Using the unmanned submarine Ran, researchers mapped the underside of West Antarctica’s Dotson Ice Shelf, uncovering complex ice formations and significant melt areas driven by underwater currents, crucial for enhancing sea level rise predictions.
An international research team from the University of Gothenburg deployed the unmanned submarine ‘Ran’ beneath the thick ice of Antarctica. They received the first-ever detailed maps of the underside of a glacier, providing valuable insights into potential future sea level rise.
The autonomous underwater vehicle, Ran, was programmed to dive into the cavity of Dotson ice shelf in West Antarctica and scan the ice above it with an advanced sonar system. For 27 days, the submarine traveled a total of over 1.000 kilometers back and forth under the glacier, reaching 17 kilometers into the cavity. An ice shelf is a mass of glacial ice, fed from land by tributary glaciers, that floats in the sea above an ice shelf cavity.
“Like seeing the back of the moon”
“We have previously used satellite data and ice cores to observe how glaciers change over time. By navigating the submersible into the cavity, we were able to get high-resolution maps of the ice underside. It’s a bit like seeing the back of the moon,” says lead author Anna Wåhlin, Professor of Oceanography at the University of Gothenburg.
In a new scientific paper in Science Advances, the researchers report on the findings of this unique survey. Some things are as expected. The glacier melts faster where strong underwater currents erode its base. Using the submersible, scientists were able to measure the currents below the glacier for the first time and prove why the western part of the Dotson Ice Shelf melts so fast. They also see evidence of very high melt at vertical fractures that extend through the glacier.
But the researchers also saw new patterns on the glacier base that raise questions. The surface is not smooth, but there is a peak and valley icescape with plateaus and formations resembling sand dunes. The researchers hypothesize that these may have been formed by flowing water under the influence of Earth’s rotation.
Complex areas
Karen Alley, a glaciologist from the University of Manitoba and co-author of this multidisciplinary study, comments on the findings:
“The maps that Ran produced represent a huge progress in our understanding of Antarctica’s ice shelves. We’ve had hints of how complex ice-shelf bases are but Ran uncovered a more extensive and complete picture than ever before. The imagery from the base of Dotson Ice shelf helps us interpret and calibrate what we see from the satellites,” says Karen Alley.
Scientists now realize there is a wealth of processes left to discover in future research missions under the glaciers.
“The mapping has given us a lot of new data that we need to look at more closely. It is clear that many previous assumptions about the melting of glacier undersides are falling short. Current models cannot explain the complex patterns we see. But with this method, we have a better chance of finding the answers,” says Anna Wåhlin.
Better models
Dotson Ice Shelf is part of the West Antarctica ice sheet, considered to have a potentially large impact on future sea level rise due to its size and location.
“Better models are needed to predict how fast the ice shelves will melt in the future. It is exciting when oceanographers and glaciologists work together, combining remote sensing with oceanographic field data. This is needed to understand the glaciological changes taking place – the driving force is in the ocean,” says Anna Wåhlin.
A daunting experience
Anna Wåhlin continues: “There are not many uncharted areas left on Earth. To see Ran disappear into the dark, unknown depths below the ice, executing her tasks for over 24 hours without communication, is of course daunting. Experience from over 40 missions below ice gave us confidence but in the end, the challenging environment beat us.”
The fieldwork for this study was conducted in 2022. In January 2024, the group returned with Ran to Dotson Ice Shelf to repeat the surveys, hoping to document changes.
They were only able to repeat one dive below Dotson’s ice shelf before Ran disappeared without a trace.
“Although we got valuable data back, we did not get all we had hoped for. These scientific advances were made possible thanks to the unique submersible that Ran was. This research is needed to understand the future of Antarctica’s ice sheet, and we hope to be able to replace Ran and continue this important work,” says Anna Wåhlin.
For more on the disappearance of Ran, see The Mysterious Disappearance of an Underwater Explorer in Antarctica.
Reference: “Swirls and scoops: Ice base melt revealed by multibeam imagery of an Antarctic ice shelf” by Anna Wåhlin, Karen E. Alley, Carolyn Begeman, Øyvind Hegrenæs, Xiaohan Yuan, Alastair G. C. Graham, Kelly Hogan, Peter E. D. Davis, Tiago S. Dotto, Clare Eayrs, Robert A. Hall, David M. Holland, Tae Wan Kim, Robert D. Larter, Li Ling, Atsuhiro Muto, Erin C. Pettit, Britney E. Schmidt, Tasha Snow, Filip Stedt, Peter M. Washam, Stina Wahlgren, Christian Wild, Julia Wellner, Yixi Zheng and Karen J. Heywood, 31 July 2024, Science Advances.
DOI: 10.1126/sciadv.adn9188
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32 Comments
“This research is needed to understand the future of Antarctica’s ice sheet, …”
A minor point, but there isn’t just one ice sheet. The ice is a coalescent feature of many alpine glaciers from the interior. Only the western shelf ice is known to be melting. Thus, strictly speaking, they are learning things about the shelf ice that is melting, but not about the Eastern shelf ice. This distinction is important because it appears that there is considerable volcanic/geothermal activity in West Antarctica that is absent in East Antarctica.
All the sheets are melting from man made global warming, not from local activity. It is there in the text and in the paper:
“Changes in ocean temperature and circulation are driving mass loss from Antarctica through basal melting of floating ice shelves (1, 2). Ice shelf thinning and break-up reduce buttressing forces that hold back grounded ice (3), which may initiate feedbacks associated with grounding-line retreat (4), accelerating global sea level rise (5).”
First of all, this study is specifically about a study of just the Dotson Ice Shelf in West Antarctic.
However, to respond to your assertion that “ALL the sheets are melting from man made global warming,” take a look at the IceSat2-derived map showing melting for all of Antarctica and tell me is you are still willing to stand behind your assertion:
https://scitechdaily.com/images/Antarctica-Ice-Changes.jpg
Note that the melting is primarily shelf ice except in West Antarctica. If the melting were the result of “man made global warming,” wouldn’t you expect the melting to be uniform across the continent instead of being dominated by the sub-aerial melting in West Antarctica?
As you remarked below, “What has been claimed without evidence can be dismissed without evidence.” I also brought evidence.
From their article, “Basal melting is thought to be driven by relatively warm, salty, modified Circumpolar Deep Water (mCDW) that flows into the eastern part of the ice shelf cavity along the flank of a deep trough.”
Perhaps you could explain how anthropogenic surface warming is increasing the temperature of the Circumpolar Deep Water that is probably about 1,000 years old.
This was a 1950s sci-fi movie.
With the oceans full of plastics and industrial waste plus cruise ships dumping their toilets and garbage the common low level slobs don’t give a dam we should be putting all are brain power into the solar system moons and planets let the religious nuts who destroy are freedom and liberty and want to control are life’s.
Ray, check your grammar and spelling. It’s OUR oceans,OUR freedoms, etc.
Not everyone is a perfect speller, but still have the right to voice their opinions. We all need to embrace what other people think and feel, instead of nitpicking someones grammar. By the way, there were some punctuation errors that YOU missed. Sorry, just saying. Let us all take care of our planet, before it’s too late.
Have it.
I have to come in again because the last two is why were done I mean 80% of the scientist sold out for the cottages and all the University faculty 100% lined US up along side the ditches and pulled the trigger the ones who are with me were getting angry look out this November we are coming strong.
What religious nuts taking away your freedoms and liberty and for the record you’re lib nuts also go on these cruises…that help spew their crap into the oceans.. generally the lib nut and dems states seem to be the filthiest of current pollution stats states….oh California comes to mine…
Ray, Joe: What has been claimed without evidence can be dismissed without evidence.
You don’t live on a spinning ball…all “science” based on this is fraudulent crap ..
? Earth is rotating, hence day/night. But climate science is not concerned with such small environmental changes, it is safe from your confusion.
The human race will destroy itself. Humans are incapable of getting along with each other. Whether it’s grammar,or the shape of the rock we all live on.
Too bad for your analysis that the global trends are dropping rates of violence (wars, murders, et cetera).
400,000+ people murdered in Mexico in the past two decades. 1200 killed October 7, 2023 Western Negev, Israel. 30,000 killed Gaza Strip, October 2023 to present. Approximately 120,000 Russians killed and 70,000 Ukrainians killed from February 2022 to present (military losses only, not even including civilian dead). But, yes, U.S. homicide numbers dropped by 10% to 20% each of the past two years (after another major peak four years ago.) Oh well, as long as it happens outside the U.S. I guess you call that progress.
” But, yes, U.S. homicide numbers dropped by 10% to 20% each of the past two years (after another major peak four years ago.)”
That “another major peak” was about half of the 1993 peak, albeit that all the homicide rates in the USA are higher than they were in the 1950s.
My use of the words “another major peak” was based on the rate of increase and the actual number of deaths, not the rate per 100,000. The percentage jump in the number of homicides from 2019 to 2020 was almost 30%, the largest in 60 years. The actual numbers- 16,952 (2019) vs. 22,479 (2020). During the previous peaks in the early 1980’s and early 1990’s the average number of homicides per year was 24,000. In the early 2020’s it was 22,000. Six years prior in 2014 the number of homicides was just over 14,000. If you wat to compare the rate per 100,000 in 2020 vs. 1993 then, yes, it’s about one third lower (not half). If you disagree with my use of the words “another major peak” based solely on the homicide rate per 100,000, that’s fine. It matters little to me if those 20,000+ deaths came out of a population of 250 million or 300 million. Violence ebbs and flows in human history. Victims of war and murder should not be reduced to statistical theory. Actual numbers matter. That was the point I was trying to make in my reply to Torborg Larson’s comment.
Very interesting
You don’t argue with the mentally ill . You deny them rights every American citizen has to earn . First step in forming a structured government.
US is still a democracy and psychiatric conditions are not considered a general problem:
“Under federal law, a person cannot be barred from voting because of “incompetence” except in very limited circumstances. As a rule, if a person is competent enough to go to the polls and vote, or to complete an absentee ballot, federal law requires that the person be allowed to vote.”
And by the way we’re a republic not a democracy the Constitution needs to be reread not rewritten….
Unless you’re a felon 🤷🏼
Guess which party loves dismantling mental Healthcare. Answer Republitards , ” Gotta defund education too “
Relevance?
Wait a second, where the heck is West Antarctica anyway?
It’s on the side opposite East Antarctica.
OMG Just please bring on the asteroid.
The primitive mentality of mankind and the manipulation of it by the divisive and destructive ideology of their societal constructions, belief systems, and influential leaders will be the end of the creation. They hold the keys to their survival, but they must come to know themselves.
I’d like to think that mankind could at least agree on symptoms and work to quell them, while beliefs in causes differ, but it seems there is denial of symptoms even existing as well.
How do you propose to work to reduce symptoms if you don’t understand the cause of the symptoms? If you treat acute poisoning as if it were a bacterial infection, the treatment will be ineffective.