[heat source] Plays critical role in movement, melting
Via Eurekalert KINGSTON, R.I. — June 22, 2018 — A researcher from the University of Rhode Island’s Graduate School of Oceanography and five other scientists have discovered an active volcanic heat source beneath the Pine Island Glacier in Antarctica.
The discovery and other findings, which are critical to understanding the stability of the West Antarctic Ice Sheet, of which the Pine Island Glacier is a part, are published in the paper, “Evidence of an active volcanic heat source beneath the Pine Island Glacier,” in the latest edition of Nature Communications.
Assistant Professor Brice Loose of Newport, a chemical oceanographer at GSO and the lead author, said the paper is based on research conducted during a major expedition in 2014 to Antarctica led by scientists from the United Kingdom. They worked aboard an icebreaker, the RRS James Clark Ross, from January to March, Antarctica’s summer.
“We were looking to better understand the role of the ocean in melting the ice shelf,” Loose said. “I was sampling the water for five different noble gases, including helium and xenon. I use these noble gases to trace ice melt as well as heat transport. Helium-3, the gas that indicates volcanism, is one of the suite of gases that we obtain from this tracing method.
“We weren’t looking for volcanism, we were using these gases to trace other actions,” he said. “When we first started seeing high concentrations of helium-3, we thought we had a cluster of bad or suspicious data.”
The West Antarctic Ice Sheet lies atop a major volcanic rift system, but there had been no evidence of current magmatic activity, the URI scientist said. The last such activity was 2,200 years ago, Loose said. And while volcanic heat can be traced to dormant volcanoes, what the scientists found at Pine Island was new.
In the paper, Loose said that the volcanic rift system makes it difficult to measure heat flow to the West Antarctic Ice Sheet. “You can’t directly measure normal indicators of volcanism — heat and smoke — because the volcanic rift is below many kilometers of ice,” Loose said
But as the team conducted its research, it found high quantities of an isotope of helium, which comes almost exclusively from mantle, Loose said.
“When you find helium-3, it’s like a fingerprint for volcanism. We found that it is relatively abundant in the seawater at the Pine Island shelf.
“The volcanic heat sources were found beneath the fastest moving and the fastest melting glacier in Antarctica, the Pine Island Glacier,” Loose said. “It is losing mass the fastest.”
He said the amount of ice sliding into the ocean is measured in gigatons. A gigaton equals 1 billion metric tons.
However, Loose cautions, this does not imply that volcanism is the major source of mass loss from Pine Island. On the contrary, “there are several decades of research documenting the heat from ocean currents is destabilizing Pine Island Glacier, which in turn appears to be related to a change in the climatological winds around Antarctica,” Loose said. Instead, this evidence of volcanism is a new factor to consider when monitoring the stability of the ice sheet.
The scientists report in the paper that “helium isotope and noble gas measurements provide geochemical evidence of sub-glacial meltwater production that is subsequently transported to the cavity of the Pine Island Ice Shelf.” They say that heat energy released by the volcanoes and hydrothermal vents suggests that the heat source beneath Pine Island is about 25 times greater than the bulk of heat flux from an individual dormant volcano.
Professor Karen Heywood, from the University of East Anglia in Norwich, the United Kingdom, and chief scientist for the expedition, said: “The discovery of volcanoes beneath the Antarctic ice sheet means that there is an additional source of heat to melt the ice, lubricate its passage toward the sea, and add to the melting from warm ocean waters. It will be important to include this in our efforts to estimate whether the Antarctic ice sheet might become unstable and further increase sea level rise.”
Does that mean that global climate change is not a factor in the stability of the Pine Island Glacier?
No, said Loose. “Climate change is causing the bulk of glacial melt that we observe, and this newly discovered source of heat is having an as-yet undetermined effect, because we do not know how this heat is distributed beneath the ice sheet.”
He said other studies have shown that melting caused by climate change is reducing the size and weight of the glacier, which reduces the pressure on the mantle, allowing greater heat from the volcanic source to escape and then warm the ocean water.
“Predicting the rate of sea level rise is going to be a key role for science over the next 100 years, and we are doing that. We are monitoring and modeling these glaciers,” Loose said.
The scientists conclude by writing: “The magnitude and the variations in the rate of the volcanic heat supplied to the Pine Island Glacier, either by internal magma migration, or by an increase in volcanism as a consequence of ice sheet thinning, may impact the future dynamics of the Pine Island Glacier, during the contemporary period of climate-driven glacial retreat.”
In addition to Heywood, Loose worked with Alberto C. Naveira Garabato, of the National Oceanography Centre at the University of Southampton, United Kingdom; Peter Schlosser of Arizona State University’s School of Earth and Space Exploration and the Lamont-Doherty Earth Observatory at Columbia University; William Jenkins of the Woods Hole Oceanographic Institution in Massachusetts; and David Vaughn of the British Antarctic Survey, Cambridge, United Kingdom.
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The paper (open access): https://www.nature.com/articles/s41467-018-04421-3
Evidence of an active volcanic heat source beneath the Pine Island Glacier
Abstract
Tectonic landforms reveal that the West Antarctic Ice Sheet (WAIS) lies atop a major volcanic rift system. However, identifying subglacial volcanism is challenging. Here we show geochemical evidence of a volcanic heat source upstream of the fast-melting Pine Island Ice Shelf, documented by seawater helium isotope ratios at the front of the Ice Shelf cavity. The localization of mantle helium to glacial meltwater reveals that volcanic heat induces melt beneath the grounded glacier and feeds the subglacial hydrological network crossing the grounding line. The observed transport of mantle helium out of the Ice Shelf cavity indicates that volcanic heat is supplied to the grounded glacier at a rate of ~ 2500 ± 1700 MW, which is ca. half as large as the active Grimsvötn volcano on Iceland. Our finding of a substantial volcanic heat source beneath a major WAIS glacier highlights the need to understand subglacial volcanism, its hydrologic interaction with the marine margins, and its potential role in the future stability of the WAIS.
OK, but if we we spend a stack of national debt growth on useless wind farms, these volcano things will just go away, right?
“Climate change is causing the bulk of glacial melt that we observe …………” states Brice Loose, with an expert’s certainty.
Why can’t today’s scientists come out honestly and say, “Oops – these new findings certainly do change our confidence in the correctness of the theories which we have had until now”. ??? They would actually sound more convincing as scientists by saying that.
They would kiss their funding and career good bye. This global warming hoax is affecting all science.
Because that wouldn’t be honest. The impact of this volcano on Antarctica melt rates is tiny.
Prove it. The author of the study didn’t even try to.
Calculations provided below 2 days ago.
No Chris, Nick’s calculations are a deflection and don’t address the actual mechanism for the glacier flow speeding up. I do love how climate alarmists will jump on anything, even pure nonsense, to maintain their “beliefs”. It is obvious your entire viewpoint is “faith” based.
“Climate change is causing the bulk of glacial melt that we observe, and this newly discovered source of heat is having an as-yet undetermined effect, because we do not know how this heat is distributed beneath the ice sheet.”
Really? You don’t know what effect the volcano under the ice sheet is, but you’re 100% certain that it’s coming from climate change. Seems you first need to quantify the melt from that under-ice source before you can make any proclamation about the source of the bulk of melt…
“However, Loose cautions, this does not imply that volcanism is the major source of mass loss from Pine Island. On the contrary, “there are several decades of research documenting the heat from ocean currents is destabilizing Pine Island Glacier, which in turn appears to be related to a change in the climatological winds around Antarctica,” Loose said”
Re, Ocean temps : ARGO data of circum-Antarctic waters shows no trend since 2004 and the 30 year T trend of the Southern Ocean is negative.
As for air temps, they speak for themselves … -60C etc with no trend over the entire record.
Source: https://climatism.blog/2018/05/10/bias-by-omission-no-mention-of-mother-natures-undersea-volcanoes-in-the-latest-antarctic-global-warming-scare-story/
“… this doesn’t imply that volcanism is the major source of ice loss… climate change blah blah.” The article repeats this three times in the classic nursery rhyme style. How about this bit of logic:
“Climate change is causing the bulk of glacial melt that we observe, and this newly discovered source of heat is having an as-yet undetermined effect, because we do not know how this heat is distributed beneath the ice sheet.”
But they know how clinate change is distributed beneath the ice sheet!
This “major discovery” was predated back in 2008! Ha ha! “Tail Wagging The Dog”!
https://www.livescience.com/2242-buried-volcano-discovered-antarctica.html
https://www.nature.com/news/2008/080118/full/news.2008.304.html
I am puzzled by this “discovery”, I’ve known about the Pine Island volcano for years, and I’m not even a volcanologist or glaciologist… It’s news again because someone managed to get a grant
Nick Stokes provided a calculation of how many tons of ice/sec 2500 MW would melt:
Heat H=2.5e+9 J/sec; LH ice 3.34e+5 J/kg
H/LH = 2500/0.33 = 7500 kg/s = 7.5 tons/s.
Even if we take the high end of the estimate, which is 2500+1700 = 4200, that would give a melt rate of 12.6 tons/sec. Converting to annual ice melt gives a rate of 400M tons/yr.
Last year the WAIS lost 159B tons. So the Pine Island volcano was responsible for 400M/159B = .25% of WAIS ice loss last year. Not exactly a prime suspect in the tripling of WAIS ice melt rates over the last 6 years.
Heat flow is high to very high almost everywhere under the WAIS:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078843/
http://advances.sciencemag.org/content/1/6/e1500093.full
and references therein.
Putting the average heat flow very conservatively at 100 mW per square meter this means that the total amount of melting under the WAIS would be about 2×10^13 kg/year or about 20B tons. Of course less than calving but far from negligible and definitely very important for ice flow and glacier dynamics. And then there is frictional heating too.
Can you show your calculations?
Area of WAIS: 2,2×10^6 km^2 = 2.2×10^12 m^2
Heat flow: 100 mWm^-2 = 0.1 J
Heat of fusion for water at 273 K = 334 Jg^-1
One billion tons = 10^15 g = 10^12 kg
Length of year 365.25×86,400 = 31,557,600 s
3.16×10^7 x 0.1 x 2.2×10^12/334 x 10^15 = 0.7×10^19/0.3×10^18 = c. 20
Or a bit more quickly as I actually did it: 100 mW is enought to melt a little bit more than one gram of water per hour, which makes a water layer about 9 mm thick after a year (a little less than 9000 hours in a year, 1 mm water weighs one kilogram per square meter)
I read the first paper, it’s about the Thwaites Glacier. That glacier has an area of 1.7×10^5. It seems you applied the measurements for Thwaites to the entire WAIS. The actual figure should be 1.7/22 x 20 = 1.55 Gtons/year, or 1% of what WAIS is losing each year. Correct?
Incorrect. The 100 mWm-^2 average value for West Antarctica was taken from:
J. H. Davies, D. R. Davies 2010, Earth’s surface heat flux. Solid Earth 1, 5–24 (https://www.solid-earth.net/1/5/2010/se-1-5-2010.pdf)
Since that paper was written a large number of further subglacial volcanic centers have been discovered, which is why I said it is a very conservative figure.
By the way read the second paper I linked earlier as well and the paper above. You will learn a bit more about antarctic volcanoes and geology, which you need. Badly.
No, it’s actually you that badly needs to learn more. The vast majority of ice in Antarctica is land based. So land temperatures are what matters, not ocean water temperatures. The mean land temperature on Antarctica is -25C. Far, far below freezing. So it is not valid to take the 100mW/m2, convert it to total heat across all of Antarctica, and then calculate melt rates assuming all the heat is concentrated into a small area. An analogy would be walking into a deep freezer which is at -25, and turning on a hair dryer. You might drop the temperature to -24, or -23, but it is certainly NOT going to thaw the items stored there. Not even a little bit.
http://www-das.uwyo.edu/~geerts/cwx/notes/chap03/antarctica.html
Also, unless you can show that the earth’s heat flux near Antarctica has gone up dramatically since 2012, it would not explain the tripling in Antarctica ice loss since then.
The heat flow was an average for West Antarctica and the calculation was for West Antarctica, nothing else. Heat flow in East Antarctica is almost unknown, but likely to be much lower given the geology.
Surface melting is slight in Antarctica as you say, though not zero since sublimation can be significant as shown by the presence of blueice areas.
So, the mass balance is dominated by calving, which is strongly affected by bed conditions, e. g. the amount of bottom melting.
Whether the local heat flow in the Amundsen Bay area has increased recently is unknown. Heat flow can fluctuate locally, even on short timescales. For example you may have noticed an increase on Hawai’i recently that has attracted a certain amount of publicity.
Sure, but the heat flow in Hawaii is not affecting an area of 2.2×10^6. Let’s say it’s affecting an area 20 km long and 10km out to sea. That’s 200km2, or 1/10,000 of the area of WAIS. For the heat to have increased enough to triple the ice melt rate in WAIS seems highly, highly unlikely to me.
The overall point I am making is that anytime another contributor to warming is pointed out, the reaction here on WUWT is “see, this proves the CAGW is rubbish, the temperature/melting is caused by xx!” Even when, such as in this case, the melting caused by the volcanic heat flow is tiny compared to the total melt rate (.25%, to be exact).
Can you show your calculations?
They are at the top of this indented subthread.
Chris, as has already been pointed out above, your logic is completely flawed. All of the energy to melt the ice does not need to come from the geothermal source. All it has to do is reduce the grounding toe and allow the glacier to speed up.
As the glacier speeds up then it is ocean water (and heat energy) that leads to the melting. This energy is continually replenished by the normal currents.
It is this increased flow that has been observed.
So your argument is that there is no heat-flow except for this one volcano? Seems a bit unlikely.
“heat from ocean currents is destabilizing Pine Island Glacier” Yeah, heat from other volcanoes drifts down in ocean currents. The entire west coast of antarctica sits on the Pacific Ring of Fire. There are volcanoes all along it, from deception island in the north, where it is so warm the sea is 30`C right to the south.
It is interesting to read the paper (in Nature) that reported the first discovery of a active volcano under the WAIS (Mount Casertz) back in 1993. At that time CAGW orthodoxy was not yet fully established, and consequently it says in the final paragraph:
“Therefore the character of the lithosphere within the central West Antarctic rift system and, specifically, the distribution of elevated heat flow and sedimentary basins, represents a fixed boundary condition for the WAIS that is independent of global climate yet could be responsible for triggering the collapse of the ice sheet”
https://www.researchgate.net/publication/232773729_Active_volcanism_beneath_the_West_Antarctic_ice_sheet_and_implications_for_ice-sheet_stability
But now, when the number of known subglacial volcanoes have grown to more than a hundred, this is no longer so.
“this is no longer so”
Really? How is it sifferent from
“The discovery of volcanoes beneath the Antarctic ice sheet means that there is an additional source of heat to melt the ice, lubricate its passage toward the sea, and add to the melting from warm ocean waters. It will be important to include this in our efforts to estimate whether the Antarctic ice sheet might become unstable and further increase sea level rise.”
Where is the “independent of global climate” part in your quotation?
“additional source of heat”. There is no indication that source depends on global climate. That is why they say it is additional.
well thats scientific
find a volcanic source and still deny any melting is from it
has to be the hot oceans n co2
facepalm
That’s not what they said. Did you read the paper? “The localization of mantle helium to glacial meltwater reveals that volcanic heat induces melt beneath the grounded glacier and feeds the subglacial hydrological network crossing the grounding line. “
First, nobody is denying that the volcano would cause some warming. Some comments suggest (and others outright state) that the warming is denied, but obviously that is not true.
Second, when a scientist explains that the volcano is a factor, why jump to your own gut conclusion that it is the primary source of melt? Just because they cannot measure it precisely does not mean that the magnitudes are unknown.
This would be like someone pointing out that a long jump was aided by wind, and having people pile-on and describe how the wind was the reason for most of the distance. Just because you don’t know the exact forcing does not mean the magnitudes are unknown.
“The” Volcano? There is at least a dozen known volcanoes within the Pine Island Glacier drainage basin:
http://sp.lyellcollection.org/content/specpubgsl/early/2017/05/26/SP461.7.full.pdf
Wouldn’t this be more like saying that the long jump was aided by wind (volcanism) and we found the earth was spinning in his favor (climate) ??? I know-not a perfect analogy, but whatever.
Seems a pretty easy computation to show precisely, and to the limits of our ability to measure, what “assistance” the wind would give and any impact from spin to determine the actual jump.
Or, we could use what we think we know of the spinning earth and completely ignore the wind since, to reiterate ad nauseum, “this newly discovered source of heat (wind) is having an as-yet undetermined effect”…..
I believe that you chose a long jump analogy as some sort of subconscious slip, no?
Leap of logic indeed.
Alley, I have to say it is hilarious watching the climate cult try and defend the silly claim that it is “climate change” having the biggest effect on glacial melting even though there is not one iota of evidence there are any warm currents in this area produced by “climate change”. Do you also believe in fairies?
“However, Loose cautions, this does not imply that volcanism is the major source of mass loss from Pine Island.”
And let me caution you to just stick to finding data and following the truth where it leads.
“We weren’t looking for volcanism” is classic. Better turn off the helium-3 sampler next time lest you make more inconvenient, unapproved discoveries in the most volcanically active part of that ice continent.
When you feel heat in the Antarctic – Think volcanoes – Not CO2
As has been the case for millenia?
Much more likely than not.
Also check out photos of snow-laden volcanoes … they sure do melt it (sarc)
Indeed they do….
That looks like a picture from Iceland of the 1995 ‘Jökulhlaup’ that resulted from a well-publicised subglacial eruption which saw the Grímsvötn volcano rapidly melt a large portion of the Vatnajökull glacier. Peak flow rate was estimated at 50,000 cubic metres per second.