region:east antarctica

This Part Of Antarctica Was Not Supposed To Be Shrinking | Gizmodo Australia
▻https://www.gizmodo.com.au/2019/01/this-part-of-antarctica-was-not-supposed-to-be-shrinking

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That suggests it’s far from the end of the story for this very big, very remote, and very poorly studied part of the world. New datasets expected to come online from satellite missions like GRACE-Follow On, which uses gravity data to track Antarctica’s weight loss, and ICESat-2, which measures the height of icy surfaces, should help researchers refine the picture even further.

But this isn’t the first time a study has punched a hole in East Antarctica’s icy fortitude. A study published last summer found that two critical East Antarctic outlet glaciers, Totten and Moscow University #glacier, are shedding some 18 billion tons of ice a year. More recently, NASA researchers estimated that four #glaciers west of Totten have lost nine feet of surface height since 2008.

One thing’s for certain: If East Antarctica is losing weight, and if that trend accelerates, the future of Earth’s coastlines could start to look a lot dimmer.

#antarctique #eau #climat

East Antarctic icesheet unsettles science
▻http://us6.campaign-archive2.com/?u=6e13c74c17ec527c4be72d64f&id=b145258428&e=08052803c8

East Antarctic icesheet unsettles science

Scientists now believe that the East Antarctic ice sheet could become unstable, a discovery with potentially serious global implications.

By Tim Radford

LONDON, 17 December, 2016 – East Antarctica, the supposedly stable sheet of ice that makes up the greater part of the Southern Continent, may not be so stable after all. Scientists from the Netherlands have identified a mechanism that can trigger melting deep in the huge ice shelf.

And an international team of researchers has found that the planet’s single greatest body of ice is not just vulnerable to disintegration, but has played a dynamic role in natural climate change for at least 8,000 years.

The continent carries most of the world’s fresh water in the form of ice: if it all melted, sea levels would rise by 60 metres or more. But the process would take millennia and anyway, the latest research does not suggest that the East Antarctica ice sheet is unstable: just that, like the fast-warming West Antarctica region, it could become unstable.

#climat #antarctique #arctique #it_has_begun

Speedy Antarctic drills start hunt for Earth’s oldest ice
▻http://www.nature.com/news/speedy-antarctic-drills-start-hunt-for-earth-s-oldest-ice-1.21061

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In December, the first drill designed to search for a scientifically useful sample of ice that is at least 1.5 million years old will begin its work. It is part of a broader effort to locate the best place to extract a core containing Earth’s oldest ice, which would help to reveal how climate has shaped the planet’s past and how to predict future fluctuations.

[...] More than a decade ago, the European Project for Ice Coring in Antarctica (EPICA) drilled the oldest existing core, which contains 800,000-year-old ice, from an ice dome in East Antarctica known as Dome C. The core reaches only as far back as the latter part of the Pleistocene epoch, when Earth began cycling between warm and cold periods every 100,000 years. Before 1 million years ago, the cycle occurred every 40,000 years (...), so scientists want an ice core that is twice as old as EPICA to better understand this transition.

Digging such a core would cost about US$50 million and take several years, so researchers want to be sure that the location is optimal — with ice that is sufficiently deep but not melted at the bottom by geothermal activity. “It’s absolutely crucial to thoroughly investigate all options,” says Eisen. Enter a new breed of drill, designed to do fast, cheap reconnaissance instead of extracting a single, intact ice core, as previous deep drills have done.

#climat #Antarctique

Dazzling blue lakes are forming in Antarctica — and they’ve got scientists worried

In a new study, scientists who study the largest ice mass on Earth — East Antarctica — have found that it is showing a surprising feature reminiscent of the fastest melting one: Greenland.

▻https://www.washingtonpost.com/news/energy-environment/wp/2016/08/17/these-stunning-blue-lakes-just-gave-us-a-new-reason-to-worry-about-a
#Antarctique #climat #changement_climatique #fonte_des_glaces

NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses | NASA
▻https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses

https://www.nasa.gov/sites/default/files/thumbnails/image/figure-dmdt-map.png#.jpg

A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed  to 82 billion tons of ice per year between 2003 and 2008.

“We’re essentially in agreement with other studies that show an increase in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island region of West Antarctica,” said Jay Zwally, a glaciologist with NASA Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study, which was published on Oct. 30 in the Journal of Glaciology. “Our main disagreement is for East Antarctica and the interior of West Antarctica – there, we see an ice gain that exceeds the losses in the other areas.” Zwally added that his team “measured small height changes over large areas, as well as the large changes observed over smaller areas.”

Scientists calculate how much the ice sheet is growing or shrinking from the changes in surface height that are measured by the satellite altimeters. In locations where the amount of new snowfall accumulating on an ice sheet is not equal to the ice flow downward and outward to the ocean, the surface height changes and the ice-sheet mass grows or shrinks.

But it might only take a few decades for Antarctica’s growth to reverse, according to Zwally. “If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they’ve been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years — I don’t think there will be enough snowfall increase to offset these losses.”