Researchers Find Major West Antarctic Glacier Melting from Geothermal Sources

Volcanoes hidden deep beneath the ice.

Press Release from the University of Texas:


Researchers Find Major West Antarctic Glacier Melting from Geothermal Sources

June 10, 2014 – AUSTIN, Texas — Thwaites Glacier, the large, rapidly changing outlet of the West Antarctic Ice Sheet, is not only being eroded by the ocean, it’s being melted from below by geothermal heat, researchers at the Institute for Geophysics at The University of Texas at Austin (UTIG) report in the current edition of the Proceedings of the National Academy of Sciences.

The findings significantly change the understanding of conditions beneath the West Antarctic Ice Sheet where accurate information has previously been unobtainable.

The Thwaites Glacier has been the focus of considerable attention in recent weeks as other groups of researchers found the glacier is on the way to collapse, but more data and computer modeling are needed to determine when the collapse will begin in earnest and at what rate the sea level will increase as it proceeds. The new observations by UTIG will greatly inform these ice sheet modeling efforts.

Thwaites Glacier - geothermal flow
This map shows the locations of geothermal flow underneath Thwaites Glacier in West Antarctica that were identified with airborne ice-penetrating radar. The dark magenta triangles show where geothermal flow exceeds 150 milliwatts per square meter, and the light magenta triangles show where flow exceeds 200 milliwatts per square meter. Letters C, D and E denote high melt areas: in the western-most tributary, C; adjacent to the Crary mountains, D; and in the upper portion of the central tributaries, E. Credit: University of Texas Institute Geophysics.

Using radar techniques to map how water flows under ice sheets, UTIG researchers were able to estimate ice melting rates and thus identify significant sources of geothermal heat under Thwaites Glacier. They found these sources are distributed over a wider area and are much hotter than previously assumed.

The geothermal heat contributed significantly to melting of the underside of the glacier, and it might be a key factor in allowing the ice sheet to slide, affecting the ice sheet’s stability and its contribution to future sea level rise.

The cause of the variable distribution of heat beneath the glacier is thought to be the movement of magma and associated volcanic activity arising from the rifting of the Earth’s crust beneath the West Antarctic Ice Sheet.

Knowledge of the heat distribution beneath Thwaites Glacier is crucial information that enables ice sheet modelers to more accurately predict the response of the glacier to the presence of a warming ocean.

Until now, scientists had been unable to measure the strength or location of heat flow under the glacier. Current ice sheet models have assumed that heat flow under the glacier is uniform like a pancake griddle with even heat distribution across the bottom of the ice.

The findings of lead author Dusty Schroeder and his colleagues show that the glacier sits on something more like a multi-burner stovetop with burners putting out heat at different levels at different locations.

“It’s the most complex thermal environment you might imagine,” said co-author Don Blankenship, a senior research scientist at UTIG and Schroeder’s Ph.D. adviser. “And then you plop the most critical dynamically unstable ice sheet on planet Earth in the middle of this thing, and then you try to model it. It’s virtually impossible.”

That’s why, he said, getting a handle on the distribution of geothermal heat flow under the ice sheet has been considered essential for understanding it.

Gathering knowledge about Thwaites Glacier is crucial to understanding what might happen to the West Antarctic Ice Sheet. An outlet glacier the size of Florida in the Amundsen Sea Embayment, it is up to 4,000 meters thick and is considered a key question mark in making projections of global sea level rise.

The glacier is retreating in the face of the warming ocean and is thought to be unstable because its interior lies more than two kilometers below sea level while, at the coast, the bottom of the glacier is quite shallow.

Because its interior connects to the vast portion of the West Antarctic Ice Sheet that lies deeply below sea level, the glacier is considered a gateway to the majority of West Antarctica’s potential sea level contribution.

The collapse of the Thwaites Glacier would cause an increase of global sea level of between 1 and 2 meters, with the potential for more than twice that from the entire West Antarctic Ice Sheet.

The UTIG researchers had previously used ice-penetrating airborne radar sounding data to image two vast interacting subglacial water systems under Thwaites Glacier. The results from this earlier work on water systems (also published in the Proceedings of the National Academy of Sciences) formed the foundation for the new work, which used the distribution of water beneath the glacier to determine the levels and locations of heat flow.

In each case, Schroeder, who received his Ph.D. in May, used techniques he had developed to pull information out of data collected by the radar developed at UTIG.

According to his findings, the minimum average geothermal heat flow beneath Thwaites Glacier is about 100 milliwatts per square meter, with hotspots over 200 milliwatts per square meter. For comparison, the average heat flow of the Earth’s continents is less than 65 milliwatts per square meter.

The presence of water and heat present researchers with significant challenges.

“The combination of variable subglacial geothermal heat flow and the interacting subglacial water system could threaten the stability of Thwaites Glacier in ways that we never before imagined,” Schroeder said.

For more information, contact: University Communications, Office of the President, 512 471 3151;  Anton Caputo, Geology Foundation, Jackson School of Geosciences, 512-232-9623.

http://www.utexas.edu/news/2014/06/10/antarctic-glacier-melting/

Thanks to Richard Knight for this link


32 thoughts on “Researchers Find Major West Antarctic Glacier Melting from Geothermal Sources”

  1. Not a damned thing anybody can do about it either. Maybe affected coastlines should be making changes that would mitigate any sea level rise from this melting ice.

    • Gary, that IS the $64,000 question. If the entire ice sheet is being melted from below, there isn’t anything that can be done to stop it – not driving electric cars, shutting down coal plants, investing in solar and wind technologies, or anything else. The planet is going to do what the planet wants to do. I don’t see all the fuss about spending trillions of dollars to change world society where any changes made aren’t going to amount to a hill of beans. All the modeling scientists have done still can’t account for the growth in sea ice, and having data with no solutions for how to adapt to changes (note I didn’t say stop, or mitigate, or reverse) that are inevitable is academic frivolity.

    • It won’t be enough to make any difference. As more ice melts, more moisture escapes into the atmosphere which in turn causes more cooling, more snow and more ice build up in other places. What you have with increased submarine vulcanism is a formula for more glaciation on land surfaces.

      • I was thinking similarly,
        it wont(probably) all slide in one huge hit, so the freshwater will be on top for the wind to pick up and help rise for more nice clouds and rain..
        so while this may in fact contribute to some sealevel rise it may be fairly slow and adaptable for us, IF we have the brains we were born with, and dont follow warmists panic panic!

        • Panic is what all too many people and organizations want for various reasons. For their political agenda(s). Panic sells newspapers, generates web hits and thus pays salaries and grant monies.

          Common sense solutions are boring so nobody much wants to hear about them.

  2. My goodness, what will the Global Warming-I mean Climate Change promoters do with theses findings? Probably blame the thermal conditions on Climate Change…there, that sounds about right!

  3. Interesting how they can’t get away from “warming ocean” even though the ice sheet is sitting on a “multi-burner stovetop” that is heating it from below. It is not possible to get away with attributing anything to a cause other than CO2. So sad for all of us.

  4. Maybe all those Warmists living on expensive coastal property should rethink their investments. Except, I find it hard to believe that a glacier the size of Florida would cause a sea level rise of even one meter, much less two. It doesn’t take rocket science to understand that the rest of the Antarctic ice is in no particular danger of melting any time soon. Just look at the temperature data, long or short term. Land-based ice just doesn’t melt in a place where the air temperature remains below zero degrees fahrenheit permanently. The only way to melt it is to build a fire under it. Calving is not melting.

  5. Looks more like they are trying to find another “scare the hell out of them” deal. The geothermal activities didn’t just start, they’ve been ongoing for ages, I am sure, so the purpose of this is to suddenly make everyone worry about the ice melt that is not happening at 50 below zero temperatures. as for the heat, 200 milliwatts per square meter doesn’t sound like enough heat to do serious damage, either, as I am sure the Sun puts down more than that on the top of that ice pack. I think they need more than just more computer modeling on this.

    • curious now..wonder what the heat output of the current iceland volcano was to get the ice above the caldera to subside, bet its mega times the heat:-)

  6. This potential calamity will, of course, be blamed on CO2 if the ice sheet collapses and raises sea levels a meter or more, and the public will never hear about the volcanoes under the ice sheet. (“Chicken Little was right!”)

    I also suspect that any warming on the western coast of the West Antarctic peninsula may also be primarily attributable to volcanic activity off that coast, in the chain of recently discovered (and very active) volcanoes that parallels the peninsula, not far offshore.

    This is purely anecdotal, but every time I have seen global ocean temperature anomaly maps in recent years, most of the southern ocean has been dark blue (colder than normal), except for a large patch of warmer water right where the chain of underwater volcanoes are found. Coincidence? Continued warming of that patch of ocean quite possibly could continue eating away at the periphery of the ice sheet, by raising both water and air temperatures locally on the peninsula.

    In short, even if we are plunging into a new Little Ice Age, it is quite possible that the combination of undersea and under-glacier volcanoes could cause a catastrophic collapse of the ice sheet, although the effects might be mitigated or overridden by growing snow accumulations in other areas of the planet.

    • I would have to counter this with the statement, where has the navy hidden its submarines in the southern oceans, and when or have they moved out of there yet? Remember atomic subs have been in operation since the 60’s. Their naval unit detection units even longer, They would have heard the hissing and rumbling, and looked to see what it was back when? I would say we have not had the full story yet. These scientists stumbled on something and got to make a paper on it. So what did they miss?

  7. Unless of course your an AGW fanatic who thinks atmospheric global warming can melt an immense ice cap from the inside out.

  8. If this process of geothermal warming has only started recently (which I don’t believe) it will most certainly stop as well like all other volcanic activities whereever in the world. I suppose this is a thing we only discovered recently and is already going on for a very long time. In both cases there is no threat of sea level rising. So nothing to worry about.

  9. I believe the amount of water within the Thwaite glacier is vastly overestimated and is used to freak out the people….Fine conditions near the glacier are warming naturally but and there is a big BIG but here since the Antarctic in general is cooling and is really for 9 months out of the year in the deep freezer wouldn’t this water just refreeze once its past the geothermal influence of whatever that glacier is doing and thus just make the sea ice thicker and really nothing else

  10. Now what are the Global Warming-I mean Climate Change supporters going to do with these findings? Perhaps blame it on Climate Change…there, that sounds about right!

  11. I get fed up hearing such bull as if the western peninsula is the whole of Antarctica yes the larsen ice sheet colapsed but what these climate change liars dont mention is mean global ice levels are roughly the same as they was 35 years ago when records began…its just the antartica has grown the north pole sea ice hasn’t. what gets me is how 35 years is a trend when we don’t even know what polar sea ice levels where like for most of the 19th and 20th centuries oh but the whole of Antarctica is melting from underneath these people say when in reality its the tiny western part that is (which is far more open to the sea than the rest of the continent) also there is evidence of volcanic activity under the sea there.

  12. Good grief this is not really new. The area is full of volcanoes.

    July 11, 2011 Huge Underwater Volcanoes Discovered Near Antarctica “A string of a dozen volcanoes, at least several of them active, has been found beneath the frigid seas near Antarctica…The find backed up reports from a ship that visited the area in 1962, which indicated a hidden volcano had erupted in the region…”

    November 18, 2013 Active Volcano Found Under Antarctic Ice: Eruption Could Raise Sea Levels

    In January 2010, scientists set up a series of seismometers, or earthquake detectors, on Marie Byrd Land, a highland region of West Antarctica.

    The instruments array detected two swarms of earthquakes about one year apart, in 2010 and 2011. The earthquakes were small, with magnitudes of between 0.8 and 2.1.

    The tremors occurred at depths of about 15 to 25 miles (25 to 40 kilometers), close to the boundary between the crust and the mantle, and much deeper than normal crustal earthquakes.

    The depth at which the quakes occurred, as well as their low frequency, suggests they might be so-called Deep Long Period earthquakes, or DPLs, which occur in volcanic areas….

    the heat from the volcano could increase melting at the base of the glacier and meltwater could act like a lubricant that makes the overlying ice flow out to sea faster…

    “This volcanic complex has been operating for millions of years …

    Most of the seismometers used to discover the volcano have been removed and installed in other areas in Antarctica, so further study of its seismic activity is no longer possible. [Hide the evidence?]

    MORE: Seismic detection of an active subglacial magmatic complex in Marie Byrd Land, Antarctica “Numerous volcanoes exist in Marie Byrd Land, a highland region of West Antarctica. High heat flow through the crust in this region may influence the stability of the West Antarctic Ice Sheet… these observations provide strong evidence for ongoing magmatic activity and demonstrate that volcanism continues to migrate southwards along the Executive Committee Range.”

    Marie Byrd Land is the portion of West Antarctica lying east of the Ross Ice Shelf and the Ross Sea.

    Velocities of Thwaites Glacier and smaller glaciers along the Marie Byrd Land coast, West Antarctica

    Abstract:

    Average velocities for time intervals ranging from <1 to 15 years were measured by tracking ice-surface patterns on sequential Landsat and European Remote-sensing Satellite synthetic aperture radar images. Velocities of Thwaites Glacier range from 2.2 km a-1 above the grounding line to 3.4 km a-1 at the limit of measurements on Thwaites Glacier ice tongue. The glacier increases in velocity by about 1 km a-1 where it crosses the grounding line. Over the period 1984-93, Thwaites Glacier ice tongue accelerated by about 0.6 km a-1. Velocities of the floating part of several minor glaciers and some ice shelves are also determined: Land Glacier, 1.7-1.9 km a-1; DeVicq Glacier, 0.7-1.1 km a-1; Dotson Ice Shelf, 0.2-0.5 km a-1; Getz Ice Shelf, 0.2-0.8 km a-1; and Sulzberger Ice Shelf, 0.01-0.02 km a-1. The high velocities along the Marie Byrd Land coast are consistent with the high precipitation rates over West Antarctica and, for some of the glaciers, the lack of buttressing ice shelves.
    1998
    Page Last modified: 09/16/2014

  13. In the unlikely event of large areas of the Thwaits Gathier completely melting, the sea level would not be altered much because the landmass has been eroded down well below sea-level. Some of the Pig Island/Thwaits ice sheet region has a depth of >1 km below current sea level. As the ice melts and contracts, some of the volume of ice effectively disappears into the sub sea level part. A 2000m deep ice sheet becomes ~1850m of water with 1000m of that being already below to-day’s sea-level.
    Histrionic language such as “collapse of the glacier” suggest sudden changes when in reality these things are shown to be slow and variable. As someone else pointed out, during the long dark winter not much melts in Antarctica.
    All that is happening is that the base of the ice sheet which melts under the immense weight and sliding motion of the ice pressing on the rock, is being assisted by geothermal factors in certain areas.
    Catastrophy post-poned, -yet again.

    • Thanks for posting this. It mentioned in the article some of the ice was pushed as much as 2km below sea level – if that is the case if it melts sea levels should drop. It would only cause a rise if ice and snow not already in the water/ not already below sea level were to also slide in at an accelerated rate for no apparent reason.

  14. University of Texas, huh?

    In warmist speak, ” This travesty came from an university in a state that supports oil production, and hence carbon pollution. So they need to be ignored as they are obviously on Big Oil’s payroll”

    Thankfully Darwin seems to be kicking in.

    It’s survival of the fittest, prep for cold weather. You’ve been informed.

    • Yup, this is old news, so please, please, please just forget about it. Nothing to see here folks, just move along. We wouldn’t want folks to start thinking that the ice is melting due to natural forces, would we?

  15. Known physics: Put a cube of ice in a glass of water and see that the level of the water doesnt rise when its melted..call them scientists..couldnt pass grade school! And yet this whole ice sheet will raise the entire oceans when it melts..Even if its land bound and does add to the ocean volume..Do any of these idiots actually know the NUMBERS of cubic km of water there are in the oceans? compared to the volume of that glacier.

  16. Its interesting to read the Mouginot et al (2014) paper in GRL 41. In the abstract and elsewhere, they talk about instability; however, if one looks at Fig.4, the combined acceleration of all WAIS glaciers is close to zero. The Thwaites glacier, the second largest, is still accelerating – perhaps geothermal is the reason.

  17. If the increased vulcanism on land is caused by the gradual decline/reversal in the earth’s magnetic field, then we should expect increased vulcanism both under the oceans and under the polar icecaps. Also, as the volcanic heat warms the oceans from below, this ever so slightly warmer water would melt the glaciers that protrude from land into the sea. Meanwhile the colder air above freezes the sea surface, increasing the area of floating ice. Robert, your predictions are being borne out.

  18. http://news.agu.org/press-release/elephant-seals-help-uncover-slower-than-expected-antarctic-melting/

    “From the “seal data”, the scientists accumulated enough knowledge concerning the area’s water circulation and how it changes over the seasons to construct the most complete picture of what and how the Fimbul Ice Shelf is melting from the bottom up.

    It turns out that past studies, which were based on computer models without any direct data for comparison or guidance, overestimate the water temperatures and extent of melting beneath the Fimbul Ice Shelf. This has led to the misconception, Hattermann said, that the ice shelf is losing mass at a faster rate than it is gaining mass, leading to an overall loss of mass. The model results were in contrast to the available data from satellite observations, which are supported by the new measurements.

    The team’s results show that water temperatures are far lower than computer models predicted, which means that the Fimbul Ice Shelf is melting at a slower rate. Perhaps indicating that the shelf is neither losing nor gaining mass at the moment because ice buildup from snowfall has kept up with the rate of mass loss, Hattermann said”

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