NO FLY ZONE
Scientists find it difficult to predict volcano behavior
by Joel Achenbach / April 21, 2010
The year of the earthquake has suddenly become the year of the volcano. The eruption in Iceland is not large as volcanoes go, but the cloud over Europe has shed light on the awkward overlay of human commerce and a hot, churning, unpredictable Earth. It raises the question of what governments can do to prepare for — and adapt to — wild-card geological events that not only affect airliners but can also alter the planet’s climate for years at a stretch. The volcano with the difficult name of Eyjafjallajokull is not powerful enough to change the climate — it has ejected material only as high as about 20,000 feet and would need to launch the ash to at least 33,000 feet to have global climatic effects, according to the National Oceanic and Atmospheric Administration (NOAA).
Now airports are beginning to open again in Britain and the Netherlands, but no one can be entirely sure what will happen next in Iceland. Eyjafjallajokull could incite an eruption of its larger neighbor, Katla, which hasn’t erupted since 1918 and might be ready to rumble. In all three historically recorded eruptions of Eyjafjallajokull — in 920, 1612 and 1821 — Katla erupted soon thereafter. “The eruption that’s going on right now is small in comparison to what we expect Katla would be like,” said Jay Miller, a volcanologist at Texas A&M University. Events in recent days have demonstrated the inherent uncertainties of volcano science. Although volcanoes are far more predictable than earthquakes, they remain quirky, with each one having its own personality. Scientists rely primarily on past performance to predict future activity for any given location. The Iceland volcano initially produced little ash, but a new vent opened beneath a glacier and the situation turned explosive. What precisely happened is still being researched, but it appears that meltwater and magma produced steam quite suddenly and the volcano popped its top like a shaken soda bottle.
No one knows how much material will be ejected, or how high into the atmosphere it will travel. Scientists using computer models are frantically trying to track plumes of ash that become widely and chaotically dispersed even as new ones shoot up. No one knows whether the ash will reach the airspace over the United States and affect domestic travel, though that doesn’t seem to be an imminent threat. The ash has reached eastern Canada, however. “I think there might be some nicer sunsets by the end of this week over North America,” said Stan Benjamin, director of the Forecast Research Branch of NOAA’s Global Systems Division. One National Weather Service scientist, Gary Hufford, told reporters in a conference call Tuesday that it can be difficult to tell with satellite imagery how much ash is in the air and whether the airspace is safe for jetliners. “The volcanic ash science still has many limitations,” he said. Asked whether he would be comfortable flying in Europe, Hufford paused and said, “I would be cautious.”
The lengthy shutdown of many European airports continues to surprise travelers and scientists. “It is kind of amazing. I imagined this in a big eruption. I didn’t imagine it in a small eruption,” said John Eichelberger, head of the U.S. Geological Survey’s Volcano Hazards Program, who is stranded in Paris, where he had attended a meeting on volcanoes. On Tuesday, the British Civil Aviation Authority revised its position to say that commercial jets could fly though areas that have low levels of ash. One top travel lobbyist said he suspected that officials had overreacted. “Are we all certain that we’re using the best scientific evidence? Are we aware of the economic impact of these decisions?” said Geoff Freeman, senior vice president of the U.S. Travel Association.
Air travel is particularly vulnerable to these geological events because the shortest international routes in the Northern Hemisphere take planes near Iceland, which seethes with volcanoes, and near the many cauldrons that line the Pacific “Ring of Fire.” The booming economies of Asia are also putting more planes over volcanoes in Indonesia, Papua New Guinea and the Philippines. “Volcanic risk is actually rising, not because we’re not doing our jobs, but because people are putting themselves nearer volcanoes, particularly with air travel,” said Marianne Guffanti, a geologist with the USGS. Said volcanologist Michael Rampino of New York University: “We live under the constant threat of some geological hazard. The more we all become technologically dependent upon others in other parts of the world, the more the problem shows up.”
Chris Waythomas, a USGS volcanologist based in Alaska, said it is easy to detect when a volcano is active but much harder to know what it will ultimately do, how long an eruption will continue and how big it will be. “There are surprises. Mount St. Helens, 1980: No one expected a major flank collapse to occur,” Waythomas said. That collapse depressurized the magma chamber below and caused the mountain to explode laterally. The United States has 169 volcanoes, most of them in Alaska, the Aleutian Islands and in territories in the Pacific Ocean (scientists will brief the Congressional Hazards Caucus on Wednesday). Geologists warn that scenic Mount Rainier, near Seattle, is one of the most hazardous.
One of the planet’s largest volcanoes is the huge caldera that feeds the hot springs and geysers of Yellowstone. Although it has been restless in recent months with hundreds of small earthquakes, there is no sign of the kind of dramatic doming of the ground that would indicate a major surge of magma and a potential eruption. The caldera last had a full-blown, catastrophic explosion about 640,000 years ago. The last significant eruption, known as the Pitchstone Plateau lava flow, took place 70,000 years ago. Jacob Lowenstern, the scientist in charge at the USGS Yellowstone Volcano Observatory, said tourists shouldn’t stay away for fear of what’s happening below.
photograph by Peter Vancoillie
photograph by Marco Fulle
Volcanoes can be mass killers. The relatively small eruption of the Nevado del Ruiz in Colombia in 1985 created a mud flow that buried more than 23,000 people in the town of Armero. Hot gas and ash from Mount Pelée on the island of Martinique rolled down the slopes and incinerated 30,000 people in 1902. Vesuvius, the volcano that buried the Roman city of Pompeii, is widely viewed as another disaster waiting to happen. It erupts about every 400 years and hasn’t had a large eruption since 1641, Rampino said. Hundreds of thousands of people live beneath it and could be hit with what are known as pyroclastic flows — extremely fast-moving, dense clouds of hot ash and rock that flow down the mountain. “They’d have 15 minutes’ warning,” Rampino said. “It would destroy everything in its path. It’s like an ash hurricane that’s 800 degrees Celsius.”
Second, more powerful Icelandic volcano likely to explode soon
by Martin Hickman / April 21, 2010
Despite grounding 100,000 flights across Europe, battering a beleaguered airline industry, stranding hundreds of thousands of travellers, disrupting schools and businesses, and giving homes under flight paths their first peace and quiet in decades, the current volcano eruption may be only a teaser of chaos to come. A far bigger Icelandic volcano, Katla, is tipped to erupt in the coming months, potentially causing much more savage and sustained disruption to industry and society. Eyjafjallajokull erupted on 14 April, forcing European governments to impose a no-fly zone. Each time Eyjafjallajokull has erupted in the past 2,000 years – in 920, in 1612 and between 1821 and 1823 – Katla has exploded within six months. “I certainly wouldn’t be surprised if Katla erupted within the next year, but how much it affects Britain and northern Europe depends on what happens with the winds at the time,” the volcanologist Bill McGuire told The Independent.
Professor McGuire, who sits on the Government’s Cobra emergency committee, pointed out that Katla was 10 times bigger than Eyjafjallajokull. It also has a much bigger ice cap, and it is the mixture of melting cold water and lava that causes explosions and for ash to shoot to high altitudes. Professor McGuire, a professor of geophysical and climate hazards at University College London, suggested airlines should draw up contingency plans for coping with Katla, which he said had been known about for a long time – but he added that there was probably not much that could be done. His concern was shared by Jon Davidson, a professor of Earth sciences at Durham University, who remarked that because Katla has invariably exploded into life after Eyjafjallajokull has done so, the aviation industry should be “less surprised” by its potential impact.
Iceland’s President, Olafur Grimsson, indicated that Europe, and the world, would have to wake up to the risk posed by Katla. He told the BBC’s Newsnight: “Unfortunately, what we have seen in the past few years could only be a beginning of an experience which might be repeated throughout the 21st century. “Because the history of these volcanoes in my country shows that they will erupt regularly, and the time for Katla to erupt is coming close. It’s much bigger. What we have seen now is a small rehearsal of what would happen, I don’t say if, but when Katla will erupt, because it usually erupts [on a large scale] every century and the last [major] one was in 1918.” The President said Iceland had been “waiting for that eruption” for some years, and had made preparations for rescue and emergency services. “So I think it is high time for European governments and airline authorities across the globe to start planning for the eventual Katla eruption,” he added.
A phone booth lies half-buried in volcanic ash after the eruption on Montserrat, 1998. photograph by Gregory Bull
VOLCANIC EXPLOSIVITY INDEX
Iceland volcano: why we were lucky we weren’t wiped out
by Simon Winchester / 21 April 2010
The map is almost uncannily similar to today’s: a spray of black dots showing the recorded sightings of a foul grey haze spreading across Europe, from Helsinki to Naples, from Heligoland to Mallorca, and reaching eventually to Aleppo and Damascus – and all of it caused by clouds of ash from an immense volcano erupting far across the sea in Iceland. But this was a map made from data collected in 1783. The volcano was called Laki, it erupted for eight dismal months without cease, ruined crops, lowered temperatures and drastically altered the weather. It killed 9,000 people, drenched the European forests in acid rain, caused skin lesions in children and the deaths of millions of cattle. And, by one account, it was a contributing factor (because of the hunger-inducing famines) to the outbreak six years later of the French revolution.
Great volcanoes have a habit of prompting profound changes to the world – very much greater in extent than the most savage of earthquakes and tsunamis, even though the immediate lethality of the latter is invariably much more cruel. Though ground-shaking events are generally fairly local in extent, their potential for killing can be terrific: 250,000 died after the Tangshan earthquake in China in 1975; and a similar number died in the Indian ocean tsunami of 2004. Volcanoes seem by contrast relatively benign: the accumulated total number of deaths in all of the great volcanoes of the last 300 years has probably not exceeded a quarter of a million: the total number of casualties from a hundred of the biggest recent eruptions has been no more than those from a single giant earthquake.
But there is a signal difference. Earthquakes and their aftershocks, once done, are done. Volcanoes, however, often trigger long-term and long-distance ill-effects, which history indicates generally far outweigh their immediate rain of death and destruction. Emanations of particles from the tiniest pinprick in the earth’s crust, once lifted high into the skies by an explosive eruption, can wind themselves sinuously and menacingly around the entire planet, and leave all kinds of devastation in their train. They can disrupt and pollute and poison; they can darken skies and cause devastating changes in the weather; they can and do bring about the abrupt end to the existence of entire populations of animals and people.
Earthquakes and tsunamis have never been known to cause extinctions; but volcanoes and asteroid collisions have done so repeatedly – and since the earth is today still peppered with scores of thousands of volcanoes ever yearning to erupt, they and the dramatic long-term effects of their eruptions are in fact far more frequent, far more decisive, and far greater than those that are triggered by any other natural phenomenon on the planet.
It is worth remembering that ours is a world essentially made from and by volcanoes. They are creatures that will continue to do their business over the aeons, quite careless of the fate of the myriad varieties of life that teems beneath them and on their flanks. Including, of course, ours. There is perhaps no better recent example of the havoc that a big eruption can cause than that which followed the explosive destruction of Mt Toba, in northern Sumatra, some 72,000 years ago (which, in geological time, is very recent indeed). The relics of this mountain today are no more than a very large and beautiful lake, 60 miles long and half a mile deep – the caldera that was left behind by what is by most reckonings the largest volcanic explosion known to have occurred on the planet in the last 25 million years.
On the widely used volcanic explosivity index (VEI), Toba is thought to have been an eight – meaning that in the unusually flamboyant official language of vulcanology it was a super-plinian type eruption with mega-colossal characteristics (Eyjafjallajökull is by contrast listed as a strombolian type, with its characteristic regarded as merely gentle, and having a probable VEI rating of just two). About 680 cubic miles of rock were instantly vaporised by the super-eruptive blast of Toba, all of which was hurled scores of thousands of feet into the air. This this is what did the lasting damage, just as Iceland’s high-altitude rock-dust is doing today. But while we today are merely suffering a large number of inconvenienced people and a weakening of the balance sheets of some airlines, the effect on the post-Toban world was catastrophic: as a result of the thick ash clouds the world’s ambient temperature plummeted, perhaps by as much as 5C – and the cooling and the howling wave of deforestation and deaths of billions of animals and plants caused a sudden culling of the human population of the time, reducing it to maybe as few as 5,000 people, perhaps 1,000 breeding pairs. Many anthropologists believe that the event caused a sudden evolutionary bottleneck, with genetic implications that linger to this day. Put more crudely, humanity was nearly wiped out by Toba, and only by the merest hair’s-breadth did our ancestors of 72,000 years ago manage to cling on and bequeath to us our current existence.
Mercifully, from humanity’s point of view, there have been very few Tobas known in planetary history. They are probably so large that they reach the upper limit of the kind of eruptions that can physically occur on earth – one VEI-8 event occurs only every 100,000 years or so. Yet of those known to have occurred, two have taken place in Britain (mainly because Britain has such a vast variety of geology, with almost every age of rock known in the world found somewhere between Cape Wrath and the Port of Dover). They are comfortingly ancient: both – the volcano that created Scafell in the Lake District, and the other that gave us Glen Coe in the Western Highlands – took place more than 400 million years ago.
But others of the 47 known VEI-8 volcanoes are more alarmingly recent. Taupo in New Zealand erupted with mega-colossal force some 22,500 years ago. The newer of the great eruptions that helped form the mountains of today’s Yellowstone national park in Wyoming took place just 640,000 years ago, and all the current signs – from such phenomena as the rhythmic slow rising and falling of the bed of the Yellowstone river, as if some giant creature is breathing far below – suggest another eruption is coming soon. When it does, it will be an American Armageddon: all of the north and west of the continent, from Vancouver to Oklahoma City, will be rendered uninhabitable, buried under scores of feet of ash. (I mentioned this once in a talk to a group of lunching ladies in Kansas City, soothing their apparent disquiet by adding that by “soon” I was speaking in geologic time, and that meant about 250,000 years, by which time all humankind would be extinct. A woman in the front row exploded with a choleric and incredulous rage: “What?” she said. “Even Americans will be extinct?”)
Ratcheting down the scale a couple of notches, to the only slightly less gigantic eruptions that are classified as VEI-7 and VEI-6, and a host of more familiar eruptions come into view. These include Santorini, the Aegean volcano whose destruction around 4,000 years ago may have triggered the collapse of the Minoan civilisation; Laki, the 1783 Icelandic volcano mentioned above, and which most obviously parallels today’s events at Eyjafjallajökull; the Javan volcano of Krakatoa, which erupted so infamously in August 1883; and the rather more profoundly world-affecting eruption of 1815, also in the Dutch East Indies, of the huge stratovolcano on Sumbawa Island, known as Tambora. Each of these had massive after-effects, and all of the effects were global in their extent.
Tambora is the most notorious, not least because it was so immense: almost 40 cubic miles of pulverised Sumbawan rock were hurled into the sky, which darkened, cooled and polluted a world that, unlike in Toba’s day, was already well populated and widely civilised. The consequences ranged from the dire – a lowering of temperature that caused frosts in Italy in June and snows in Virginia in July, and the failure of crops in immense swathes across Europe and the Americas – to the frankly ludicrous – Irish migrants, promised better weather in New England, found it on landing to be every bit as grim as the Connemara and Cork they had left, and so either went home, or pressed on in hope to California.
And Tambora’s eruption had its effects on art also: a gloomy Byron wrote the gloomiest of poems, Darkness (“Morn came and went, and came, and brought no day/ And men forgot their passions in the dread/ Of this their desolation . . .”); Mary Shelley, it is said, became so fed up with the rain while visiting Byron in Geneva that she followed suit and wrote her exceptionally gloomy novel Frankenstein. Only JMW Turner rose more cheerfully to the occasion: the lurid colours of many of his paintings, it is said, owe much to the flaming Tambora sunsets that had half the world astonished, and Turner evidently inspired.
Krakatoa’s immediate aftermath was dominated initially by dramatic physical effects – a series of tsunamis that were measured as far away as Portland Bill and Biarritz, a bang of detonation that was clearly heard (like naval gunfire, said the local police officer) 3,000 miles away on Rodriguez Island, and a year’s worth of awe-inspiring evening beauty – astonishing sunsets of purple and passionfruit and salmon that had artists all around the world trying desperately to capture what they managed to see in the fleeting moments before dark. A Londoner named William Ascroft left behind almost 500 watercolours that he painted, one every 10 minutes like a human film camera, from his Thames-side flat in Chelsea; Frederic Church, of America’s so-called Hudson River School, captured the crepuscular skies over Lake Ontario in their full post-Krakatoan glory; and many now agree that Edvard Munch had the purple and orange skies over Oslo in mind when 10 years afterwards he painted, most hauntingly, The Scream.
Yet there was an important legacy to Krakatoa’s eruption that was not shared by the other giant volcanoes of the time. Close mapping of the spread of the 1883 sunsets showed them girdling the earth in a curious set of spirals, the stratospheric aerosols evidently being borne around the world on high-altitude winds that no one at the time knew even existed. An atmospheric scientist in Hawaii mapped them and decided to call the air current the equatorial smoke stream; it later became, more elegantly and economically, the jet stream. There has to be some irony that the jet stream that drives today’s Icelandic dust so dangerously over Britain and mainland Europe is a phenomenon that was first discovered as a direct consequence of the study of Krakatoa.
And yet, of all the consequences of the truly great volcanoes of the past, the phenomenon of mass extinctions of life must surely be the most profound and world-changing of all. Between two and five major extinction events occur in the world every million years or so. We humans have not thus far been privileged to observe one of them – hardly surprisingly, since they would probably occur so slowly as to be barely noticeable. However, with painstaking care, palaeontological evidence is currently being amassed to link sudden and catastrophic changes in world climate, changes that promote such extinction crises, with the known major eruptions of the past, and with what are known as flood basalt events (such as those that have been triggered specifically in the past by eruptions of Eyjafjallajökull and her neighbouring volcano in Iceland, Katla, which is herself currently well overdue for an eruption). It is a study that opens up a fascinating speculative possibility.
For what if the kind of event that we have seen this month, and which caused us all in Europe such commercial inconvenience, is in fact not just a minor volcanic hiccup, but the beginning of an event that causes in time a mass extinction of some form of earthbound life? And further, since we know from the history books that the massive eruption of Santorini once had the power to destroy one proud part of human society, what if the extinction we might be beginning to see turns out to be what will one day surely occur, and that is the extinction of us?