Tag Archives: volcanos

Alaskan volcanos could cause trans-Atlantic airline chaos

Volcanoes may soon disrupt airline travel around the world. We have paid little heed due to our short social memories and because the aviation industry developed in a period of relative calm, write Pyne-O'Donnel and Jensen.  Above,  Mount Baker in Washington State (with Lesser Snow Geese in the foreground) has shown signs of activity since 1975, say scientists. Photo by Deborah Jones, © 2014

Volcanoes may soon disrupt airline travel around the world. We have paid little heed due to our short social memories and because the aviation industry developed in a period of relative calm, write Pyne-O’Donnel and Jensen. Above, Mount Baker in Washington State (with Lesser Snow Geese in the foreground) has shown signs of activity since 1975, say scientists. Photo by Deborah Jones, © 2014

By Sean Pyne-O’Donnell, Queen’s University Belfast and Britta Jensen, University of Alberta
November 21, 2014

A volcanic eruption in Iceland caused massive disruption throughout Europe in 2010. A huge ash cloud grounded more than 100,000 flights and delayed 10m passengers, costing the aviation industry more than £2 billion. This wasn’t a freak event. New evidence shows such ash clouds are more common than we thought, and they can even cross the Atlantic from volcanic hot-spots in North America.

We need to be wary as another major ash cloud could arrive at any time. In fact, the ash has barely settled from Alaska’s latest major eruption.

Given volcanoes erupt all the time it seems odd that the Iceland incident came as such a shock. Perhaps there is a failure to appreciate that volcanic eruptions often occur in cycles with busy periods followed by intervals of relative quiet during which time these events pass out of social memory.

Looking back through history one can see that 2010 was by no means unique. The Icelandic volcanoes Katla and Hekla, for example, produced large ash plumes in 1947 and 1918, but both were modest by comparison with the massive Asjka eruption of 1875 which blanketed much of Scandinavia in ash.

We should remember that intercontinental plane travel has only existed for around 50 years, with budget airlines allowing mass air travel only within the past few decades. Flying has changed from being the reserve of the wealthy to a regular travel expectation for the majority.

The industry was lucky to evolve in what was a relatively quiet period between major ash producing eruptions in Iceland.

A few years ago we were involved in a project to reconstruct past environmental changes along North America’s east coast. We found a number of ash layers throughout the sediments covering the past several thousand years.

By analysing the elements in the ash’s glass particles we are able to obtain a chemical “fingerprint” unique to that ash layer. These “fingerprints” can then be compared with samples from elsewhere. When an ash layer is identified, it provides a means of joining and aligning the environmental histories of different areas where it occurs. They are very precise time markers in the sediment because they are deposited over a very short period of time (days to weeks).

Digging for Alaskan ash in an Irish bog. Gill Plunkett, Author provided

Digging for Alaskan ash in an Irish bog. Photo by Gill Plunkett, author provided

The majority of the dozen or so ash layers we found during this study were from well-known eruptions in North American volcanic regions such as the Aleutian Islands off Alaska or the Cascade Mountains near Portland.

One layer however stood out. It presented us with a puzzle: we had found a chemical match between an ash layer from Alaska and a layer which occurs throughout Europe, which was always presumed to come from Iceland. Using the ages of the eruptions was no help as they both occurred at approximately the same time. In North America, we know this as the White River Ash, which erupted from Bona-Churchill massif in Alaska. The European layer is called the AD860B (named after the approximate date of the layer).

We suspected both derived from the same eruption. But this would imply that ash would be capable of travelling from Alaska, over North America, and out across the Atlantic to Europe – a total distance of 7,000km. One might expect this of past mega-eruptions such as Toba on Sumatra which blasted ash as far as Lake Malawi in eastern Africa around 75,000 years ago.

However, the White River Ash was by no means a mega-sized event. Although it was large – approximately ten times larger than the 1990 eruption of Pinatubo – it was also half the size of the 1815 eruption of Tambora. In the long run we could expect an eruption the size of White River somewhere in the world every 100-200 years.

We collected samples of both the White River Ash and AD860B from both sides of the Atlantic and re-examined them in detail: there were no appreciable differences between the Alaskan and European ash deposits. As an added bonus the ash has also been found deep in the Greenland ice. This allowed us to count the annual ice layers as one would for tree rings to obtain a new age for the eruption of around AD 847.

It is unlikely that we stumbled upon the only time North American ash that made it to Europe, and we fully expect more such layers will be found to correspond with the many large eruptions that have occurred in North America. If it happened at least once before, we need to be aware of the risk that it will happen again.

The White River Ash/AD860B layer covered a third of the globe’s circumference at approximately 60°N. This coincides with a number of trans-Atlantic flight paths and would pose an obvious hazard when any of North America’s plentiful volcanoes have a White River Ash-type eruption.

Findings such as ours should provide additionally useful data for the airline industry when calculating the risk likelihood associated with future volcanic eruptions and how to improve resilience against them.

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The Conversation

White River Ash under the microscope. Photo by Britta Jensen, © 2014

White River Ash under the microscope. Photo by Britta Jensen, © 2014

Sean Pyne-O’Donnell, Post-Doctoral Research Fellow at Queen’s University Belfast, receives funding from The European Research Council.

Britta Jensen, Post-Doctoral Research Fellow at University of Alberta, receives funding from Natural Sciences and Engineering Council of Canada (NSERC).

This article was originally published on The Conversation. Read the original article.

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Survival Lessons in Iceland’s Resilience

Heimay, Iceland, was nearly destroyed by a volcanic explosion above it, more than four decades ago. Residents not only prevailed, but benefitted from the devastation, writes Johanna Hoffman.  Photo by kitniederer via Flickr, Creative Commons

Heimay, Iceland, was nearly destroyed by a volcanic explosion above it, more than four decades ago. Residents not only prevailed, but benefitted from the devastation, writes Johanna Hoffman. Photo by kitniederer via Flickr, Creative Commons

By Johanna Hoffman, The Daily Climate
October 24, 2014

HEIMAY, Iceland – The grassy slopes above this small Icelandic fishing town exploded with lava and ash 41 years ago. Rolling meadows erupted into a raw volcano and columns of 2,000º molten rock burst from the Earth. The surprise five-month eruption nearly destroyed the town.

Yet residents found ways to not only return but benefit from the devastation.

That Heimay’s townspeople bounced back with speed and agility is no accident. For Icelanders, long tested by fire and ice, resiliency to environmental change is par for the course.

As climate change threatens us all with stress and surprise, we would do well to learn from their ways. Design and planning can help us cope with – and even embrace – uncertainty and instability in our cities. Like the people of Heimaey, we can learn to take shelter in shifting ground.

Change, for Icelanders, is a fact of life. Earthquakes happen regularly. Volcanic eruptions come and are accommodated when they do. Asked about the 1973 explosion, a Heimaey barista shrugged: “It was stressful, but we managed.” Such is life on the Mid-Atlantic Ridge.

Across the rest of the developed world, natural hazards spark the opposite reaction. Ever since industrialization gave us the tools for large-scale engineering, we’ve set about armoring landscapes and minimizing environmental change. Manhattan’s marshes were filled and shored up to foster international trade. The Netherlands, reeling from devastating flooding of the Rhine in 1953, launched the Deltaworks project, one of the most extensive systems of dikes and dams in the world.

This reliance on hard engineering to keep natural forces at bay has left us vulnerable. Sandy overwhelmed Manhattan’s shoreline fill, crippling the region. Hurricane Katrina almost wiped a major American city off the map. The mighty dams and levees of the Mississippi couldn’t hold back 2011’s crushing spring floods, resulting in $3.4 billion in direct damages.

On Jan. 23, 1973, the island of Heimaey ripped open. As tremors in the Earth let loose spews of molten lava, farmers shot their cattle, fishermen abandoned their boats in the harbor and nearly all 5,300 residents fled to the mainland. For months, fire rained across the island, houses burned and ash fell twenty feet deep. By the time things fell quiet five months later, Eldfell loomed 600 feet high, a raw volcano where before there was only grass.

As lava began to pour across the island, Icelanders realized the major center of their country’s fishing industry – Heimaey’s harbor – was about to be blocked from the sea. Fishing is so central to Iceland that the country puts a different fish, crustacean or dolphin on each coin. John McPhee, writing in Control of Nature, put the dilemma in perspective: Proportionally Heimaey was more valuable to Iceland than Manhattan was to Americans.

Controversial tactics got the go-ahead. Physicist Thorbjorn Sigurgeirsson proposed spraying the lava’s face with seawater to cool and redirect the flow. Crews set to work with fire hoses, a dredging boat, and finally industrial pumps. The $1.5 million intervention worked: The lava flows were slowed, then diverted. Residents who returned came home an island 20 percent larger, with a more protected harbor.

The lesson here is that resilience can be cultivated. Heimaey’s resilience to Eldfell’s explosive force stemmed from two key factors.

One, residents had a strong understanding of their island’s landscape dynamics. Understanding the natural forces that shape our landscapes helps prepare us both practically and psychologically for how those landscapes can change.

Two, Icelandic culture is shaped by robust social ties and strong governing institutions. We can cooperate better and act quicker if we foster strong connections with people – from neighbors to government officials – who share our landscapes.

Both factors are key in developing resiliency to intense environmental change.

The 1995 Chicago heat wave offers a vivid – and tragic – example of the importance of social ties. More than 700 people died, many elderly, as polluted urban air trapped the sweltering heat. Sociologist Eric Klinenberg examined the impact of the event on two adjacent neighborhoods, and found striking differences.

One neighborhood was poor and largely elderly but dotted with small commercial establishments that encouraged residents to socialize. The death toll there was three out of every 100,000 people.

The other neighborhood, also poor and elderly, lacked commercial business and had less social action on the street. Its death toll was more than 10 times higher – 33 out of every 100,000 people.

Regular social interactions, it turns out, give residents a common understanding of who needs help and how to reach them. Those social ties, Klinenberg concludes, can go a long way in helping cities cope with the increasingly unpredictable events – from heat waves to hurricanes – stemming from climate change.

Just as important are a given group’s cultural mores. Christine Wamsler, author of Cities, Disaster Risk and Adaptation and associate professor at Sweden’s Lund University, finds that longstanding capacity for adaptation often results from how connected a given culture is to its landscape.

In Japan, for instance, negotiating a tsunami is a significant part of national culture. Folktales, paintings and photographs all repeatedly depict the act of retreating to high ground when tsunami comes. When coastal waters start to surge, citizens know what to do.

This is where planning and design can help. When well done, they are powerful tools to cultivate better understanding of our landscapes and the people with whom we share them.

New Yorkers may not be well aware of the risks that come with living on the Hudson Estuary these days, but they soon will be, thanks to bigger storm surges and extreme tides. Smart design moves now could save considerable heartbreak and cash, as well as get residents accustomed to dealing with environmental change.

Some of that change is already underway. Since Sandy revealed the region’s vulnerability to flooding and inundation, new waterfront projects are replacing the old seawall paradigm with tidal inlets and urban beaches to connect residents with river dynamics.

On the opposite American coast, San Francisco also risks inundation from sea level rise. Designs for its shoreline could include water plazas and floating piers that would allow users to better understand the intensity of tides and the harshness of winter storms. In Las Vegas, massive light shows could be re-wired as public art installations to communicate water usage levels in the increasingly water-poor city.

Planning and design can also play fundamental roles in strengthening our social networks.

Long before Eldfell exploded, Heimaey’s harsh winters and violent storms had taught residents how to cooperate and rebuild. Those strong social ties likewise extended to Heimaey’s relationship with the Icelandic government, whose swift actions were key in saving the town and its harbor. We can cultivate those ties by pushing for development that fosters connections between residents and nurtures economic development.

Designing housing within walking distance from stores creates opportunities to strengthen relationships between neighbors. Promoting public transportation sets the stage not just for more chance encounters, but for the sense of shared experience.

Given the uncertainties climate change is throwing our way, it’s time to learn from Heimaey’s example. We can’t stop the ground from shifting beneath us but we can learn to shift with it when it does.

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Johanna Hoffman is a landscape architect, coastal adaptation strategist and writer on climate change and its impacts on the built environment. She lives in California’s San Francisco Bay area.  This essay was originally published by The Daily Climate, an independent news service in the United States covering energy, the environment and climate change.

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“Volcano Season” — is it real?

Bárðarbunga Volcano, peterhartree

Bárðarbunga Volcano, Iceland. Photo by Peter Hartree via Flickr, Creative Commons

By Robin Wylie, University College London
October 4, 2014

The Earth seems to have been smoking a lot recently. Volcanoes are currently erupting in Iceland, Hawaii, Indonesia and Mexico. Others, in the Philippines and Papua New Guinea, erupted recently but seem to have calmed down. Many of these have threatened homes and forced evacuations. But among their less-endangered spectators, these eruptions may have raised a question: Is there such a thing as a season for volcanic eruptions?

Surprisingly, this may be a possibility. While volcanoes may not have “seasons” as we know them, scientists have started to discern intriguing patterns in their activity.

The four seasons are caused by the Earth’s axis of rotation tilting towards and away from the sun. But our planet undergoes another, less well-known change, which affects it in a more subtle way. Perhaps even volcanically.

Due to factors like the gravitational pull of the sun and moon, the speed at which the Earth rotates constantly changes. Accordingly the length of a day actually varies from year to year. The difference is only in the order of milliseconds. But new research suggests that this seemingly small perturbation could bring about significant changes on our planet – or more accurately, within it.

In February 2014, a study in the journal Terra Nova showed that, since the early 19th century, changes in the Earth’s rotation rate tended to be followed by increases in global volcanic activity. It found that, between 1830 and 2013, the longest period for which a reliable record was available, relatively large changes in rotation rate were immediately followed by an increase in the number of large volcanic eruptions. And, more than merely being correlated, the authors believe that the rotation changes might actually have triggered these large eruptions.

Altering the spin of a planet, even by a small amount, requires a huge amount of energy. It has been estimated that changes in the Earth’s rotation rate dissipate around 120,000 petajoules of energy each year – enough to power the United States for the same length of time. This energy is transferred into the Earth’s atmosphere and subsurface. And it is this second consequence that the Terra Nova authors believe could affect volcanoes.

The vast quantities of energy delivered to the subsurface by rotation changes are likely to perturb its stress field. And, since the magma which feeds volcanic eruptions resides in the Earth’s crust, stress variations there may make it easier for the liquid rock to rise to the surface, and thereby increase the rate of volcanic eruptions.

The Terra Nova study is far from conclusive. Nevertheless, the idea that minute changes to the Earth’s spin could affect volcanic motions deep within the planet is an intriguing one.

But there’s another natural phenomenon which has a much stronger claim to affect volcanic activity – one which might be just as surprising: climate change.

In recent decades, it has become apparent that the consequences of planetary ice loss might not end with rising sea levels. Evidence has been building that in the past, periods of severe loss of glaciers were followed by a significant spike in volcanic activity.

Around 19,000 years ago, glaciation was at a peak. Much of Europe and North America was under ice. Then the climate warmed, and the glaciers began to recede. The effect on the planet was generally quite favourable for humankind. But, since the mid-1970s, a number of studies have suggested that, as the ice vanished, volcanic eruptions became much more frequent. A 2009 study, for example, concluded that between 12,000 and 7,000 years ago, the global level of volcanic activity rose by up to six times. Around the same period the rate of volcanic activity in Iceland soared to at least 30 times today’s level.

There is supporting evidence from continental Europe, North America and Antarctica that volcanic activity also increased after earlier deglaciation cycles. Bizarrely, then, volcanic activity seems – at least sometimes – to rise and fall with ice levels. But why? Again, this strange effect might be down to stress.

Ice sheets are heavy. Each year, Antarctica’s loses around 40 billion tonnes. They are so heavy, in fact, that as they grow, they cause the Earth’s crust to bend – like a plank of wood when placed under weight. The corollary of this is that, when an ice sheet melts, and its mass is removed, the crust springs back. This upward flexing can lead to a drop in stress in the underlying rocks, which, the theory goes, makes it easier for magma to reach the surface and feed volcanic eruptions.

The link between climate change and volcanism is still poorly understood. Many volcanoes do not seem to have been affected by it. Nor is it a particularly pressing concern today, even though we face an ice-free future. It can take thousands of years after the glaciers melt for volcanic activity to rise.

Yet while it may not be an immediate hazard, this strange effect is a reminder that our planet can respond to change in unforeseen ways. Contrary to their brutish reputation, volcanoes are helping scientists understand just how sensitive our planet can be.

The ConversationCreative Commons

Robin Wylie, PhD researcher in Volcanology at University College London, does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.

This article was originally published on The Conversation. Read the original article.

 

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