Latest Antarctica Volcano Count — 138!
Another Threat to Sea Level Rise
© 2017 by Linda Moulton Howe
“We were amazed. We had not expected to find anything like 91 more volcanoes a mile
down in the ice! ...West Antarctic rift is the densest region of volcanoes in the world.”
- Robert Bingham, Ph.D., Glaciology, Univ. of Edinburgh, Scotland
What is troubling scientists is the ability for these many Antarctic volcanoes,
if they erupted, to cause wide scale melting and breakup of
Antarctica's ice sheets. Image by NASA.
September 29, 2017 Edinburgh, Scotland - Scientists from the University of Edinburgh in Scotland have done the first study of the West Antarctic Rift with ice-penetrating radar and have found what might be the largest volcanic region on Earth, larger than the East Africa volcanic ridge that contains Mt. Kilimanjaro. They analyzed the shape of the land beneath the ice using measurements from ice-penetrating radar, and compared the findings with satellite and database records, as well as geological information from aerial surveys.
To their surprise, they now have a count of 138 volcanoes that range in height from 320 feet (100 m) to 12,600 feet (3,850 m). The peaks are concentrated in a region known as the West Antarctic Rift System, spanning 2,174 miles (3,500 km) from Antarctica's Ross Ice Shelf to the Antarctic Peninsula. Some of the peaks stick out of the mile thick ice, while most are below the ice sheet.
The melt rate of West Antarctica's Thwaites Glacier is currently responsible for about
1% of global sea level rise. Thwaites Glacier covers an area nearly as large as the state
of Washington (70,000 square miles, or 182,000 square kilometers). Satellite measurements
show that its rate of ice loss has doubled since the 1990s. The glacier has the potential
to add several inches to global sea levels. Aerial image by NASA/James Yungel.
In one of the glaciers known as Thwaits Glacier, there has been a large volume of disappearing ice that might be because a subglacial volcano there is melting the ice and causing water runoff hidden from the surface. The melt rate of West Antarctica's Thwaites Glacier is currently responsible for about 1% of global sea level rise. Thwaites Glacier covers an area nearly as large as the state of Washington (70,000 square miles, or 182,000 square kilometers). Satellite measurements show that its rate of ice loss has doubled since the 1990s. The glacier has the potential to add several inches to global sea levels. Could the glacier's melt be related to any one of the 138 volcanoes becoming warm and active under the Antarctic glacier. And what happens if several of those West Antarctic Rift volcanoes became active and ice melt really accelerated?
That's a question that one of the world's top glaciologists would like to answer. He is Robert Bingham, Ph.D., Chancellor's Fellow, Glaciology and Geophysics, University of Edinburgh, Scotland. Prof. Bingham was awarded the Polar Medal by H. M. the Queen in 2013 for contributions to Arctic and Antarctic science.
Robert Bingham, Ph.D., Chancellor's Fellow, Glaciology
and Geophysics, University of Edinburgh, Scotland. Awarded
the Polar Medal by H. M. the Queen in 2013 for contributions
to Arctic and Antarctic science. Image by Univ. of Edinburgh.
Robert Bingham, Ph.D., Chancellor's Fellow, Glaciology and Geophysics, University of Edinburgh, Scotland: “We were amazed to find that there were as many as 91 new volcanoes beneath the West Antarctic Ice Sheet. The known volcanoes, the 47 that we already recorded in Antarctica, these are all volcanoes that stick out above the ice surface. And prior to this study, it was a great surprise to us to find that were 91 volcanic shapes below the ice surface that hadn't been recorded before. And these are volcanoes that we now need to be investigating in more detail to see whether they're active or dormant.
YEAH. HOW MANY COULD BE ACTIVE, AND IF THEY ARE, WHAT WOULD THE CONSEQUENCES BE?
Absolutely. I think we've got to be suspicious that quite a few of them are active. I think the main thing that we all need to be aware of is that the biggest influence on Antarctic ice loss is unquestionably the warming climate around Antarctica. Even if these volcanoes were generally active, the main cause of the ice loss is still climate warming. That said, if we actually do discover that a significant number of the volcanoes are active, that could accelerate the ice loss that we're seeing already.
WHAT IF ONE OR MORE OF THESE UNDER ICE VOLCANOES STARTED ERUPTING? YOU WOULD HAVE ICE MELTING DEEP DOWN.
Yes. There's an awful lot we still don't know about how these processes work. And the fundamental reason for that is it's very, very difficult to see at the bed of mile-thick ice. Probably our best knowledge of how volcanoes and ice caps interact comes from Iceland where we do see eruptions beneath the ice. And the consequences there tend to be the emergence of floods from around the ice caps. In Antarctica, it may happen already because the ice flows all the way to the ocean, and if subglacial floods do occur, they probably escape directly into the ocean unobserved. So it's not so much the meltwater that's released by the eruption itself, it's the effect it might have on speeding up the ice flow in any location in Antarctica. And that's something that we really don't know very well at all.
BUT WHY IS THAT IMPORTANT?
Well, whenever you see a lot of water access the bed, and the faster the ice flows, the quicker it's going to lower elevations, in the case of Antarctica, meeting the ocean. And the quicker it's removed ultimately determines sea level rise. So the processes we're talking about here are slight accelerations of what we're seeing already, mostly induced by climate warming.
ISN'T IT POSSIBLE THAT IF YOU ACCELERATE THE MELTING THAT WE'VE GOT SOME KIND OF DOMINOES FALLING EFFECT HERE, AND MORE AND MORE WEST ANTARCTIC ICE IS MELTING, IT IS RELEASING PRESSURE ON THAT LAND, THE BED, WHERE THE VOLCANOES ARE, AND ISN'T THERE A QUESTION ABOUT AS PRESSURE IS RELEASED THAT MORE VOLCANISM COULD BE PROVOKED IN THESE VOLCANOES BY THE FACT THAT THE ICE IS MELTING AND THE PRESSURE IS RELEASING?
Yes. That is a definite prospect, and we say that based on what we've seen in Iceland and Alaska. So these are two parts of the world where there's active volcanism and ice has been removed from those locations over the last several thousand years. Iceland today has less ice than it has done for hundreds, if not thousands, of years. And there's been an association as the ice pressure has reduced on the ground below, there's actually been an increase in the frequency of volcanism. So I think there's every reason to suspect that if the West Antarctic Ice Sheet continues to thin as we've been seeing for the last 40-50 years ever since we've been watching it with satellites, as the ice is thinning, the pressure on this volcanic bed will be reducing, and it will actually allow increased volcanism. Presumably that can only be a bad thing for heating and accelerated ice loss down the line.
BECAUSE THAT MEANS IT'S ACTUALLY ADDING TO SEA LEVEL RISE BECAUSE THAT IS WATER THAT IS ON LAND THAT WOULD BE MELTING AND RUNNING OFF EVEN MORE RAPIDLY INTO THE OCEAN.
Yeah, that's right. Any of the ice that's currently trapped in Antarctica, and we could say the same about Greenland, any of the ice that melts and becomes water is ultimately converted into sea level rise. When you look back through the Earth's history and whenever there's been less ice in Antarctica and Greenland in particular because they hold by far the most ice, sea levels have been several meters higher around the world.
Will We See Any of the 138 Subglacial West
Antarctic Volcanoes Erupt Through Ice?
WE MIGHT, IN THIS CENTURY, SEE VOLCANOES ERUPTING THROUGH ANTARCTIC ICE SOMEWHERE, JUST LIKE WE HAVE SEEN IN THE LAST COUPLE OF YEARS OF VOLCANOES THAT HAVE BEEN BLASTING OFF IN THE ICY PARTS OF FINLAND AND THAT PART OF EUROPE?
Well, that's a really good question. It would have to happen in the right place, by which I mean that the ice would have to be sufficiently thin to achieve the effect at the ice surface. It's much more likely, I think, that there have been eruptions and we haven't detected them because we haven't actually had the equipment there to feel it, vibrations for example. You've got to remember that there's still a mile of ice on top of these, so the effects are kind of unseen.
YOU NOW KNOW THAT THERE 138 VOLCANOES UNDERNEATH THE ICE OF WEST ANTARCTICA, AND THAT THE IMPLICATION IS THAT AT LEAST SOME OF THOSE 138 VOLCANOES ARE GOING OFF AT SOME POINT AND MELTING ICE, EVEN IF IT IS A MILE OR SO DOWN, THAT INVISIBLE VOLCANOES ARE HAVING IMPACT ON MELTING WATER THAT'S RUNNING OFF INTO THE OCEANS WHICH IS CONTRIBUTING TO SEA LEVEL RISE, BUT THAT THERE IS A DISTINCT POSSIBILITY THAT WHERE THE ICE COULD THIN SO MUCH IN WEST ANTARCTICA, THAT WE ACTUALLY COULD SEE ONE OF THESE VOLCANOES START ERUPTING OUT OF THAT ANTARTIC ICE.
That's right, yeah. There's an intriguing story, actually, from many years ago, actually, when I first got involved in Antarctic research. It's possible that someone did see an eruption down there, and there's a photograph of it somewhere in West Antarctica from one of the early expeditions. And we're talking probably the 1960s. And there's a photograph of what could be an eruption, but could also be effectively a cloud. And no one's ever really been sure. But it was certainly in the right place. It was near some of the known volcanoes. But it was never completely verified. The chances are that at some point we will see one. People in the community suspect that there are active volcanoes beneath the ice. It's often said that we know less about the bed of Antarctica than we do about the surface of the moon and Mars. I think that very much holds true today.
IT'S AN ODD FEELING TO CONTEMPLATE THAT THERE ARE 138 VOLCANOES IN WEST ANTARCTICA UNDER ABOUT A MILE OF ICE, AND THAT THEY'VE BEEN GOING OFF, APPARENTLY, WHEN WE DIDN'T KNOW IT. THE CONSEQUENCES ARE LIKE SOMETHING INVISIBLE BUT HAVING A POTENTIAL GREAT IMPACT ON OUR PLANET IN THE FUTURE.
That's absolutely right. It's amazing how much there still is to discover on the planet. And the other thing that I draw from it is something like global sea level rise is quite an insidious kind of effect; it's quite slow. And most people don't really notice this sort of thing going on in their lifetimes. The public needs to be aware that these processes are happening.
Was West Antarctica's Rift of Volcanoes
Once Part of East Africa's Volcanoes in Gondwanaland?
ISN'T IT TRUE THAT UP UNTIL NOW AND YOUR DISCOVERIES IN WEST ANTARCTICA THAT THE DENSEST REGIONS OF VOLCANOES IN THE WORLD WERE IN EAST AFRICA, AND ONE OF THEM THAT EVERYBODY HAS HEARD ABOUT IS MOUNT KILIMANJARO? WHY WOULD THERE BE THIS DENSE REGION OF VOLCANOES IN EAST AFRICA AND IN THE WEST ANTARCTIC?
a) Location of the main components of the West Antarctic Rift System and confirmed volcanoes
(red circles). b) Location of Holocene volcanoes (red circles) in the Ethiopia/Kenya
branch of the East African Rift (shaded area).
If you back several hundreds of thousands of years, Africa and Antarctica were actually pretty close to each other once, and in fact, they were once joined. So I guess it's kind of quite amazing now that Africa sits over the equator and Antarctic is over the pole. And actually, we do find some of these volcanic domes we've discovered in Antarctica are pretty similar dimensions to Kilimanjaro.
SO YOU'RE TALKING ABOUT THE TIME OF GONDWANALAND WHEN ALL THE LANDMASSES WERE TOGETHER AND THEY BEGAN TO SEPARATE, THAT ANTARCTICA AND AFRICA WERE ONE LANDMASS AND THAT THAT IS WHERE VOLCANOES WERE CENTERED ON THIS PLANET IN A REGION WHERE ANTARCTICA AND AFRICA WERE TOGETHER.
Antarctica land mass in the bottom as it's breaking away from southeastern African continent
where there might have been one big volcanic ridge 200 million years ago before
Gondwanaland kept spreading apart. Maybe 138 of those original Gondwanaland
volcanoes ended up in Antarctica at the South Pole.
You're absolutely right. They were all once part of Gondwana. And the volcanism that you see in these places, it always occurs where these landmasses start to separate. Whether the volcanism comes first or is the result of the separating land masses, I guess that's not totally known. But the volcanism is associated with these landmasses breaking apart. And you see it in Africa today because the landmass is actually slowly breaking apart, some of it moving toward the Atlantic, some of it moving toward the Indian Ocean. And these great volcanoes that you see like Kilimanjaro and Mount Kenya, they're all a result of what's called the East African Rift slowly opening. What we think we're seeing in Antarctica now is a similar process. The Western Antarctic is overlying a rift. We've thought it was a similar scale to East Africa, but I think we're now starting to appreciate that it's an even bigger system than East Africa.
WHAT DO SCIENTISTS THINK IS THE LAST TIME THAT ANTARCTICA HAD NO ICE ON IT?
East Antarctica, probably about 34 million years ago. The ice sheet sits on a large continent, and we think that probably about 15-20 million years ago, that was when ice first spread over what is now West Antarctica.
A hundred million years ago, it was pretty tropical, and there's all sorts of fossils in the rocks to demonstrate that kind of environment. So Gondwanaland, which Antarctica was part of, slowly split apart, and ultimately the Antarctic part drifted down to pretty much over the South Pole. At either pole the Earth is much colder, and it's generally just much easier for ice to build up. But what you need for lots of ice to build up is a landmass. So that's why we have so much ice in Antarctica. I'm hoping to be involved in some research in a place called Thwaites Glacier, which is an area of West Antarctica where the ice is disappearing fast, and we want to know why. It's going to involve people going there and with radar trying to see what's happening down there.”
For further information about Antarctica, please see the Earthfiles Archive.
A few of many in-depth reports are listed below from the more than 2,500 in-depth reports organized in chronological order from 1999 to 2017 ongoing.
Robert Bingham, Ph.D., School of Geosciences, Edinburgh University, Scotland:
"A New Volcanic Province: An Inventory of Subglacial Volcanoes in West Antarctica," May 29, 2017, The Geological Society of London: http://sp.lyellcollection.org/content/specpubgsl/early/2017/05/26/SP461.7.full.pdf
"Antarctica: What Would Happen If All the Volcanoes Buried Beneath the Ice Erupted?" Sept. 5, 2017, Newsweek: