The West Antarctic crank sheet’simperiled glaciersget all the attention , but there ’s aneven large pile of frozen wateracross the continent that scientists are starting to concern about . The East Antarctic glass sheet has long been considered very frozen and very static — but a new analysis of some of its largest glacier suggests this video might be wrong .
Astudypublished Wednesday in the daybook Nature takes a inscrutable prima donna into the history of East Antarctica ’s Sabrina Coast , which empties glacier flux off the huge frosting sheet blanket the Aurora Basin . By constructing maps of the sediment layer surround the coastline , the research worker find out that its glaciers have only been unchanging for the past six million geezerhood or so .
Before that — for the bulk of the full stop since Antarctica ’s continent - wide ice sheets emerged some 34 million years ago — the glacier protecting the Sabrina Coast went through nearly a dozen hertz of progress and retirement , as the climate cool down off and warmed up .
According to co - lead study author Sean Gulick of the University of Texas at Austin , that upend the prevailing motion-picture show of East Antarctica , as a landscape that ’s been lock in a deep freeze for tens of gazillion of days . And it raises worrying opening about the future of the Aurora Basin ice mainsheet , which hold enough H2O to kindle global sea levels by up to 15 ft .
“ It ’s kind of a very different characterization than East Antarctica today , ” Gulick tell Earther , adding that this Modern abstruse - time picture , of glacier growing and shrinkage , is more like what we see in Alaska today than what we ’d expect for the frozen continent at the bottom of the existence .
The analysis was groundbreaking in more ways than one . The research worker were literally the first to bring down this section of the East Antarctic coastline , back in the austral summer of 2014 . To get there , the scientists had to take a special icebreaking inquiry vas , theR / V N. B. Palmer , through fringing ocean ice into chartless pee near where ice shelves are tether to land . With no baythmetric map of the seafloor , they had to be measured not to run aground .
Once they made it to relatively receptive waters near the coastline , the investigator used seismal manifestation profiling — basically , they shot levelheaded waving into the seafloor and listened to the reflections — to construct a map of sediment layers representing the ontogenesis and retirement of glacier over sentence . They also collected sediment kernel and examined microfossils and pollen grains to figure out more or less when key polar advance and retreat events occurred .
In addition to identifying 11 full stop of ice - barren consideration — span the late Eocene 40 million years ago to the later Miocene 6 million years ago — the resultant seafloor deposit profile unwrap encompassing “ burrow valley , ” features that descriptor when meltwater percolate through an ice sheet to bedrock and literally carves out a vale . In this case , those tunnel are kilometers wide and hundreds of meters bass , suggest at a time when vast river of urine gushed through the crank sheet of paper to the sea .
“ This is a well lie with phenomenon from northerly ice sheets , ” Gulick said . “ We just have n’t look that in Antarctica because it ’s a bury record . ”
Thomas Wagner , director of NASA ’s polar skill program who was not involved with the research , called the work “ keen work in a poorly consider part of the public . ”
“ The evidence they set up is rare — like fossil dinosaur rare , ” he told Earther , noting that we have very slight geologic evidence about how old East Antarctic ice behaves . “ It gives us new ideas for how to do sea level rise projection and offer some ideas for us to test — for example what form of atmospheric stipulation would cause that much melting in that part of Antarctica ? ”
Gulick noted that many of the methamphetamine - free period of time register in these sediments occurred during times when atmospheric CO2 levels were uncomfortably close to where we ’re at today . “ These are the form of [ CO2 ] numeral we ’re have a bun in the oven to reach ” by the conclusion of the century , he said .
And if the end of the century feels far aside , bear in mind that the region ’s largest glacier — Totten Glacier , nicknamed “ slumber giant ” of East Antarctica — may already be feeling the heat of ball-shaped warming . quick sea water is do Totten to thin faster than any other East Antarctic electric outlet glacier , and arecent study foundthat fortify wind could get seawater to undersell the ice shelf even faster in the future .
Totten Glacier alone hold in enough piss to put up world-wide sea grade by 11 feet .
Part of the problem with Totten — and the Aurora Basin ice sheet in general — is that most of its basics lies below ocean tier . If the ground part of the ice sheet pull aside from the underlying bedrock , theice can in theory enter a United States Department of State of sudden , dramatic retirement .
“ you may envision if you start retreating from the grounded part of the Methedrine sheet , [ the ice-skating rink ] can retreat quite a ways , ” until you arrive at high priming further inland , Gulick said . “ There ’s not a lot of cause it ’s going to stop . ”
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