toward North America throughout most of the 20th Century (green arrow). That direction has changed drastically due to changes in water mass on Earth. (NASA/JPL-Caltech)

«Read the rest of this article»

Sections: Technology | No Comments
 

NASA Scientists find Hidden Canyons under Greenland that increases sea level rise estimates for the future

 

Written by Alan Buis
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – Scientists at NASA and the University of California, Irvine (UCI), have found that canyons under Greenland’s ocean-feeding glaciers are deeper and longer than previously thought, increasing the amount of Greenland’s estimated contribution to future sea level rise.

“The glaciers of Greenland are likely to retreat faster and farther inland than anticipated, and for much longer, according to this very different topography we have discovered,” said Mathieu Morlighem, a UCI associate project scientist who is lead author of the new research paper. The results were published in the journal Nature Geoscience.

A glacier in the Sukkertoppen ice cap, southwest Greenland, flows down a rocky canyon like those mapped in this study. (NASA)

A glacier in the Sukkertoppen ice cap, southwest Greenland, flows down a rocky canyon like those mapped in this study. (NASA)

«Read the rest of this article»

Sections: Technology | No Comments
 


West Antarctic Ice Sheet unstoppable loss not unexpected by NASA Scientists

 

Written by Patrick Lynch
NASA’s Earth Science News Team

NASA - National Aeronautics and Space AdministrationPasadena, CA – The new finding that the eventual loss of a major section of West Antarctica’s ice sheet “appears unstoppable” was not completely unexpected by scientists who study this area.

The study, led by glaciologist Eric Rignot at NASA’s Jet Propulsion Laboratory, Pasadena, California, and the University of California, Irvine, follows decades of research and theory suggesting the West Antarctic Ice Sheet is inherently vulnerable to change.

Although the Amundsen Sea region is only a fraction of the whole West Antarctic Ice Sheet, the region contains enough ice to raise global sea levels by 4 feet (1.2 meters). (NASA/GSFC/SVS)

Although the Amundsen Sea region is only a fraction of the whole West Antarctic Ice Sheet, the region contains enough ice to raise global sea levels by 4 feet (1.2 meters). (NASA/GSFC/SVS)

«Read the rest of this article»

Sections: Technology | No Comments
 

NASA study reveals West Antarctic Glacier melting appears to be irreversible

 

Written by Alan Buis
NASA’s Jet Propulsion Laboratory

NASA - National Aeronautics and Space AdministrationPasadena, CA – A new study by researchers at NASA and the University of California, Irvine, finds a rapidly melting section of the West Antarctic Ice Sheet appears to be in an irreversible state of decline, with nothing to stop the glaciers in this area from melting into the sea.

The study presents multiple lines of evidence, incorporating 40 years of observations that indicate the glaciers in the Amundsen Sea sector of West Antarctica “have passed the point of no return,” according to glaciologist and lead author Eric Rignot, of UC Irvine and NASA’s Jet Propulsion Laboratory in Pasadena, California.

Thwaites Glacier. (NASA)

Thwaites Glacier. (NASA)

«Read the rest of this article»

Sections: Technology | No Comments
 



  • Visit Us On FacebookVisit Us On TwitterVisit Us On PinterestVisit Us On YoutubeCheck Our FeedVisit Us On Instagram
  • Personal Controls

    Now playing at the Movies