Super Volcano Will Challenge Civilization, Geologists Warn

The eruption of a super volcano "sooner or later" will chill the planet and threaten human civilization, British scientists warned Tuesday.

Several volcanoes around the world are capable of gigantic eruptions unlike anything witnessed in recorded history, based on geologic evidence of past events, the scientists said. Such eruptions would dwarf those of Mount St. Helens, Krakatoa, Pinatubo and anything else going back dozens of millennia.

"Super-eruptions are up to hundreds of times larger than these," said Stephen Self of the United Kingdom’s (U.K.) Open University.

"An area the size of North America can be devastated, and pronounced deterioration of global climate would be expected for a few years following the eruption," Self said. "They could result in the devastation of world agriculture, severe disruption of food supplies, and mass starvation. These effects could be sufficiently severe to threaten the fabric of civilization."

Self and his colleagues at the Geological Society of London presented their report to the U.K. Government's Natural Hazard Working Group.

"Although very rare these events are inevitable, and at some point in the future humans will be faced with dealing with and surviving a super eruption," Stephen Sparks of the University of Bristol told LiveScience in advance of Tuesday's announcement.

The warning is not new. Geologists in the United States detailed a similar scenario in 2001, when they found evidence suggesting volcanic activity in Yellowstone National Park will eventually lead to a colossal eruption. Half the United States will be covered in ash up to 3 feet (1 meter) deep, according to a study published in the journal Earth and Planetary Science Letters.

Explosions of this magnitude "happen about every 600,000 years at Yellowstone," says Chuck Wicks of the U.S. Geological Survey, who has studied the possibilities in separate work. "And it's been about 620,000 years since the last super explosive eruption there."

Past volcanic catastrophes at Yellowstone and elsewhere remain evident as giant collapsed basins called calderas.

A super eruption is a scaled up version of a typical volcanic outburst, Sparks explained. Each is caused by a rising and growing chamber of hot molten rock known as magma.

"In super eruptions the magma chamber is huge," Sparks said. The eruption is rapid, occurring in a matter of days. "When the magma erupts the overlying rocks collapse into the chamber, which has reduced its pressure due to the eruption. The collapse forms the huge crater."

The eruption pumps dust and chemicals into the atmosphere for years, screening the Sun and cooling the planet. Earth is plunged into a perpetual winter, some models predict, causing plant and animal species disappear forever.

"The whole of a continent might be covered by ash, which might take many years -- possibly decades -- to erode away and for vegetation to recover," Sparks said.

Yellowstone may be winding down geologically, experts say. But they believe it harbors at least one final punch. Globally, there are still plenty of possibilities for super volcano eruptions, even as Earth quiets down over the long haul of its 4.5-billion-year existence.

"The Earth is of course losing energy, but at a very slow rate, and the effects are only really noticeable over billions rather than millions of years," Sparks said.

The odds of a globally destructive volcano explosion in any given century are extremely low, and no scientist can say when the next one will occur. But the chances are five to 10 times greater than a globally destructive asteroid impact, according to the new British report.

The next super eruption, whenever it occurs, might not be the first one humans have dealt with.

About 74,000 years ago, in what is now Sumatra, a volcano called Toba blew with a force estimated at 10,000 times that of Mount St. Helens. Ash darkened the sky all around the planet. Temperatures plummeted by up to 21 degrees at higher latitudes, according to research by Michael Rampino, a biologist and geologist at New York University.

Rampino has estimated three-quarters of the plant species in the Northern Hemisphere perished.

Stanley Ambrose, an anthropologist at the University of Illinois, suggested in 1998 that Rampino's work might explain a curious bottleneck in human evolution: The blueprints of life for all humans -- DNA -- are remarkably similar given that our species branched off from the rest of the primate family tree a few million years ago.

Ambrose has said early humans were perhaps pushed to the edge of extinction after the Toba eruption -- around the same time folks got serious about art and tool making. Perhaps only a few thousand survived. Humans today would all be descended from these few, and in terms of the genetic code, not a whole lot would change in 74,000 years.

Based on the latest evidence, eruptions the size of the giant Yellowstone and Toba events occur at least every 100,000 years, Sparks said, "and it could be as high as every 50,000 years. There are smaller but nevertheless huge eruptions which would have continental to global consequences every 5,000 years or so."

Unlike other threats to mankind -- asteroids, nuclear attacks and global warming to name a few -- there's little to be done about a super volcano.

"While it may in future be possible to deflect asteroids or somehow avoid their impact, even science fiction cannot produce a credible mechanism for averting a super eruption," the new report states. "No strategies can be envisaged for reducing the power of major volcanic eruptions."

The Geological Society of London has issued similar warnings going back to 2000. The scientists this week called for more funding to investigate further the history of super eruptions and their likely effects on the planet and on modern society.

"Sooner or later a super eruption will happen on Earth and this issue also demands serious attention," the report concludes.

Congratulations. You actually can form a complete (if unsubstantiated and erroneous) argument. I stand corrected.

In case you forgot, this all began with your unsolicited post to me, after I informed another FREEPER that the TV docudrama program in question was likely to be on the Discovery cable channel, which boiled down to this bit:

This is absolute hogwash, according to all but a handful of geologists. The "Tsunami Society" was very critical of such claims.

Well, the "Tsunami Society" is not a recognized purveyor of "TRUTH" in this field and a mention of (not even a link) to a (very unprofessional) web site does not constitute citing evidence to back up your bald claim that "this is hogwash." And the evidence I have come across in a very simple search of bona fide UNIVERSITY and RECOGNIZED PROFESSIONAL RESEARCH CONFERENCES clearly makes your claim false, on it's face, that "all but a handful of geologists" disagree with this theory. It is still an open question. Your claim is bogus.

And to your little challenge at the end of your post:

Please state what YOU actually believe and discuss the details rather than just say that there are people who believe both ways.

Fine, here you go:

I believe that it is likely that large volcanic island collapse events can cause catastrophic tsunamis, almost certainly far more devastating than the Indonesia tsunami of 2005 and that the overwhelming, though not conclusive, evidence supports that position. More importantly, I believe that irrelevant attempts to dismiss such speculation as "hogwash" are not only ill advised, they are clearly silly and, in fact, dangerous.

I mentioned this before, but it is all to similar to the dismissive attitude of the folks that ignored concerns about launching the Shuttle Challenger when temperatures were below freezing.

Have you ever heard the phrase "this is away from goodness?" You say you are "quite capable of googling." Fine. Do a Google search on that phrase and learn something about both Murphy and Finagle. Do you even know who Murphy is? If you are, as you say, an engineer, you shouldn't need to look that up. If you are an engineer I would be very afraid of partaking of any structure or design that you were involved with based on your attitude expressed in this exchange.

Ignoring, as you have, the arguments of professionals in the field in a dismissive way about concerns raised over a serious question is a really bad thing to do. Doing so with no more "evidence" than a vague mention of an amateur "society" that supports your claim is ludicrous.

Is it proven? No. Did a TV channel hype the presentation? Yep. Does that have anything to do with whether or not the question raised is of concern or the conclusion reached is correct? Not a chance.

Have you ever heard of "peer review?"

Again, rather than discuss the issues calmly, you seem to only be able to react angrily to scrutiny of the theories of Simon and Ward. I have not once made a personal comment about your ability to reason. Yet you cannot refrain, apparenly from doing likewise. But I raised very common sense issues regarding the comparison of the Indian Ocean and the Day/Ward theories of Cumbre Vieja, and you refused to address even one. All you come back with is harsh criticism to even question this theory unless I wore the title of geophysicist or hydrodynamicist. I have gone back and re-read Simon Day's paper on the La Palma possibility, and I am no more impressed with his thesis. I followed your suggestion and researched the Hawaii 2003 conference. Everything points back to Simon and Ward. As far as I can tell, they are the main proponents for the La Palma mega-tsunami and the magnitude suggested. I have not yet found experts who sign on to the magnitude of the effects predicted by Simond and Ward. Please point me to some. I searched on Gillis and did not find him specifically commenting on La Palma.

I have not disputed the chance that landslide-based tsunamis have occurred in the geologic past. That is both hard to prove or disprove. My comments have always been directed at Day and his La Palma theory, particularly the magnitude of the effects he predicts.

Have you read Day's thesis? Can we discuss the issues without name calling? What do you think about his prediction that the slide would be 100 m/s into the sea? He describes a sub-marine slide that slides from sea-level to sea-floor 4000 meters deep over a distance of 60km. Now, I don't know how linear the slope is, but that is an average grade of only about 6.5 degrees. He assumes nearly no basal friction (calls it a pressurized mud cushion). I find it hard to believe that, even in the absence of basal friction, that gravity (the prime cause of the slide) would cause such a fast slide across a mere 6.5 degree grade. He generally chooses worst-case scenarios (500 km^3 volume, 100 m/s, and the assumption that the slide will be one big block).

I also have a problem with his wave-propagation simulation technique. While his mathematical model appears very complicated, it is likely (my opinion... blast away) that it is in reality woefully inadequate, with way too much uncertainty built into it. The model is a function of both time and the radial distance away from the landslide. The problem I have with this simulation is:

1) Any error inherent in his model would be magnified/multiplied the further in time and also in radius.So while it may be accurate within the first few km's, the error across the ocean would likely be so large as to be useless.
2) There is no practical way to measure the validity of the simulation. You can test it on small scale models (little aquariums, etc) but there really is no practical way calibrate his model/simulation as there has not been volcanic collapses to test the model on. I'm familiar with the Lituya Bay slide in Alaska, but that took place in what was essentially a big bowl, not really similar to large-distance wave propagations due to landslides.
3) His model appears to be one that merely predicts amplitudinal waves... not the type that are normally associated with long-distance tsunami propagations. My problem with this is that the strength of most tsunamis I am aware of comes from transverse wave... pressure waves... where the wave amplitude above sea-level (the basis for Day's model) is not the important factor. Wave amplitudes above sea level dampen relatively quickly, and do not have the propagation efficiency of transverse waves. An amplitudinal wave can propagate, but not be devastating because it is largely local up and down circles near the surface of the water. They can produce a fairly large crash on a beach, but the water does not continue to surge onto the beach like a tsunami. His model is basically a standing wave model that propagates radially. I don't think it allows for additive or subtractive interference with existing wind-based ocean swells.

Believe it or not, I am really open to you changing my opinion. I have examined critically Day's theory and find it highly speculative, and somewhat sensational. I wish you would address the issues I have raised rather than insult me and tell me I haven't the aptitude to question these theories or to tell me to Google. If you have specific instances of experts backing this theory, please, by all means show me a link.

Also, rather than just blithely labeling the Tsunami Society as an amateur group, please back up your charges with real sources.

Believe it or not, I am really open to you changing my opinion. (on landslide caused mega tsunamis)

Believe it or not, I was never interested in changing your opinion, such as it is, on the topic.

HOGWASH, according to all but a handful of geologists.

I beg to differ. It is hogwash.

Most scientists agree

My only interest was in getting you to stop making bald statements of unverified opinion as if they were gospel and citing "expert testimony" and "evidence" like the always reliable "most scientists." It took quite a bit of prodding to get you to actually look anything up and point to it.

I have succeeded beyond my wildest dreams. I don't buy your reasoning and I'm skeptical of your newly discovered sources, but since I don't care to pursue this any further with you, I'll just say goodbye and good luck.

I don't buy your reasoning and I'm skeptical of your newly discovered sources, but since I don't care to pursue this any further with you, I'll just say goodbye and good luck.

I am as weary of this exchange as you are. But, however, I have not belittled your position (as you repeatedly have don with mine, including your latest post) except to point out, as I will one more time, that you do nothing to back up your position with any details. I have begged you to address details I have raised, and the best you come back with is "I don't buy your reasoning." Well, just why don't you "buy my reasoning"? It would have been nice to calmly and intelligently discuss details with you. Maybe get negative, but constructive, feedback on points that I raised. I have gone into great detail about the faults I have with Day/Wards theory, but you only broadly dismiss it. Surely, you are as bad at dismissing my arguments as you accuse me of dismissing the arguments of Day and Ward (and McGuire too... don't want to leave him out). I have accepted that you will not discuss details. I have many more points I could make, particularly regarding conclusions of the Hawaii Tsunami Conference and how they relate to Simon Day's paper on La Palma, but I accept that you are not interested in doing anything but roundly criticizing some rhetoric I used.

Good luck to you as well.

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