Fire & Ice Volcanoes and frozen lands make an explosive combo

May 14, 2011 · Posted in Uncategorized · Comment 

Home / September 25th, 2010; Vol.178 #7 / Feature

Fire & Ice
Volcanoes and frozen lands make an explosive combo
By Alexandra Witze
September 25th, 2010; Vol.178 #7 (p. 16)
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FIRE AND ICE Iceland’s Eyjafjallajökull volcano erupted quietly at first this spring (shown), until magma shifted directly beneath a glacier.Odd Stefan Thorisson/Nordicphotos/Corbis

SVEIFLUHÁLS, Iceland — High atop an Icelandic mountain one magnificent summer day, with blankets of soft moss underfoot and a translucent lake shimmering in the valley below, geologist Emily Constantine Mercurio is conjuring up an image of hell.

Tens of thousands of years ago, says Mercurio, a graduate student at the University of Pittsburgh, this place was the heart of a roiling volcanic eruption. Molten rock bubbled up from a fissure in the Earth’s crust. On top of that lay hundreds of meters of ice. Lava met ice, and the result was an inferno.

Heat from the eruption instantly boiled ice to steam, which ramped up the eruptive power like a pressure cooker blowing its top. Magma hitting the steam exploded into tiny fragmented bits, sending pillars of fine-grained ash billowing overhead. It would have resembled the scene many people heard about on the news this spring — a volcano that erupted an hour’s drive to the east, known as Eyjafjallajökull (pronounced “AY-ya-FYAT-la-yo-kult”).

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THIN ICE, MORE EXPLOSIONSComputer modeling of volcanic eruptions under ice suggests that thin ice plus even a little magma equals hazardous explosive eruptions.Source: H. Tuffen/Phil. Trans. R. Soc. A 2010

Eyjafjallajökull began erupting on March 20, but few people other than volcanologists and Icelanders took notice at first. For weeks, all it did was spurt lava gently out of an exposed ridge. On April 14, though, the eruption suddenly shifted a few kilometers west — no longer on open land, but beneath an ice cap. Just as happened at Sveifluháls, magma met ice and turned it to steam, throwing ash into the stratosphere. European airline flights shut down for days over worries about how the ash might affect jet engines.

What a difference a little ice makes. Had the second phase of the eruption not shifted westward, the volcano would not have closed down much of Europe’s air traffic. “In the absence of ice, Eyjafjallajökull would have been a much less disruptive volcano,” says Dave McGarvie, a volcanologist at the Open University’s campus in Edinburgh.

Eyjafjallajökull’s eruption has refocused attention on a small but rapidly growing subset of volcanology: the study of volcano-ice interactions. Ice-covered volcanoes, or “glaciovolcanoes,” are not fundamentally different from other volcanoes in terms of plumbing or eruptive style. But they distinguish themselves the moment magma breaks through the crust and meets ice.

One reason to study icy volcanoes is to better understand their risks. Nobody died in the Eyjafjallajökull eruption, but in 1985 an eruption beneath an icy mountain in the Colombian Andes sent massive mudflows coursing downstream, killing more than 20,000 people. Dozens of volcanoes mantled with ice are scattered around the world, each posing a distinct hazard.

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GLACIOVOLCANOES AROUND THE WORLD| Volcanoes capped with ice pose distinct hazards in different countries. Researchers are trying to better understand these mountains to prevent future disasters.Cartesia, adapted by E. Feliciano

Scientists are also studying volcano-ice interactions to learn more about the past. By chronicling geologic signs that volcanoes like Sveifluháls once erupted under ice, researchers can build up a picture of how far ice extended over the planet, and when.

Icy volcanoes might even be a key to answering a vexing question — whether a warming climate could trigger more eruptions by lifting the heavy mantle of ice above volcanoes. As glaciers retreated from Iceland at the end of the last ice age, about 12,000 years ago, volcanic activity increased 10- to 30-fold. Some researchers speculate that the ongoing melting of ice caps worldwide could have a similar effect.

Land of ice volcanoes

Iceland is an ideal place to see icy volcanoes and for scientists to figure out how such volcanoes work. The country has some two dozen active volcanoes, of which Eyjafjallajökull is relatively puny. The island is so volcanically active because it is the above-water manifestation of the Mid-Atlantic Ridge, the chain of mountains that runs down the center of the Atlantic like an underwater backbone. Here Earth’s crust pulls apart, and upwelling magma cools and forms new crust that spreads away from the ridge in the great recycling process known as plate tectonics. Iceland is geology in action; a one-hour flight from Reykjavik skims over steaming geothermal areas, the great crustal rift and some of the country’s most famous volcanoes.

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ICELAND: LAND OF FIRE AND ICE1. Sveifluháls: An eruption thousands of years ago created this volcanic ridge.2. Eyjafjallajökull: This small volcano shut down much of Europe’s airspace this spring.

3. Katla: This neighboring volcano has erupted in tandem with Eyjafjallajökull before.

4. Hekla: One of Iceland’s most active volcanoes, it has erupted five times since 1947.

5. Gjálp: Its 1996 eruption spurred pioneering studies of glaciovolcanism in Iceland.

6. Grímsvötn: It last erupted in 2004, and many scientists think it will be Iceland’s next to go.

Cartesia, adapted by E. Feliciano

Many of those volcanoes are mantled in ice, including several under the 1,000-meter-thick Vatnajökull ice cap. Sometimes, thick ice can muffle a volcanic eruption entirely. At Eyjafjallajökull, though, the ice is only a couple of hundred meters thick at most. That’s not enough to keep the eruption from breaking through ice, though it is enough to generate lots of meltwater and steam when magma hits. “What the ice did was provide the trigger, the catalyst for the production of very fine ash,” says McGarvie. Surprisingly, and for reasons volcanologists don’t yet understand, Eyjafjallajökull kept churning out fine-grained ash for longer than expected.

Still, ice wasn’t the only thing that made the volcano produce so much ash. Another factor was the chemical makeup of the magma during the second phase of the eruption. In March, the magma that poured out was primarily basalt, a common lava type that makes up 90 percent of the volcanoes in Iceland. Magma in the April eruption, however, suddenly had more silica in it. Silica makes magma more viscous or sticky; gas bubbles can’t escape as quickly as they can in more fluid magma, and the whole mess rapidly becomes more prone to exploding.

Scientists are not sure why the magma composition changed from eruption to eruption, but one possibility is that Eyjafjallajökull began to tap a separate magma chamber. Another idea, says McGarvie, is that basalt erupting from deep within the volcano suddenly encountered a chamber of more silica-rich magma, and the two mixed before erupting under the ice.

It’s hard to untangle how much of Eyjafjallajökull’s power came from erupting under ice, and how much from the chemical composition of its magma. Volcanologists may eventually get a handle on that question by analyzing lavas from various stages of the eruption. Researchers led by Magnús Tumi Guðmundsson of the University of Iceland in Reykjavik have launched a full-out assault on the mountain to gather such information.

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SPECIAL HAZARDSAll volcanoes can be hazardous, but when magma hits ice as it emerges, the resulting mudflows (called lahars) and high-flying ash can be especially dangerous for nearby residents and airplanes.B. Myers and S.R. Brantley/USGS, adapted by E. Feliciano

Like the 1996 eruption of the Icelandic volcano Gjálp, whose study pioneered the field of glaciovolcanism, Eyjafjallajökull may end up as a linchpin in understanding these types of eruptions. “We will learn a great deal from this volcano,” McGarvie says.

Frozen past

Farther west, at Sveifluháls, Mercurio is doing her best to push such knowledge back in time, to create a window to glimpse the glaciovolcanic past. She is part of a new effort to study what tracks icy eruptions make in the geologic record.

When magma cools, it leaves distinctive textures in the resulting rocks, revealing the conditions under which they formed. Lava that is chilled quickly contains only small crystals; lava that takes longer to cool has time for larger crystals to grow. Fractures along the cooling edge can also indicate how dramatic the temperature difference was between the magma and whatever it encountered to cool it — air, water, ice or snow.

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ICE THINNING AT SELECTED ICE SHEETS AND VOLCANOES Source: H. Tuffen/Phil. Trans. R. Soc. A 2010

“It would be great if you can find lavas and say they must have cooled in contact with snow or ice or some other environment,” says volcanologist Hugh Tuffen of Lancaster University in England. “You could reconstruct changing ice and snow, and understand the way the behavior of the volcano has been coupled to that.”

Icelandic volcanoes can also be used to tackle important paleoclimatological questions, like how thick ice sheets got during the last ice age. While some measurements, such as the ratios of oxygen isotopes in trapped air bubbles, can tell scientists how cold temperatures were, that information can’t be translated directly into ice thickness. The only way to find out is through shoe-leather geology — mapping structures in the field and untangling the story of what transpired thousands of years ago.

That question is what brings Mercurio to Sveifluháls this gorgeous summer day. Her backup troops include her adviser, University of Pittsburgh volcanologist Ian Skilling; master’s student Holly Kagy; and a field assistant, Mercurio’s cousin Kathy Zollinger.

At first, Sveifluháls looks too huge to ever comprehend: a massive ridge of black rock, some 21 kilometers long. The barren landscape lies about a 40-minute drive south of Reykjavik. The gravel roads that run down either side of the ridge are usually empty of other cars, save for fishermen trying their luck in Lake Kleifarvatn or the occasional tourist heading to the mud pots at the local geothermal field.

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Geologist Emily Constantine Mercurio measures the orientation of ripples frozen in rock atop Sveifluháls in Iceland.A. Witze

But hiking up into the lunarlike terrain, Mercurio and Skilling start to point out geologic details that tell the story of the past inferno. Here in an outcrop amid a steep pile of scree lie pillow basalts — the billowy-looking rocks that form when lava erupts underwater. There, lower down the ridge, stretch the remnants of an ephemeral lake, its ancient coastlines marked along the edges. Such features mean water, and water means ice melted by lava. “We’re looking for evidence of drainage, all the way down the ridge,” Skilling says.

Summer after summer, Mercurio has been building up a history of what happened at Sveifluháls. She can’t be sure exactly when it erupted; the rocks here are too young for typical radioactive dating techniques. But at some point, probably between about 40,000 and 13,000 years ago, magma came bursting up through ice. Months later, when the eruption subsided, the ridge remained. More than 1,000 of these erupted ridges, called “tindar,” dot Iceland’s countryside.

In some places the researchers spot physical evidence of where ice used to be. Atop one section of the ridge,

Skilling points out a place where thick layers of cooled magma slump down and then are truncated abruptly at one end. The magma must have run into a wall of ice here, he says — cooling and stopping before the ice melted away.

Mercurio’s fieldwork suggests that the ice at Sveifluháls was some 400 meters thick at the end of the last ice age. Puzzlingly, models of Iceland’s ice cover suggest that it should have been 1,500 to 2,000 meters thick. Asked why the difference, Mercurio shrugs. Only more studies of glaciovolcanism can answer these kinds of questions.

Melting future

Northwest of Mercurio’s field site, a low gleaming office building in Reykjavik houses the earth science department of the University of Iceland — ground zero for probing the links between volcanoes past and present. Volcanologist Freysteinn Sigmundsson spends his days digging through data from Eyjafjallajökull and wondering what other eruptions are yet to come. “What will be the influence on volcanic activity if all the ice caps shrink?” he asks.

The disappearance of ice sheets lifts weight off the land, he says, and great pieces of Earth’s crust can rise with their backs unburdened. Many regions in northern latitudes, such as Scandinavia and Canada, are still uplifting from the pressure released when the great ice sheets retreated at the end of the last ice age. In Iceland, where an ice sheet some 300 kilometers wide has mostly disappeared, this “glacial rebound” is as much as 20 millimeters per year. In addition, glaciers worldwide are retreating because of rising global temperatures. Ice caps in Iceland, for example, have been thinning since around the year 1890.

Glacial rebound and thinning glaciers together can affect volcanic activity in multiple ways, Sigmundsson says.

For one, reducing pressure at the surface causes more magma to be produced at depth. “This is sort of excess magma,” Sigmundsson says. “If the conditions in the crust remain the same, you would expect more magma to make it to the surface.” The thinning of the Vatnajökull ice sheet, for instance, may have caused a 10 to 15 percent increase in magma production over the past century.

Ice loss also shifts areas of stress on buried magma chambers. Volcanologists know that ice loss can affect eruptions; in 2004, half a cubic kilometer of meltwater suddenly drained from a lake beneath Vatnajökull, and the nearby Grímsvötn volcano erupted. In cases where a volcano was about to erupt anyway, like Grímsvötn, a change in surface stress could provide the final trigger necessary to set it off, Sigmundsson says.

Finally, taking ice away also may open new channels for magma to find its way to the surface, via new fractures or fault lines.

Still, volcanologists argue about exactly what effect shrinking ice will have. At the end of the last ice age, volcanic activity in Iceland experienced a big pulse; activity was more than 10 times that seen today. Some have argued that the thinning of Vatnajökull has accelerated volcanic activity in central Iceland. But teasing out such processes from ordinary volcanism is not easy. And it’s not clear whether more volcanic activity might mean a greater number of eruptions, or the same number but with more magma volume in them.

Back atop Sveifluháls, such concerns seem remote. At 63° N latitude the sunlight has that rarefied Arctic feel, and the city of Reykjavik sparkles in the distance. An eruption amid the serenity seems a far-off possibility.

Yet as Mercurio will tell anyone who listens, the peace is deceiving. There’s no doubt that the geological demons driving Iceland’s volcanoes will be back.

 


The Eyjafjallajökull volcano grabbed international headlines this spring when it erupted beneath a glacier in southern Iceland, sending ash plumes high into the atmosphere and grounding air traffic across much of Europe. But scientists are interested in Eyjafjallajökull for a different reason: It’s a classic example of how eruptions under ice can be far more explosive than those on dry land. All images (except as noted): Alexandra Witze

Science News,  Society for Science & the Public 2000 – 2011

May 14, 1804: Lewis and Clark depart

May 14, 2011 · Posted in Uncategorized · Comment 
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When the Tulip Bubble Burst TULIPOMANIA

May 14, 2011 · Posted in Uncategorized · Comment 

The Story of the World’s Most Coveted Flower
By Mike Dash
Crown Publishers

Tulipomania
A tulip, known as “the Viceroy”, displayed in a 1637 Dutch catalog. Its bulb cost between 3000 and 4200 florins depending on size. A skilled craftsman at the time earned about 300 florins a year.[1] Read more

Psychologists Put “Character” Under the Microscope–and it Vanishes

May 13, 2011 · Posted in Uncategorized · Comment 

Authors David DeSteno and Piercarlo Valdesolo argue that much of our good and bad behavior is situational
By Gareth Cook | Tuesday, May 10, 2011 | 21

Author David DeSteno
Image: Andre H. Mehta
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What can science reveal about our “character” — that core of good, or evil, that shapes our moral behavior? The answer, according to a new book, is that there may not be much of a core, after all. In “Out of Character” scientists David DeSteno and Piercarlo Valdelsolo argue that how we think about character — a conception that dates back to at least the ancient Greeks — is deeply flawed. Our moral behavior, to a surprising degree, is shaped by the context in which we find ourselves. Mind Matters editor Gareth Cook spoke recently with DeSteno about the book, and the broader implications of the new science.

COOK: How did you become interested in the issue of character?

DESTENO: One of the main goals of my lab is to investigate how emotional responses guide social behavior. Most people are willing to believe that emotions can be useful to navigate the physical environment. For example, we feel disgusted at the sight of carrion, which prevents us from eating it. But for humans, navigating the social environment is just as important as navigating the physical one. For us, issues of trust, fairness, fidelity, intergroup conflict, and the like hold important consequences for successfully navigating our world.

Over the past decade of work, my lab has examined how changes in emotional states, often due to very subtle factors in one’s environment, can lead people to act in ways that they’d never expect: to be hypocrites, to lie, to cheat, but also to show compassion and kindness, and pride and leadership. What Piercarlo and I realized in looking back on this work is that, in essence, we were studying the factors that shape character – factors that, for most people, fly under their conscious radar. But of even more importance, what we saw was that the idea of character that most people posses is decidedly wrong.

What is wrong with our popular notions of “character”?

The derivation of the word “character” comes from an ancient Greek term referring to the indelible marks stamped on coins. Once character was pressed into your mind or soul, people assumed it was fixed. But what modern science repeatedly shows is that this just isn’t the case. As we discuss in our book, everyone’s moral behavior is much more variable than any of us would have initially predicted.

When you think about it, the way we reason about character isn’t logically consistent. Take someone like Gov. Mark Sanford. Irrespective of their political views, most people thought he was a morally upstanding guy until that fateful day he admitted crossing the “sex line” with a mistress. Then, suddenly, we all assumed that he must have always been deeply flawed – a wolf in sheep’s clothing, if you will. He had just been pulling the wool over our eyes. Fair enough, but then why, when Farron Hall, who was a homeless drug addict who lived under a bridge in Winnepeg risked his own life to save someone who fell in the river, why don’t we now assume that he is really a good guy? We seem to believe that one bad act marks a supposed good person as deficient in character, but not that one good act marks a supposed bad person as now noble.

At one point you say that the distinction between good and bad is ““passe.”“ Can you explain what you mean by that?

Sure. The usual motif for how character works is that you have an angel on one shoulder and a devil on the other, whispering into your ears. Early on in life, you decide to which voice you will listen, and that sets the direction for your life. The problem with this view is that, intense psychopathology aside, it makes little sense from an evolutionary perspective to assume that the mind would have “evil” mechanisms. What’s adaptive about being evil?

It makes much more sense to frame the two sides of the scale of character by immediate and forward-looking mechanisms – those that look for rewards in the short term and those that look in the long-term. In fact, social living requires finding the right balance between these two. Actions like borrowing money and not paying it back, or loafing on the couch instead of studying for the SAT’s, have immediate short terms rewards, but do them too often and no one else will want to associate with you. Similarly, always thinking of others and helping them at your own expense can lead you to give too much – so much that it negatively impacts your finances or resources. Yes, in the long run, the more good will you generate, the more you may receive if and when you need it, but you may end up never really needing it. So, using your resources to better your own immediate position is not always a bad thing. The trick, of course, is to find the right balance.

What Piercarlo and I argue is that moment-to-moment, both above and below our conscious radar, short- and long-term mechanisms are in a pitched battle to determine what we will do vis-à-vis others. Which side wins in any one instant depends on a host of factors, and understanding how the whole system works is one of the main points of the book.

Are there ways that this system functions that you think people will find surprising?

I think most surprising is the basic fact that character is always in flux. We tend to delude ourselves that character is stable, because people’’s day-to-day environments usually don’’t vary very much. But when an option or dilemma presents itself that holds very different ““pay offs”“ for the long- vs. short-term, that’’s when people may act in ways they or we would have never expected.

As we discuss in the book, simple acts like wearing colored wristbands or tapping in time to music with someone can influence the way our minds evaluate other people. In the short-term, when push comes to shove, individuals will discriminate against others who are wearing wristbands that differ in color from their own or, conversely, go out of their way to help others who were tapping in synch with them to music, as the brain interprets these colors or movements as markers of who is on “our team.”

There is something troubling in talking about these dueling systems, short-term versus long-term, because it seems to reduce people, and morality, to mechanism. Doesn’t this imply, at some level, that we are not responsible for our actions?

No, not at all. What it implies is that character isn’t solely about willpower. That doesn’t mean that we’re absolved of our responsibilities to others. Rather, it means that we have to accept that our moral behavior isn’t entirely directed by intention. However, it is usually controllable once we understand the way the system truly works.

We’re not out to dictate morality to anyone — that’s still, as it has always been, for each person to decide based on her or his beliefs, philosophy, or religion. Our goal is to show you how the system really works, and in so doing, to increase your ability to guide it in the directions you want. Once you know that your actions aren’t only influenced by willpower, you can better modify your actions by attending to, for example, what cues you expose yourself to in your environment, or what type of strategy you use (i.e., listening to your “heart” or your “mind”) to make a decision about how to treat someone.

Given your view of character, what lessons does this hold for parents? What would be examples of good ways to instill good behavior, and what would be bad ways?

I think the message here is two-fold. First, knowledge is power. Piercarlo and I would urge parents to be willing to suspend their view of how they believe character works and to examine the scientific evidence we’re putting forth.

The second part, assuming people are willing to let go of their long-held view, is that character shouldn’t be “taught” using a simple strategy of providing rules and examples. You can’t just tell Johnny to be good, or not to steal and assume that he will know how, or even be able, to do this by willpower alone. Moral education needs to be more skill-based. That is, we would advise parents to tell their kids not only what the goal is, but also how to get there — what tricks to expect their minds will engage in and what strategies they can use to keep their character moving in the direction they want. Because in the end, it’s not about “Are you a good person in general” — it’s about “Are you a good person right now.”
Permanent Address: http://www.scientificamerican.com/article.cfm?id=psychologists-put-character-under-microscope

Mary Queen of Scots defeated

May 13, 2011 · Posted in Uncategorized · Comment 

May 13, 1568:

mary_queen_of_scots_aged
At the Battle of Langside, the forces of Mary Queen of Scots are defeated by a confederacy of Scottish Protestants under James Stewart, the regent of her son, King James VI of Scotland. During the battle, which was fought out in the southern suburbs of Glasgow, a cavalry charge routed Mary’s 6,000 Catholic troops, and they fled the field. Three days later, Mary escaped to Cumberland, England, where she sought protection from Queen Elizabeth I.

In 1542, while just six days old, Mary ascended to the Scottish throne upon the death of her father, King James V. Her great-uncle was Henry VIII, the Tudor king of England. Mary’s mother sent her to be raised in the French court, and in 1558 she married the French dauphin, who became King Francis II of France in 1559 and died in 1560. After Francis’ death, Mary returned to Scotland to assume her designated role as the country’s monarch. In 1565, she married her English cousin Lord Darnley, another Tudor, which reinforced her claim to the English throne and angered Queen Elizabeth.

In 1567, Darnley was mysteriously killed in an explosion at Kirk o’ Field, and Mary’s lover, James Hepburn, the earl of Bothwell, was the key suspect. Although Bothwell was acquitted of the charge, his marriage to Mary in the same year enraged the nobility, and Mary was forced to abdicate in favor of her son by Darnley, James. In 1568, she escaped from captivity and raised a substantial army but was defeated and fled to England. Queen Elizabeth I initially welcomed Mary but was soon forced to put her cousin under house arrest after Mary became the focus of various English Catholic and Spanish plots to overthrow her.

In 1586, a major Catholic plot to murder Elizabeth was uncovered, and Mary was brought to trial, convicted for complicity, and sentenced to death. On February 8, 1587, Mary Queen of Scots was beheaded for treason at Fotheringhay Castle in England. Her son, King James VI of Scotland, calmly accepted his mother’s execution, and upon Queen Elizabeth’s death in 1603, he became James I, king of England, Scotland, and Ireland.

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