Environment Clean Generations: eruption

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Which Volcanoes Will Erupt This Year?

After 50 days of silence, Sicily’s Mt. Etna rang in the New Year with a new eruption the morning of January 5. Plumes of black ash and lava rose 5,000 meters high in a style reminiscent of the volcano’s 18 eruptions last year.

Etna was not the first volcano to wake up in the first days of 2012 (scroll down for our Top Five New Eruptions of 2012), but it was certainly the most spectacular. Etna's snow-capped slopes enhanced the beauty of these latest fireworks; the snow also made the eruption smokier than some.

Europe’s tallest and most active volcano, Etna got its explosive start about half a million years ago as a series of submarine eruptions off the ancient coastline of Sicily. The restless mountain rose to its current grandeur via the accumulation of layer upon layer of erupted debris.

A similar process is just getting underway off the coast of El Hierro in Spain's Canary Islands, where ongoing eruptions are just beginning to break the ocean surface:

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This past week’s report from the Smithsonian/USGS Global Volcanism Program listed nine ongoing eruptions from last year, including El Hierro and Kilauea, on the Big Island of Hawaii.

Note that Germany's Laacher See was NOT on the official list of new activity, despite a recent Daily Mail story suggesting otherwise.

TOP 5 NEW ERUPTIONS OF 2012

Etna (Italy): Plumes of black ash and lava began erupting in the early morning hours of January 5.
Lewotolo (Indonesia): Earthquakes intensified on January 2, following a month of white plumes rising 50 to 250 meters above the mountain’s summit; local officials raised the alert level from 1 to 3 in response to this change in activity.
Tungurahua (Ecuador): A plume of gas and steam plume rose 200 meters above the crater on January 3. Explosions the previous week blanketed nearby villages with ash 2 to 4 millimeters deep.
Galeras (Colombia): A webcam showed gas emissions, with steam rising from three separate craters.
Callaqui (Chile): A pilot reported an ash plume above the volcano on January 2, but scientists could not confirm the presence of ash in satellite imagery under clear skies.

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Ancient Source of Earth

The world's largest volcanic eruptions appear to be derived from a reservoir of magma at least 4.5 billion years old. The magma represents a remnant of the composition of the early Earth. The findings suggest that the Earth's overall mineral composition is different than previously thought.

Researchers believe that several of the largest volcanic eruptions in Earth's history were fueled by magma from a primitive reservoir in the mantle that has remained unchanged for 4.5 billion years, a remnant of the material that formed the early Earth.

Punctuating the last 250 million years, these staggering eruptions sometimes lasted several million years and were so large that a single event could double the total amount of magma on the Earth's surface.

The most recent of the resulting formations (called flood basalts) is found on Baffin Island in Canada and West Greenland, created by eruptions 62 million years ago. Samples from here gave researchers the first indication that the ancient mantle reservoir existed.

In a report published last year, researchers found unexpected element concentrations and isotope ratios that matched what is predicted for the primitive mantle -- the homogeneous matter that surrounded the Earth's newly-formed metal core before the mantle cooled enough to separate the crust from the modern mantle. In the new report, published Wednesday in Nature, the researchers find that world's other largest eruptions tapped this same reservoir.

"We decided to look at other flood basalts." said Matthew Jackson of Boston University who authored the new study with Richard Carlson of the Carnegie Institution of Washington.

They started with the biggest one, the Ontong Java plateau, a Pacific Ocean, undersea plateau the size of Alaska, 20 miles thick and as big as the other flood basalts combined. They studied its isotope ratios and element concentrations, as with the previous case.

"It had a lot of the same characteristics as the Baffin Island ones that we looked at last year" he said. They looked at four others around the world, with similar results.

Taken together, "The world's largest volcanic events in the last 250 million years all seem to have compositions that are consistent with sampling an early Earth reservoir," Jackson said.

The findings make sense, he notes, because the undisturbed, never-melted primitive mantle material would have retained high concentrations of radioactive elements to provide a lot of heat, as well as relatively high levels of easily melted materials, compared to already-depleted mantle reservoirs.

"Together these are the perfect recipe for generating enormous quantities of melt," Jackson said.

Recent work by others indicates that the largest volcanic events all erupted over one of two "superplumes" in the mantle, one under Africa and one in the South Pacific. It may be that these represent the locations of primitive mantle reservoirs, Jackson noted.

The findings also raise questions about what the Earth is made of, Jackson said. "We've always thought that Earth's primitive mantle would be the same as chondrites," carbon-containing meteorites thought to contain material formed in the early solar system. "People always thought the earth was just an agglomeration of chondrites."

But the new findings suggest Earth's early mantle does not have a chondritic origin. "If the Earth is not chondritic, we developed a very specific hypothesis for what its composition would be. Isotope compositions in Baffin Island lavas perfectly match that composition."

"If it is true, it is going to be a big paradigm shift," said Mukul Sharma of Dartmouth College in Hanover, NH. "All textbooks in geochemistry will have to be revised," Still, he added, other types of evidence need to be found before this can be confirmed.

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Huge Eruption Seen On Sun

A solar flare created a spectacular eruption on June 7 (pictured).

A mushroom of cooled plasma popped like a pimple and rained onto the surface of the sun yesterday—shooting perhaps the largest amount of solar material into space ever seen, scientists say.

The solar flare—an unusually bright spot on the sun—wasn't surprising as a "moderate" event. Space observatories in the past year recorded about 70 such solar flares, each roughly ten times weaker than "extreme" flares, of which only two have occurred since 2007.

Instead, what shocked scientists was the unusual amount of material that lofted up, expanded, and fell back down over roughly half the surface area of the sun. The event's simultaneous launch of particles into space is called a coronal mass ejection (CME).

"This totally caught us by surprise. There wasn't much going on with this spot, but as it came from behind the sun, all of the sudden there was a flare and huge ejection of particles," said astrophysicist Phillip Chamberlin of NASA's Solar Dynamics Observatory (SDO), one of several spacecraft that recorded the event.

"We've never seen a CME this enormous."

Chamberlin said it will take some time to calculate the energy and mass of electrons and protons blasted into space. But he noted the volume occupied a space hundreds of times bigger than a single Earth.

The ejection of particles burst from the right limb of the sun and sprayed into space, so the blast will miss Earth—though the explosion may brighten auroras near Earth's poles, Chamberlin said.

Here are some pictures of auroras generated by the solar flare.

But he warned space-weather experts are concerned about future solar events.

The sun's 11-year cycle of activity, driven by tangled surface magnetic fields, will hit its maximum in late 2013 or early 2014. Magnetic messiness will peak around that time and prompt nasty solar storms.

"We'll probably see [extreme] flares every couple of months instead of years," Chamberlin said.

If one of these powerful flares—and its coronal mass ejection—faces Earth, the particles will pound satellite components with charged particles, short some out, and potentially cripple them.

On the planet's surface, extra currents of solar particles drive extra electric current through power lines and heat them up.

A solar storm in 1859, for example, caused telegraph lines to burst into flames. Power companies distribute loads to avoid such a disaster, but energetic solar storms could still blow transformers and lead to power outages, especially during heat waves like the one sweeping the eastern U.S. this week."Despite great countermeasures, the power grid is still vulnerable. We could be in for some serious problems," Chamberlin said.