Advertisements

The Great Totten Glacier is Floating on More Warming Water Than We Thought

It’s well known now that massive glaciers in Greenland and Antarctica are contributing to an accelerating global sea level rise. And while we first thought Greenland was primarily at risk of producing ocean-lifting melt this Century, we have now learned that both West and East Antarctica are becoming involved.

(A massive glacier the size of France is floating on more of a warming ocean than previously thought. Taking into account past reports of thinning along the glacier’s underside, and this is a rather concerning finding. Image source: Australian Antarctic Division.)

How much and how soon and under how much warming pressure is still a matter of some debate in the sciences. But the situation is now looking a bit worse for the Totten Glacier — an enormous sea-fronting slab of ice as big as France that if it melted in total would, by itself, raise sea levels by about 10-13 feet globally.

Previously thought to be more resilient to melt as a result of human-caused climate change and related fossil fuel burning, the Totten was once considered to be stable. However, over recent years, concerns were raised first when plumes of warm water were identified approaching the glacier’s base and later when it was confirmed that Totten was melting from below. Concerns that were heightened by new research identifying how winds associated with climate change were driving warmer waters closer and closer to the huge ice slab.

(Winds heated by climate change drove warmer waters toward Totten and accelerated the glacier during recent years. Video source: Science News.)

After follow-on expeditions to Totten, scientists (over the past two years) discovered that the glacier’s floating underside was losing about 10 meters of thickness annually even as its seaward motion was speeding up. Now, new research has found that more of the Totten Glacier is floating upon this warming flood of ocean water than previously thought. According to Professor Paul Winberry, from Central Washington University, who spent the austral summer of 2018 with a Tasmania-funded team of scientists taking measurements of Totten:

“A hammer-generated seismic wave was used to ‘see’ through a couple of kilometres of ice. In some locations we thought were grounded, we detected the ocean below indicating that the glacier is in fact floating (emphasis added).”

Beneath Totten lies a large ridge upon which most of the glacier is grounded as it flows toward the sea. But penetrating this ridge are numerous gateways that, if melted through, provide sea water access to the glacier’s interior. And recent studies have found that a number of these gateways have been thawed open, allowing warming ocean waters access to sections of the glacier that are hundreds of miles inland.

(Warm water invasion pathways have opened along Totten’s previous grounding line. These openings have allowed water to flood far inland beneath the glacier. The result is a less stable, more rapidly moving ice sheet. Image source: Jamin Greenbaum/University of Texas-Austin.)

This warm water breakthrough has contributed to Totten’s seaward movement. And the new study was aimed at discovering the extent of the inland water melt flood. According to lead researcher Dr Galton-Fenzi:

“These precise measurements of Totten Glacier are vital to monitoring changes and understanding them in the context of natural variations and the research is an important step in assessing the potential impact on sea-level under various future scenarios.”

The fact that the extent of inland flooding along Totten’s underside runs further than previously thought is a concern in light of recent findings that the glacier is losing a considerable amount of underbelly ice each year. In addition, the fact that we haven’t yet pinpointed the grounding line should add another note of worry. How much we should worry is unclear at this time. But the fact is that the scientific signs coming in from Totten continue to indicate that the glacier is suffering warming impacts that pose risks to its historic stability.

Advertisements
Leave a comment

26 Comments

  1. Spike

     /  March 20, 2018

    Another event that is progressing “faster than expected” – if indeed it was expected at all this early in the ascent of global temperature. Glad you picked this up and covered it Robert.

    Liked by 1 person

    Reply
    • I remember when we were writing about this in 2013 and people were speculating about water moving through the gaps in the initial grounding line to run far inland. Well, it appears that started to happen in the mid 2000s with quite a bit more occurring post 2015. Looks like a mess in the offing to me.

      Liked by 1 person

      Reply
  2. The Arctic’s carbon bomb might be even more potent than we thought
    https://www.washingtonpost.com/news/energy-environment/wp/2018/03/19/the-arctics-carbon-bomb-might-be-even-more-potent-than-we-thought/

    Research released Monday suggests that methane releases could be considerably more prevalent as Arctic permafrost thaws. The research finds that in waterlogged wetland soils, where oxygen is not prevalent, tiny microorganisms will produce a considerable volume of methane, a gas that doesn’t last in the air much more than a decade but has a warming effect many times that of carbon dioxide over a period of 100 years.

    “What we can definitely say is that the importance of methane was underestimated until now in the carbon studies,” said Christian Knobloch, a researcher at Universität Hamburg in Germany and the lead author of the study, published in Nature Climate Change.

    The divergent finding came after Knoblauch and his colleagues conducted a lengthy experiment, more than seven years long, monitoring patches of submerged and artificially warmed soil from Siberia in the laboratory, and gradually seeing sensitive methane-producing microorganisms become more prevalent over time.

    Knoblauch contends that other studies have not examined waterlogged Arctic soils for as long, and he notes that in some cases it took three years or more for the methane-generating microorganisms to really get cranking.

    “What we saw is that it takes a very long time until methane starts being produced, and the study that we did is really the first one which is so long,” Knoblauch said.

    Liked by 1 person

    Reply
    • For those who get blocked by the pay wall, right click on the link and choose “Open link in incognito window.”

      Like

      Reply
    • Finally, something that I can work with on this issue. In essence, the study points to an approximate potential feedback of 3.5 to 4 billion tons of CO2 equivalent emissions from the Arctic each year averaged per year until 2100. This is a feedback equivalent to approximately 1/3 present human carbon emissions.

      If this study is correct, it lends urgency both to present carbon emissions reduction efforts and to follow-on effort for atmospheric carbon capture — making those efforts more necessary.

      At this point, I feel like I can finally add further comment to the Arctic methane monster issue. However, we should be clear that this is one study that will require further confirmation.

      Liked by 1 person

      Reply
    • bostonblorp

       /  March 21, 2018

      The circumstances aren’t exactly the same but it was the methane release caused by the rise in CO2 that made the Permian mass extinction so apocalyptic. Every time I read about sea temps being some outrageous amount above normal I wonder how the clathrates and other methane stores are doing.

      Is anyone doing any cocktail napkin scribbles about atmospheric CH4 capture? CO2 is measured in ppm, CH4 in ppb. Can’t be easier.

      Like

      Reply
  3. kassy

     /  March 20, 2018

    Yeah quite.

    So the glaciers will keep on melting (see comment section of previous article) but their contribution to sea level rise is a slow trickle.

    Then Greenland is not doing to well which is more of a worry because it causes bigger jumps when things go wrong.

    And now this. Those antarctic glaciers are so huge they cause even bigger jumps.
    I think it is a fair bet to say we do not have good data on the grounding lines of many glaciers there. We have no good idea how much melt we already have committed to.

    We measure all these things and we also know there is no way we can stop the melt except reducing our greenhouse gas emissions a.s.a.p.

    Which we should do if only for our kids.

    Like

    Reply
    • rhymeswithgoalie

       /  March 21, 2018

      “We measure all these things and we also know there is no way we can stop the melt except reducing our greenhouse gas emissions a.s.a.p.”

      We may be nearing (if not past) the point where merely *reducing* GGs is enough: We’re going to have to start actively pulling large amounts of carbon out of the atmosphere.

      Like

      Reply
  4. Hi. Thanks for the info. So not enough data yet to know timescales, however ‘size of France’ and ’10 to 13 feet’ are significant. It constantly amazes me how stories/facts like this aren’t covered more in the mainstream media, and how we carry on regardless. It appears that most people will only make a change if they’re really forced too, and by that time it’ll be too late. We really are a suicidal species; so much potential and yet we squander it, often at the whims of relative few.

    Liked by 1 person

    Reply
    • I think that given the fact that this is an out of context issue, most people lack the needed psychological equipment to cope with difficult news on this scale. The inertia that is resistant to change — to individual behavior and society’s is vast. We just have to keep chipping away at that block if we are going to make much progress.

      Liked by 2 people

      Reply
      • You took the words out of my mouth; the psychology of it is fascinating. I am not afraid to admit that at times I find it overwhelming and that I’m in danger of disappearing down a rabbit hole. Keep chipping away!

        Like

        Reply
        • Stephen Hawking:

          “As long as there is life, there is hope.”

          But what we need here is courage. Courage to do the right thing. Courage to face down what at first will appear to many as an insurmountable challenge. But it was challenges like these that we were born for. This is a challenge that humankind can face so long as we conjure the better angels of our nature.

          Liked by 2 people

  5. Jeremy in Wales

     /  March 20, 2018

    Just re-posting this, as this is another paper supporting the basal melt:

    Article on the basal melting of the Totten Glacier derived from in situ measurements
    http://advances.sciencemag.org/content/2/12/e1601610.full

    A recent view on EOSDIS Worldwide shows the Totten with a large polynya in front of the ice shelf.
    https://go.nasa.gov/2tHBM5F

    It is warm (0.4°C) ocean waters doing the damage. Even if CO2 emissions trend downwards the oceans will continue to warm and this melting will extend.

    Like

    Reply
    • We’ve locked in a certain degree of melt. But how much we ultimately melt is directly dependent on how much fossil fuels we burn. So to say that ‘even if CO2 emissions trend downwards the oceans will continue warm and melting will extend’ is not to tell the whole story. The whole story is that you are looking at feet of additional sea level rise if you halt fossil fuel burning soon and under the best case scenario. If you keep burning fossil fuels you are looking at scores of feet of additional sea level rise ultimately.

      One of these things is not like the other.

      Like

      Reply
      • Jeremy in Wales

         /  March 20, 2018

        and that is the 64 trillion $ question, when can we bring emissions to zero? There are signs that renewables and electric transport is ramping up, such as in India, as you re-tweeted

        2050 seems wholly inadequate and 2030 seems currently unlikely unless the political climate changes. Hanson, I believe, thinks to stabilise the situation we need to reduce the atmospheric concentrations to 350ppm, ie negative emissions
        https://www.earth-syst-dynam.net/8/577/2017/esd-8-577-2017.pdf

        But you are right to give time to the more positive message, renewables, electric cars etc as the message is far more positive than even 3 years ago.

        Like

        Reply
        • With renewables we can bring emissions to zero or near zero. We need atmospheric carbon capture to get to the needed goal of net negative. And we can do that too. But the low hanging fruit right now is renewables.

          Liked by 1 person

  6. I thought floating ice melting does not contribute to sea level rise?

    Like

    Reply
    • IF it was first attached to land and then it starts floating in the ocean because the ocean invaded underneath, then yes, it does. Ice already floating on the ocean doesn’t contribute to sea level rise because it’s already in the ocean. But add a high volume of ice and, well, you can use common sense to determine the rest.

      Liked by 1 person

      Reply
  7. kassy

     /  March 20, 2018

    The floating antarctic ice is holding back the ice on the continent. As long as it is there it will not run off into the sea. But when the sea ice is gone the ice that was on land will just slide into the sea.

    In this case a lot more of the sea ice bottom is exposed to melt by relatively warm water then we thought would be exposed meaning it will melt quicker.

    The sea ice near Antarctica is the fuse, the land ice is the bomb.

    Like

    Reply
  8. Kiwi Griff

     /  March 21, 2018

    Hot summer catastrophic for New Zealand glaciers

    University of Canterbury researchers monitoring glacier mass have confirmed that this summer’s extreme heat has been catastrophic for New Zealand’s alpine glaciers.

    A team from the University of Canterbury, led by glaciologist and Geography senior lecturer Dr Heather Purdie, hiked into the Rolleston Glacier in Arthurs Pass National Park for their annual end-of-summer glacier survey.

    The UC researchers found that as a consequence of this summer’s extreme heat, the Rolleston Glacier has lost nearly all of the snow that accumulated on the glacier during the previous year.

    “This is likely the most negative mass balance year ever recorded on this glacier,” Dr Purdie says.

    “Glaciers are great indicators of climate change. This summer was very warm and as a consequence New Zealand alpine glaciers are in very bad shape – they have lost a huge amount of snow and ice to melting over the summer.”

    Dr Purdie and adjunct geography academic Dr Tim Kerr, with the help of volunteers, have regularly measured the Rolleston Glacier since 2010. Each year they hike into the glacier at the end of winter and again at the end of summer to dig snow-pits, measure snow depth, and install stakes that measure how much snow and ice melts off the glacier during the summer.

    This year the survey revealed that nearly all of the previous season’s snow had melted off the glacier. The team also recovered monitoring stakes that had been buried in the glacier back in 2014.

    “This was significant as it indicates that during this summer not only has the glacier lost all of last winter’s snow, but also snow that had accumulated on the glacier in previous years,” Dr Purdie says.

    “The only snow left on the Rolleston Glacier was snow that had avalanched down onto the glacier from the surrounding mountain peaks. Without this avalanche input, the glacier would have had no snow left at all.”

    http://www.voxy.co.nz/national/5/306447

    Like

    Reply
  9. Erik Frederiksen

     /  March 23, 2018

    Totten Glacier has about 50km to retreat slowly up a prograde bed before the bed turns retrograde and in the words of Eric Rignot, “All hell breaks loose”.

    Like

    Reply
  10. Mark Behrend

     /  April 7, 2018

    There seems to be a conscious attempt to bury the news that we are fast approaching a global Pearl Harbor of the environment. Last week’s UN report predicting hundreds of millions of starvation refugees by mid-century, for instance, got 3 minutes on BBC, a belated, oblique reference on France 24, and not a word on NPR or Yahoo News. The reason, I suggest, is that the powers that be have no answers, and fear that the truth would trigger worldwide panic today, instead of 30 years from now, when the monster at our doorstep. Acting now, when we might do something, you see, might disrupt the economy, which lives by the current fiscal year. The future is the our grandchildren’s problem.

    Liked by 1 person

    Reply

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Advertisements
%d bloggers like this: