Doomsday Glacier melting in Antarctica means terrible news for global sea level rise

News
By Robert Lea
published

The collapse of the glacier could trigger a chain reaction leading to the collapse of surrounding glaciers.

The Thwaites Glacier in Antarctica is sometimes called the Doomsday Glacier as its collapse could destabilize other glaciers in West Antarctica, leading to potential 10 feet (3 meters) sea level rise.
The Thwaites Glacier in West Antarctica is melting in hidden ways that could lead to its fast collapse. (Image credit: NASA)

The Thwaites Glacier in Antarctica, also known as the Doomsday Glacier, is melting in unexpected ways that could lead to its rapid collapse, a new study has revealed. 

Two teams of researchers have used an underwater robot and drilled deep holes into the Florida-sized Thwaites Glacier to study its melting patterns in unprecedented detail.

The researchers from the International Thwaites Glacier Collaboration discovered that while the overall melting of ice is slower than expected, melting in cracks and crevasses and other vulnerable areas is proceeding much more rapidly. The Thwaites Glacier is often called "the Doomsday Glacier" because its collapse could cause catastrophic sea level rise. 

"Our results are a surprise but the glacier is still in trouble," British Antarctic Survey oceanographer and research team member Peter Davis, said in a statement. "If an ice shelf and a glacier is in balance, the ice coming off the continent will match the amount of ice being lost through melting and iceberg calving. What we have found is that despite small amounts of melting, there is still rapid glacier retreat, so it seems that it doesn't take a lot to push the glacier out of balance."

Related: 10 devastating signs of climate change satellites can see from space

Thwaites Glacier is located in West Antarctica and covers 74,000 square miles (192,000 square kilometers). One part of the glacier juts out into the ocean and holds back the rest of the ice-mass that lies on bedrock, thus preventing it from slipping from the land to the sea.

Because the Thwaites Glacier slopes down towards the sea, it is particularly susceptible to climate and ocean temperature changes that could lead to rapid and irreversible ice loss. The collapse of Thwaites would cause seawater levels to rise by around 2 feet (65 centimeters). This could, in turn, destabilize neighboring glaciers, potentially increasing future sea levels by almost an additional 10 feet (3 meters).

To assess the Thwaites Glacier's vulnerability to collapse, the two groups observed ice melt rates and the properties of the glacier and its surrounding ocean by lowering instruments via a 1,925 feet (587 meters) deep hole drilled into the ice and by launching a torpedo-shaped underwater robot called Icefin under the glacier.

Icefin is particularly useful for investigating the grounding zone of Thwaites, the point at which the glacier touches the ocean floor, which has previously been almost impossible to study. The grounding zone of this glacier has retreated by 8.7 miles (14 kilometers) since the 1990s, making Thwaites one of the fastest-changing glaciers in Antarctica. The factors causing this retreat are, however, poorly understood.

The new data provides a clearer picture of the changes taking place under Thwaites, revealing that ice in cracks across the glacier is melting quickly. Melting in cracks and crevasses is potentially dangerous because as water funnels through them, heat and salt can be transferred into the ice. This can result in the widening of these crevasses, causing large rifts in the ice shelf. Cracks and crevasses weren't the only area of the shelf experiencing rapid melting, however. 

Related stories:

— Wow! Iceberg larger than London breaks off Antarctica (photos)

— Greenland's glaciers are melting 100 times faster than estimated

— Antarctica's Denman Glacier is sinking into the world's deepest canyon

While a layer of cold fresh water below the bottom of the ice shelf and above the underlying warm ocean is slowing the rate at which the flat parts of the ice shelf melt, the team was shocked to discover that melting across the bottom of the ice shelf has created a staircase-like formation. In these staircase-shaped regions, called terraces, the ice of Thwaites is also melting rapidly.

The melting of ice in these terraces, cracks, and crevasses may become major factors in the loss of ice from Thwaites in the future, especially as major rifts progress across the ice shelf. This means these features may become the primary trigger for ice shelf collapse at Thwaites.

"These new ways of observing the glacier allow us to understand that it's not just how much melting is happening, but how and where it is happening that matters in these very warm parts of Antarctica," Cornell University researcher and Icefin team member Britney Schmid said. 

The research is published across  two papers both featured in the journal Nature.

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Robert Lea
Robert Lea
Senior Writer

Robert Lea is a science journalist in the U.K. whose articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University. Follow him on Twitter @sciencef1rst.

15 Comments Comment from the forums
  • murgatroyd
    If this headline does not get at least Honorable Mention in the 2023 Clickbait Awards, sub-category Climate Fear Porn, there is no justice in this world. :D
    Reply
  • PuritanDuaneLinn
    Oy.

    Spinning ball on a tilt won't throw water, but a chunk of ice will be catastrophic to sea levels?

    Got it. 🤣
    Reply
  • Ken Fabian
    It is good that Space.com treats reality seriously. Given the reality and seriousness of global warming it is important to understand how Antarctic ice sheet loss can and will contribute to sea level rise, which will increasingly impact people living in low lying places. And progressively impact places that are currently not at risk of inundation.
    Treating a profound problem of global scale that will seriously harm our capacity for enduring prosperity in irreversible ways like it is serious isn't "climate porn".
    Reply
  • CaptCook
    You can tell a lot about a theory by how it responds to its predictions being tested.
    This seems like an easy one: Glaciersmelts=2foot sea level rise.
    Ready… set… test!
    Reply
  • Warhammer420
    What a lie ... Al Gore propaganda is ridiculousness at it's finest. Climate change is just a ridiculous statement that ignorant people can't grasp. The earth has gone through multiple changes throughout Earth's geological history. Most of which is due to Solar Maximum and Minimum activities. And pole shift events that were way before any industrial pollution supposedly causing all this. It's just plain naturally occuring. Stop trying to fear monger people who probably got C's and D's in science class. Who believe anything their told by supposed experts on the subject. Pick up a book for God's sake, and practice REAL SCIENCE and research. Doomsday glacier sure , but it'll be hundreds of not thousands of years from now.
    Reply
  • murgatroyd
    It's so easy to signal that you belong to the "right" set of people -- the virtuous, the altruistic, the "follow the science" crowd. Just knock off a couple of lines of pompous blathering while trampling all over the scientific method. It gives meaning to your otherwise pathetic, miserable life bereft of accomplishments.

    I wish I could simply ignore you clowns, but unfortunately you just won't leave me alone. So I will keep skewering your bombastic "doomsday" language and I will keep mocking you, for mockery is the best weapon currently available against you. Screw you if you cannot handle it.
    Reply
  • Unclear Engineer
    It is amusing to see people posting about "natural cycles" as a reason to not believe that sea level will rise. The geologic evidence of the high point in those natural cycles 120,000 years ago indicates that sea level rose, with no human causes, to a level 25 feet higher than it is, today. So, no matter what you think the cause is, there is no good reason to expect sea level to not rise a lot in our future. How fast it does so, and when it will stop, are the main questions. Other warm periods in the last few million years have resulted in max sea level rises of as much as 65 feet higher than now. And, back several million years, before the current series of ice ages and warm periods started, sea level was hundreds of feet higher than it is now. If all of the ice caps and glaciers melt, sea level will be about 330 feet higher than it is right now.

    So, this article is just looking at some of the melting mechanisms for one glacier at one point in time. And, it doesn't say how fast it is predicted to happen. So, not really much useful info. In fact, it seems to indicate that humans might somehow stop the melting.

    Probably not. Much of the melting is due to the cycles of the Earth's orbital precession and axis tilt precession. And the current parts of those cycles are heading towards more warming in the Antarctic and less in the Arctic.

    So, in reality, we need to be planning for substantial sea level rise even as we try to cut our human effects on the climate.
    Reply
  • Ken Fabian
    Unclear Engineer said:
    In fact, it seems to indicate that humans might somehow stop the melting.
    Every low sea level rise projection depends on success at emissions reduction with minimum of delay. Glacier and ices sheet mass loss acquire a momentum that makes stopping them (by reducing human-made climate forcings) progressively more difficult in the early stages and effectively impossible later. The collapse of Thwaites would take us into too late to stop territory. But not too late to make things worse, by confusing too late to stop happening with can't prevent more and worse.

    Unclear Engineer said:
    It is amusing to see people posting about "natural cycles" as a reason to not believe that sea level will rise.
    Past climate changes provide examples of both how susceptible and how world changing climate change can be. They aren't evidence that current warming is natural or harmless. Climate science deniers are often unmoved by facts or reason and ultimately descend into conspiracy theories - because how else can every science agency that studies climate keep saying it is real and very serious? And get all those satellites that show evidence of a warming world to agree too? Even Intelligence Agencies - that appear to agree the science is sound and the climate problem is serious - are in on it?

    Sorry the real conspiracy is to sustain an ongoing absence of inconvenient responsibility or accountability for the biggest human-made waste stream - CO2 - and the problems it causes. Conspiracy theories that seek to blame the messengers - scientists, science agencies and those taking them seriously and calling for appropriate government coordinated national and international responses. Those taken in by it don't amuse me.

    Unclear Engineer said:
    Much of the melting is due to the cycles of the Earth's orbital precession and axis tilt precession.
    Where did you pull that out of?
    Reply
  • Unclear Engineer
    Unclear Engineer said:
    Much of the melting is due to the cycles of the Earth's orbital precession and axis tilt precession.

    Ken Fabian said:
    Where did you pull that out of?

    Ken , the intent of that particular sentence in my post was a response to the previous posts that talked about other natural cycles (e.g., "Solar Maximum and Minimum activities. And pole shift events"), which have little-to-nothing to do with global climate. Yes, there are theories that somegthing like a grand solar minimum might trigger an ice age, but even if true, it would be in relation to the climate being set-up for it by the Milankovitch Cycles in the Earth's orbital and rotational precession patterns.

    And the point I was trying to make is that, if somebody really is a believer in the effects of the natural cycles playing a role in how the climate is warming, today, then he/she should note that those cycles are currently shifting towards more solar energyt going into Antarctica and less into the Arctic at this time and into the future for quite a while. So, the conclusion should still be that the sea level is going to rise due to melting of Antarctic glaciers. How the specific glaciers behave is just details of the overall process.

    So, yes, the article was click-bait in the way it is worded. And the implications of the wording, that we might be able to stop the process, seems unproven and unlikely, at this point. And the timing was not quantitatively predicted in the article. I will note that the latest "best guesses" published elsewhere are showing a higher sea level in the next 30 years than previously estimated. So, there is some concensus building that the rate of sea level rise will be accelerating shortly by noticeable amounts.

    I am not arguing that humans aren't contributing to the projected acceleration of the sea level rise rate. I am just arguing that we need to stop publishing articles that imply we can stop the rise if we just do .

    Frankly, I think it is probably better communication of the reality and severity of the sea level situation for the governments to be seen to be actively planning for that future, instead of just using it as a scare tactic and implying that the whole thing can be avoided. My own planning is that my present home may become unlivable with greater and greater probability over the next few decades, with the actual transition date depending on when a hurricane with the actual devastating effects hits here instead of somewhere else. It could happen this summer . It probably will happen in the next 30 years.

    Anyway, sea level rise is not the only effect we need to worry about happening due to global warming. It is just the easiest one to predict and measure. Looking at atmospheric pattern changes is more complicated because there are many other short-to-medium-term changes adding "noise" to the trend lines. For instance, the Anaszi culture in the U.S. southwest seems to have been extinguished by a centuries-long shift in rainfall in that region, long before the industrial revolution. So, it is difficult to look at the current drought in the southwest as clearly due to global warming caused by humans. Hard to prove it is or is not.
    Reply
  • Ken Fabian
    Unclear Engineer said:
    I am not arguing that humans aren't contributing to the projected acceleration of the sea level rise rate. I am just arguing that we need to stop publishing articles that imply we can stop the rise if we just do .

    So, without any evidence you want to claim that Milankovitch cycles - that act very slowly over 10's of thousands of years - are responsible for significant changes to Antarctic ice sheets within the last century, that they are a significant factor in the current observable rapid acceleration of ice mass loss. You are arguing without evidence that there is a significant natural component to Antarctic ice mass loss, that therefore attribution to human causes is exaggerated.

    The "agenda" is preventing economically and environmentally damaging climate change.

    Sure, if you hand the issue over to others who do have other agendas in "you care so much, you fix it" style you can conveniently argue it is their other agendas that prevents you from supporting commitments to mitigate the problem but the science based advice has been the same advice irrespective of political leanings. By choosing to face up to it head on you can promote the means you think best - including your own agendas. No-one is stopping you.

    Climate activism only leans green and left because of failure of those who don't lean green or left to participate constructively - and chose instead to oppose and obstruct. That opposing hasn't been to prevent unreasonable left leaning extremism but to prevent legitimate accountability applying to commerce and industry.
    When those who lean right come out from behind the Wall of Denial and face up to the climate problem with eyes open, head on, we will begin seeing more constructive climate policies that are much more effective.
    Reply