Evidence of Recent Volcanic Eruptions Under the Western Antarctic Ice Sheet

Guest post by David Middleton

The discovery of volcanoes under the Antarctic ice sheet may be old news, but now we have evidence that at least some of them have recently (geologically speaking) erupted…

The First Solid Evidence of Eruptions Under Antarctic Ice

By Ross Pomeroy
September 14, 2017

In August, researchers at Edinburgh University announced that frigid West Antarctica is home to at least 138 volcanoes, all concealed within an ice sheet that’s up to two kilometers thick in some places!

The finding left Robert Bingham, one of the study’s authors, with an urgent question.

“The big question is: how active are these volcanoes? That is something we need to determine as quickly as possible,” he told The Guardian.

“If one of these volcanoes were to erupt it could further destabilise west Antarctica’s ice sheets. Anything that causes the melting of ice – which an eruption certainly would – is likely to speed up the flow of ice into the sea.”

Luckily, Bingham didn’t need to wait long for an answer. A team of scientists from New Mexico Tech, Dartmouth College, and Vermont Technical College has uncovered evidence of volcanic eruptions in ice cores taken from the West Antarctic ice sheet (WAIS). A paper describing their findings has just been published in Scientific Reports.

Nels Iverson, a PhD Candidate in Geochemistry, and his team examined an ice core situated near two known volcanoes in the ice sheet, Mount Thiel and Mount Resnick. Utilizing scanning electron microscopy and electron microprobe analysis, they found thick layers in the ice core dating back 22.3 thousand years and 44.8 thousand years. These layers were filled with tephra, rock fragments and particles ejected by volcanic eruptions (see figure below).

[…]

Real Clear Science

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Source: Nels A. Iverson, Ross Lieb-Lappen, Nelia W. Dunbar, Rachel Obbard, Ellen Kim & Ellyn Golden. The first physical evidence of subglacial volcanism under the West Antarctic Ice Sheet. Scientific Reports 7, Article number: 11457 (2017) doi:10.1038/s41598-017-11515-3

Iverson et al think that the eruptions were fairly small, with possible phreatic eruptions due to basal meltwater.  There is no evidence that the eruptions destabilized the ice sheet; but they almost certainly would have breached the surface of the ice.

Cool stuff… Or hot stuff maybe.  The full paper is available online:

Nels A. Iverson, Ross Lieb-Lappen, Nelia W. Dunbar, Rachel Obbard, Ellen Kim & Ellyn Golden. The first physical evidence of subglacial volcanism under the West Antarctic Ice Sheet. Scientific Reports 7, Article number: 11457 (2017) doi:10.1038/s41598-017-11515-3

A couple of items do seem to merit some ridicule:

The finding left Robert Bingham, one of the study’s authors, with an urgent question.

“The big question is: how active are these volcanoes? That is something we need to determine as quickly as possible,” he told The Guardian.

Why on Earth do we need to determine how active the volcanoes are… “as quickly as possible”?  It’s not like we can do anything to prevent them from erupting.  Of course, he was speaking to The Grauniad.

“Continuing ice loss from WAIS will eventually lower the ice sheet elevation and may cause a positive feedback by increasing volcanism in West Antarctic. Although there is no supporting evidence linking enhanced volcanism with collapse of WAIS in the Quaternary…

 

Melting of the WAIS could increase volcanism under the WAIS causing the WAIS to melt…

The eruptions didn’t occur during an interglacial stage when the WAIS may have been on the thin side.  The eruptions 22,300 and 44,800 years ago during the coldest phase of the last Pleistocene glacial stage, when the WAIS was very likely thicker, colder and less “melty” than it is today.

AntTemp

Antarctica: Pleistocene CO2 and Temperature

 

 

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71 thoughts on “Evidence of Recent Volcanic Eruptions Under the Western Antarctic Ice Sheet

  1. “If one of these volcanoes were to erupt it could further destabilise west Antarctica’s ice sheets. Anything that causes the melting of ice – which an eruption certainly would – is likely to speed up the flow of ice into the sea.”

    It’s more likely to speed up the rate of message migration to some other scare tactic in the political CAGW ecosystem, including Jerry Brown’s talking points. Focusing on one volcanically active corner of a frozen continent was not a good idea to begin with.

    • WIAS has been losing ice despite there being not warning on the continent beyond the isolated penisula, it was argued ( assumed ) that this was due to warmer sea waters undercutting the ice and “melting it from below”.

      The question of the activity record of this chain of volcanoes seems to be utmost importance in understanding the cause of this melting: is it volcanic or AGW ?

      BTW these “new” volcanoes are simply the missing link in the Ring of Fire, which up until now looked like a horseshoe, not a ring.

      • now try to find that part of Antarctica from the peninsula, round Mt Melbourne in the Ross sea on this map:

        Hint the Ross sea is due south of NZ. ;)

      • Why on Earth do we need to determine how active the volcanoes are… “as quickly as possible”? It’s not like we can do anything to prevent them from erupting.

        I would guess he was trying to say “OMG, it may be worse than we thought” and we need to know if sea levels with rise even faster than Al Gore prophesied. ( More money for further study needed urgently ).

        In fact we do need to know urgently because then we can stop wasting money and destroying the economy and put the funds to much more useful projects than fruitlessly “cutting carbon”.

      • Even if it could be proven that the melting of the WAIS was entirely due to volcanic activity… They would still say “OMG, it *is* worse than we thought!!! Since the volcanoes are melting the ice, we need even more grants to study climate change and decarbonize the economy!”

      • Greg, that map for some reason does not include volcanoes in Antarctica. There are several active ones on the Peninsula as well:

        Most of these volcanoes are connected the the active rift in West Antarctica. This is an intra-plate rift (like the Great Rift Valley of Africa), and may mean that the Anterctic Plate is beginning to split.

      • The ‘Ring of Fire’ plate boundary is very evident on Google Earth, and is marked by a chain of islands that are volcanic in origin. It astounds me that this segment of the Ring of Fire is not included on most maps.

      • @ David Middleton
        A pretty depressing observation — mainly because it’s accurate.

        It is very difficult to retain much faith in the integrity of scientists when you realise that they have much the same preoccupation as everyone else, i.e. getting their meal tickets punched.

    • Yeah, Jerry Brown needs more urgency to cement his “Legacy”…. Someone might notice the tombstone he’s attempting to put over the Diablo Canyon NPP, CA’s last source of reliable, carbon-free electricity ;-[

    • No, the other way around. The weight of the ice inhibits eruptions. Data from Iceland shows that eruptions increase significantly as the ice melts.

      • I think probably the icecap is probably just another rock layer from the magma’s point of view. The ice happens to have low melting and boiling points compared to the minerals the molten rock has already worked its way through, but probably that’s about it. I’m guessing that any ice melted by vulcanism probably travels a few tens of km across or through the ice sheet then solidifies like any other lava flow? Most of it doesn’t make it to the ocean unless the volcano is very close to the coast?

  2. When they’re forced to acknowledge some big geologic factors that influence life one earth, they try to fit these factors into their narrative. Without the “ice cap,” the volcanos might introduce a lot of CO2? Are we supposed to cut our CO2 emissions enough to make up for that?

    • With a periodic eruption potential of 22,500 years, (44,800 – 22,500 = 22,300) we could see a potential event in the next 200 years. With a potential sea level rise projection we would have 200 years to create the necessary infrastructure to accommodate the potential coastal impacts.

  3. With Arctic sea ice extent growing for five years now, alarmists need Antarctic land ice to shrink, so will take whatever help they can get from volcanoes.

  4. With the current religious belief in Catastrophic CC being so fervent, the Climate priests are not that far from demanding offerings from taxpayers to appease the Volcano gods.

  5. While interesting, is hardly news. It was reported in Nature in 2008 that volcanic ash had been found in Pine Island Glacier (Amundsen Embayment, WAIS) from a large eruption about 2300 years ago (date based on snow accumulation from a PIG ice core).

    • There are lots of tephra layers in Antarctic ice cores. They are used routinely for dating and correlating ice-cores. Since tephra from different volcanoes are chemically distinct it is sometimes possible to correlate layers from different cores when the eruptions were large ones.
      The TALDICE core for example contains 13 tephra layers from the previous interglaciaton, or rather more than one per millenium.

  6. It is a little appreciated fact (outside of the mining and petroleum industries) that the earth itself is a radiogenic heat source. Current output is estimated at about 20 terawatts. This heat rises to the surface all around the world, albeit tectonically active areas will see more of this heat than placid areas. Glaciers in contact with the earth will also experience this heat, melting where they contact the ground and thermostatically regulating the earth’s surface temperature to 0° C as the ice melts.
    The variable nature of the heat output from tectonically active areas should be obvious to all.
    The more local heat is absorbed by the glacier, the faster the ice melts. This is likely the main source of heat for glacial melting, as it continues 24/7/365. It is the melting of the bottom of the glacier by this geothermal heat that produces a lubricating layer of water and enables glaciers to flow.
    Back in 2007 researchers from Woods Hole Oceanographic Institution discovered active hydrothermal vents on the Gakkel Ridge, including the unconsolidated fragmented pyroclastic volcanic deposits that cover the axial valley of the ridge (whose area is greater than 10 km2). This area under the Arctic Ice Cap (roughly coinciding with the northernmost extent of the Mid-Atlantic ridge) produces enough heat continually to support entire microbial communities based on chemosynthesis rather than photosynthesis. The communities included at least 6 novel microbial species, which attests to their longevity.
    Long time earth-watchers may recall that this was about the time the warmists began to panic about the disappearing Arctic Ice Cap.
    Bottom line: heat from the earth melts all glaciers from the bottom up, where nary a sensor has been installed to demonstrate the fact.

    • “This is likely the main source of heat for glacial melting, as it continues 24/7/365. It is the melting of the bottom of the glacier by this geothermal heat that produces a lubricating layer of water and enables glaciers to flow.”

      However large parts of the Greenland and Antarctic ice is “cold based”, i e frozen to the ground below. Whether the geothermic heat is enough to cause bottom melting is a complex matter, depending on heat flow, thickness of the icecap and the air temperature above the icecap.

    • tadchem, good point. I did a review recently and there appear to be three major issues around heating of the ocean from below through the seafloor:

      1. Is geothermal energy powerful enough to make a difference upon the vast ocean heat capacity?
      2. If so, Is geothermal energy variable enough to create temperature differentials?
      3. Most of the ocean floor is unexplored, so how much can we generalize from the few places we have studied?

      Geologists appear to be more interested in these effects than climatologists.

      https://rclutz.wordpress.com/2016/10/05/overview-seafloor-eruptions-and-ocean-warming/

      • “1. Is geothermal energy powerful enough to make a difference upon the vast ocean heat capacity?”

        Not on the whole ocean. The flow is on the order of 0.1 Wm^-2. However it might be enough to influence the thermohaline circulation in the deep ocean which has a circulation time of 1,000 years or more. Over such a long time the bottom water should be warmed slightly even by such a small heat flow.

      • tty

        With the vast majority of the ocean floor unexplored to date, we have no idea what the geothermal flow rate into the oceans is. It’s never been measured!

        Global “estimates” are at least 1 million submarine volcanos, and no idea how many are active. Add in geothermal vent fields that pump boiling water into the oceans 24/7 and you’ve got a lot of heat.

        http://volcano.oregonstate.edu/submarine

        And deep ocean pressure does not stop submarine volcanos from erupting violently as previously assumed.

      • Actually there have been quite a lot of heat flow measurements made, both in shallow and in deep drilling especially within the DSDP and ODP projects. Among other things it has been found that heat flow correlates quite well with the age of the ocean floor. The measurements are reasonably well distributed globally (though there are very few in the Arctic ocean for obvious reasons.
        Of course some hotspots may have been missed, but the resultsa are certainly not orders of magnitude wrong.

    • Tadchem: If “heat from the earth melts all glaciers from the bottom up, where nary a sensor has been installed to demonstrate the fact” they why wouldn’t it melt the permafrost? Surely the fact that across vast swaths of the northern hemisphere the ground is permanently frozen would suggest that the earth’s heat flow is almost never strong enough to melt anything except in isolated areas (e.g. hot springs, thermal vents)

      • “The variable nature of the heat output from tectonically active areas should be obvious to all.” – Tadchem (above at 11:58 am; September 14).

    • tadchem September 14, 2017 at 11:58 am
      It is a little appreciated fact (outside of the mining and petroleum industries) that the earth itself is a radiogenic heat source. Current output is estimated at about 20 terawatts. This heat rises to the surface all around the world, albeit tectonically active areas will see more of this heat than placid areas. Glaciers in contact with the earth will also experience this heat, melting where they contact the ground and thermostatically regulating the earth’s surface temperature to 0° C as the ice melts.
      —————————————–

      Very good comment thank you.

      Very few people knew about that volcanic eruption up on Gakkel Ridge. It was estimated to be of the same magnitude as Vesuvius. Scientists themselves didn’t believe that volcanic eruptions were possible under the ocean. For Gakkel Ridge a robot was designed to study and gather info. More studies have been ongoing in other locations under the oceans on this subject.

  7. “Although there is no supporting evidence linking enhanced volcanism with collapse of WAIS in the Quaternary…”

    Which might possibly be due to the fact that there is essentially no supporting evidence for collapse of the WAIS in the Quaternary either.

  8. By the way if they can identify the volcanoes that caused these tephra deposits it would be easy to find out if they breached the ice-cap during the eruption or not (many volcanoes don’t, the eruptions take place in a large waterfilled cavity in the ice). Volcanoes who do break through have a very charcteristic shape, for example Herdhubreidh in Iceland:

  9. Terrific post and contributions. Geology and Earth history should be compulsory school subjects.

  10. Yet another graph showing that CO2 lags temperature. If the physics of LWIR backradiation are immediate, why the hundreds of years lag time?

    • Henry’s law of physical chemistry. Cold water holds more dissolved gas than warm water. As ovean surface warms, it outgasses dissolved CO2. Temp/CO2 lag is ~800 years, corresponding to the period of the thermohaline circulation.

  11. Maybe this is a little off-topic, but the graph at the bottom of the post shows a green line which represents CO2 concentration in Antarctic ice cores, which bounces around from 200 to 280 ppm through most of the last 800,000 years, then suddenly spikes to 388 ppm in AD 2010.

    But was 388 ppm actually recorded in a recent Antarctic ice core, or was this a recent Mauna Loa reading thrown in at the present (or near past)? We don’t have readings at Mauna Loa before about 1970, but have the CO2 concentrations in recent Antarctic ice cores shown a sudden spike upward in the 20th century?

    The point is, is the concentration of CO2 from Antarctic ice cores representative of simultaneous CO2 concentrations over the rest of the globe? CO2 in Antarctic ice cores probably resulted from CO2 dissolving in raindrops in clouds which likely formed at least 65 degrees South Latitude, then fell as snow on Antarctica. In the absence of man-made CO2 emissions in the distant past, most CO2 in the atmosphere either came from outgassing from the oceans or from respiration of animals, and could be consumed by plant photosynthesis.

    There is not much plant or animal life within a snowflake’s horizontal travel distance during its fall from a cloud onto Antarctica, but CO2 concentrations in the tropics and temperate regions (where most of the landmass is in the Northern Hemisphere) could be much higher than in Antarctica at the same time, due to animal respiration and outgassing of CO2 from warmer oceans.

    Mauna Loa is on a relatively small island in the tropics, with low human CO2 emissions nearby, but it is surrounded by thousands of miles of warm oceans, unlike Antarctica, which is mostly frozen over and surrounded by cold oceans. It is reasonable to believe that CO2 concentrations at Mauna Loa (or elsewhere in the tropics) are higher, and were higher in the past, than contemporaneous CO2 concentrations in Antarctic ice.

    • “CO2 in Antarctic ice cores probably resulted from CO2 dissolving in raindrops in clouds which likely formed at least 65 degrees South Latitude, then fell as snow on Antarctica.”

      No it comes from air enclosed in bubbles when the snow solidifies to ice. And snow solidifies from water vapor, not raindrops. The latter gives hail or graupel, neither of which occurs under the weather conditions in Antarctica. Ever looked closely at a snowflake? Does it look like a frozen raindrop?

    • 388 ppm was the MLO value when I assembled that graph (2010).

      There are firn, flask and atmospheric measurements from Antarctica which match the MLO instrumental data. The highest concentrations actually recorded in Antarctic ice cores are from the Law Dome DE08 core (~320 ppm IIRC). Of course, ice cores will always yield a lower value than atmospheric measurements due to the lag between snowfall and ice formation.

  12. We have to sort this out “as quickly as possible” because every additional dollar of research grant money is of “vital importance”. If they wait too long, Robert Bingham might already be retired and unable to benefit from that cash. So his sense of urgency here might mean he is contemplating retirement sometime within the next 10 years and wants the cash now.

  13. As a geologist, I would love to have been a reviewer on this paper and taken the red pen to the Abstract as follows. Separating the geology from the warmist group-think.

    Abstract

    The West Antarctic ice sheet (WAIS) is highly vulnerable to collapsing because of increased ocean and surface temperatures. New evidence from ice core tephra shows that subglacial volcanism may can breach the surface of the ice sheet and may pose a great threat to the West Antarctic Ice Sheet (WAIS) stability. Micro-CT analyses on englacial ice core tephra along with detailed shard morphology characterization and geochemical analysis suggest that two tephra layers were derived from subglacial to emergent volcanism that erupted through the WAIS. These tephra were erupted though the center of the ice sheet, deposited near WAIS Divide and preserved in the WDC06A ice core. The sources of these tephra layers were likely to be nearby subglacial volcanoes, Mt. Resnik, Mt. Thiel, and/or Mt. Casertz. A widespread increase in ice loss from WAIS could trigger positive feedback by decreasing ice mass and increasing decompression melting under the WAIS, increasing volcanism. Both tephra were erupted during the last glacial period and a widespread increase in subglacial volcanism in the future could have an considerable effect on the stability of the WAIS and resulting sea level rise.

  14. I knew about volcanoes and geothermal activity in antarctica but I was surprised to hear biologists talking about caves under the ice where temps of 20C are regularly encountered. Providing a haven for remnant life, including land mammals (though I dont believe they actually found any alive in the current study). But it shows how tenous many apparently straightforward assumptions actually are.

  15. Love the idea of more or less “melty” ice is this a relative of the “rotten” ice up north?

    James Bull

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