Science Scanner: What Triggers Devastating Supervolcanoes

Posted October 12th, 2011 at 7:38 pm (UTC-4)
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The Mt. St. Helens eruption of May 18, 1980, sent volcanic ash, steam, water, and debris to a height of 60,000 feet. About two-thirds of a cubic mile of material was ejected. In comparison, the Toba supereruption, one of the Earth's largest known eruptions, was ~1000 times more (Photo: Washington State Department of Natural Resources)

The Mt. St. Helens eruption of May 18, 1980, sent volcanic ash, steam, water, and debris to a height of 60,000 feet. About two-thirds of a cubic mile of material was ejected. In comparison, the Toba super eruption, one of the Earth's largest known eruptions, spewed 1,000 times more material. (Washington State Department of Natural Resources)

A volcanic super eruption, which occurs about every 100,000 years,  is a cataclysmic natural event, blowing out an incredible amount of debris and ash,  devastating the environment and disrupting the world’s climate for years, possibly causing mass extinctions.

While scientists continuously monitor several super volcanoes around the world, they don’t know what actually triggers these violent explosions. Now, a new model of volcanic super eruptions shows these massive eruptions could be caused by a combination of magma chamber geometry and temperature.

Researchers at Oregon State University say the creation of a halo of flexible rock, which forms around the magma chamber, allows the pressure – built up over tens of thousands of years – to raise the roof above the magma chamber.  Eventually faults from above trigger the collapse of the caldera, which leads to its subsequent eruption.

“You can compare it to cracks forming on the top of baking bread as it expands, as the magma chamber pressurizes at depth, cracks form at the surface to accommodate the doming and expansion,” says lead author Patricia Gregg, a post-doctoral researcher. “Eventually, the cracks grow in size and propagate downward toward the magma chamber.”

Findings of this research were presented at the annual meeting of the Geological Society of America in Minneapolis, Minn.

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Einstein’s theory of relativity isn’t moot yet

Albert Einstein (circa 1921) (Photo: wikipedia)

Albert Einstein circa 1921 (wikipedia)

Officials from three of the world’s major physics labs express doubt about recent findings by European scientists who claim to have recorded subatomic particles moving faster than the speed of light.

Back in September, scientists used a particle accelerator – provided by the European Organization for Nuclear Research (CERN) – to fire a neutrino beam from a lab near Geneva to another in Italy. They say it traveled 60 nanoseconds faster than the speed of light. If true, that would disprove Einstein’s theory of relativity, which suggests nothing travels faster than light.

The three officials – Rolf Heuer of CERN, Pier Oddone of Fermi National Accelerator Laboratory (Fermilab in the U.S.) and Atsuto Suzuki of High Energy Accelerator Research Organization (KEK) in Japan – also said they share a growing conviction that the Higgs boson, a particle which explains why matter has mass, will be found or ruled out within 12 months.

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Sleep critical to adolescent’s developing brain

(Photo: - (C) 2007 Jupiterimages)

 ( (C) 2007 Jupiterimages)

Lack of sleep during adolescence could lead to more than slow-moving, sleepy teens, it could also have a lasting  impact on how the brain is wired.

We already know that adolescence is a crucial and sensitive period of development when the brain changes dramatically. During a person’s early teen years, the brain undergoes a massive rewiring of nerve circuits.

Experimenting with adolescent mice, researchers at the University of Wisconsin-Madison found that short-term sleep restriction in their test subjects prevented the balanced growth and depletion of brain synapses, which are the connections between nerve cells where communication occurs.

The researchers are now looking into what happens to the young brain when there is a chronic sleep restriction, a condition many adolescents often experience.

Study leader Dr. Chiara Cirelli says she can’t predict the outcome of the studies which are already under way. “It could be that the changes are benign, temporary and reversible. Or there could be lasting consequences for brain maturation and functioning.”

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Mooning over asteroids

Artist rendition of Minvera (from University of Tennessee, Knoxville)

Artist rendition of Minvera (University of Tennessee, Knoxville)

Most of us know that a number of planets have one or more moons orbiting them, but it might surprise you to learn that some asteroids have them, too. In fact, Joshua Emery at the University of Tennessee, Knoxville says about 20 percent of asteroids do.

Emery, a member of an international team planetary astronomers, focused his research on the triple asteroid Minerva, located in the main-asteroid-belt, which contains most of our solar system’s asteroids. Minverva is known to possess two moons.

“Minerva was thought to be a pretty typical, unremarkable asteroid until we discovered its two moons,” Emery says. “Now, interest in this system has grown. And through a lot of new observations, from both ground-based and space-based telescopes, we have developed a much more detailed understanding of Minerva and its moons.”

Emery and his team believe the discovery of moons around asteroids is important because it can provide clues to the asteroid’s formation.

“All other large main-belt asteroids with one or more moons are very porous,” says Emery. “Such high porosity strongly suggests that they are piles of rubble held together by gravity rather than solid rocks.”

The results of the group’s findings were released at the EPSC-DPS meeting in Nantes, France.

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Rick Pantaleo
Rick Pantaleo maintains the Science World blog and writes stories for VOA’s web and radio on a variety of science, technology and health topics. He also occasionally appears on various VOA programs to talk about the latest scientific news. Rick joined VOA in 1992 after a 20 year career in commercial broadcasting.

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