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Volcano's Eruption Colors World's Sunsets
Reports of unusually fiery orange sunsets on Earth and ruby red rings around the planet Venus have popped up on the Internet in the last week.
Some skywatchers suspect that these views are being colored by the dust and gases injected into the atmosphere by the Aug. 7 eruption of Alaska's Kasatochi volcano. The skywatchers are probably right.
Kasatochi, part of the Aleutian Island chain, sent an ash plume more than 35,000 feet (10,600 meters) into the atmosphere when it erupted last month.
"This is a big ash-producing eruption," said Peter Cervelli, a research geophysicist with the United States Geological Survey at the Alaska Volcano Observatory. During a survey of the area after the eruption, Cervelli and his colleagues found ashfall deposits more than 6 inches (15 centimeters) deep at a spot 15.5 miles (25 kilometers) away from the volcano.
The fine ash injected by a volcanic eruption into the stratosphere can be carried by winds all over the world. Sulfur dioxide spewed from volcanoes can react in the atmosphere to form sulfate aerosols (aerosols are tiny particles suspended in the air). Both ash and aerosols can scatter the sun's rays, giving a sunset its apparent color.
Particles in the air normally scatter incoming sunlight — this is why the sky is blue. Sunsets (and sunrises) appear reddish because the sun's rays have more of the atmosphere to travel through, and only the longer waves at the red end of the spectrum can make it. Sulfate aerosols in particular can intensify this effect by adding more obstacles for the light to get through.
USGS researcher Melissa Pfeffer, also of the Alaska Volcano Observatory, said that the sunsets and other phenomena, which have been documented by Spaceweather.com, could indeed be related to the eruption of Kasatochi, as satellites tracking the eruption's aerosol clouds show that they have spread over the entire Northern Hemisphere.
Sightings and images of unusually colorful sunsets and other atmospheric phenomena were first reported Aug. 27.
Another colorful sight skywatchers have seen are rings of light, called Bishop's rings, around the sun and moon, which occur when the aerosols diffract the light from either source.
"That's a pretty common phenomenon after volcanic eruptions," Pfeffer said, adding that the Venusian rings could be related to stratospheric ash from Kasatochi but that she was uncertain if they were technically Bishop's rings.
Ruby red sunsets and Bishop's rings were also seen after the monstrous eruption of the Philippines' Mount Pinatubo in 1991, Pfeffer added, though that eruption was on a much larger scale than Kasatochi. In fact, the ash and aerosols that spewed from Pinatubo spread across the globe and were so pervasive that temperatures in the year after the eruption were cooler than normal. Reports of unusually fiery orange sunsets on Earth and ruby red rings around the planet Venus have popped up on the Internet in the la... more -
Volcanic eruptions wiped out ocean life 93 million years ago
University of Alberta scientists contend they have the answer to mass extinction of animals and plants 93 million years ago. The answer, research has uncovered, has been found at the bottom of the sea floor where lava fountains erupted, altering the chemistry of the sea and possibly of the atmosphere.
Undersea volcanic activity triggered a mass extinction of marine life and buried a thick mat of organic matter on the sea floor about 93 million years ago, which became a major source of oil, according to a new study.
"It certainly caused an extinction of several species in the marine environment," said University of Alberta Earth and Atmospheric Science researcher Steven Turgeon. "It wasn't as big as what killed off the dinosaurs, but it was what we call an extreme event in the Earth's history, something that doesn't happen very often."
U of A scientists Turgeon and Robert Creaser say the lava fountains that erupted altered the chemistry of the sea and possibly of the atmosphere.
"Of the big five mass extinctions in the Earth's history, most of them were some kind of impact with the planet's surface," said Turgeon. "This one is completely Earth-bound, it's strictly a natural phenomenon."
Turgeon and Creaser found specific isotope levels of the element osmium, an indicator of volcanism in seawater, in black shale-rocks containing high amounts of organic matter-drilled off the coast of South America and in the mountains of central Italy. University of Alberta scientists contend they have the answer to mass extinction of animals and plants 93 million years ago. The answe... more -
The Human Cost of Ten Devastating Earthquakes: Priceless
Earthquakes are caused by the shifting of tectonic plates on the earth's surface. When these plates shift, the ground can move violently. Earthquakes have changed the terrain of our planet since the beginning of time. Unfortunately, there has been a high human cost to this major force of nature. Earthquakes are caused by the shifting of tectonic plates on the earth's surface. When these plates shift, the ground can move vi... more
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Residents fret in shadow of Chile's Llaima volcano
Living in the shadow of Chile's sporadically erupting, snow-capped Llaima volcano, one of South America's most active, local residents like Eduardo Mendoza are paying a heavy price.
Evacuated from the ski station where he works after the government imposed a red alert when Llaima began spewing lava earlier this month, Mendoza and dozens like him have lost their livelihoods and are having trouble feeding their families.
This is the second ski season in a row interrupted by the volcano, which towers near Chile's lake region about 435 miles
south of the capital Santiago.
"People can't go to work because of the danger," he said, a cloud engulfing the majestic volcano behind him, black scars on its white slopes betraying where lava has flowed and cooled.
"Our source of work has been stopped and we depend on it to sustain our families. We can't go on like this," he added, showing a video clip on his mobile phone of the volcano spewing a jet of hot pyroclastic rock 1,300 feet into the air before dawn on Thursday.
That flurry of activity in turn came a week after lava spewed down one of its sides.
Aside from hot rock and gas, or lava flows, that have emanated from the crater, another major worry is that snow on the volcano's sides could melt and that a nearby river could overflow and flood nearby communities.
The volcano erupted violently on New Year's Day, forcing the temporary evacuation of some tourists and residents from the surrounding Conguillio National Park. It belched ash and lava in February. Much of the park is off limits again.
The government this month ordered a 9-mile "red zone" around the 10,253-foot (3,124 meter)-high volcano, and has now evacuated around 60 people from nearby.
FUTURE ACTIVITY
Experts say there is no knowing how the volcano, the second to erupt in Chile in as many months, will continue to behave.
"The activity is going up and down very fast," said Hugo Moreno, a geologist and volcano expert with state mining and geology service Sernageomin, who is based in the town of Melipeuco, on the fringe of the exclusion zone.
"It is oscillating, so it is very difficult to make a medium-term forecast," he added. "It will most likely continue to oscillate, until it stabilizes at some point."
Llaima's current eruptive cycle began in May last year. Cycles have lasted anything from one minute to three years or more, Moreno said.
In the sleepy town of Cherquenco, 11 miles from the base of the volcano, Agriculture Minister Marigen Hornkohl sought to reassure worried farmers.
They complain are only allowed into the exclusion area to tend to their animals two hours a day, and are worried they'll die, be stolen, or be eaten by puma.
"We have to take this one minute at a time," Hornkohl told residents and evacuees assembled in the rear of the local fire station. "Now, when we want to be able to go home, the worst thing we can do is to take the wrong decisions," she said.
LLaima's renewed activity comes after Chaiten volcano, 760 miles south of Santiago in Chilean Patagonia, erupted on May 2 for the first time in thousands of years, spewing ash, gas and molten rock.
Ash from Chaiten, which initially soared 20 miles into the stratosphere, swelled rivers in the area and caused floods that damaged dozens of wooden houses, sweeping some off their foundations.
Chile's chain of some 2,000 volcanoes is the world's second-largest after Indonesia's. Around 50 to 60 are recorded to have erupted, while 500 are deemed potentially active. Living in the shadow of Chile's sporadically erupting, snow-capped Llaima volcano, one of South America's most active, local... more -
Chaiten Volcano active since May 6th
Chaiten Volcano in Chile continues to erupt, after its recent eruption on May 6th, - its first activity in over 9,000 years. (12 crazy ass photos in total) Chaiten Volcano in Chile continues to erupt, after its recent eruption on May 6th, - its first activity in over 9,000 years. (12 crazy... more
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Helium isotopes point to the best sources of geothermal energy
TEMPE, Ariz. With fossil fuel sources depleting and global warming on the rise, exploring alternative means of power for humans is a necessary reality. Now, looking to the sky, relying on the wind or harnessing water power are not the only remaining options. Deep within Earth is an untapped source of energy: geothermal energy.
It has been estimated that within the continental United States, there is a sizable resource of accessible geothermal energy about 3,000 times the current annual U.S. consumption.
Now, research by van Soest and B. Mack Kennedy at Lawrence Berkeley National Laboratory reveals that geothermal exploration doesnt have to be high-priced.
Pictured:Wairakei geothermal power station, New Zealand TEMPE, Ariz. With fossil fuel sources depleting and global warming on the rise, exploring alternative means of power for humans is a... more
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