Update: Volcanic activity and discoveries

(News & Editorial/Update: Volcanic activity and discoveries)

volcanic eruption

A.  Volcanoes
Wunderground, Excerpt pasted from: http://www.wunderground.com/climate/volcanoes.asp

“The sun was dark and its darkness lasted for eighteen months; each day it shone for about four hours; and still this light was only a feeble shadow; the fruits did not ripen and the wine tasted like sour grapes.” As this ‘Michael the Syrian’ quote regarding the weather of 536 A.D. demonstrates, a climate catastrophe that blots out the sun can really spoil your day.

‘Procopius of Caesarea’ remarked: “During this year [536 A.D.] a most dread portent took place. For the sun gave forth its light without brightness. and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear.”

Many documents from 535 – 536 A.D.–the time of King Arthur in Britain–speak of the terrible “dry fog” or cloud of dust that obscured the sun, causing widespread crop failures in Europe, and summer frosts, drought, and famine in China. Tree ring studies in Europe confirm several years of very poor growth around that time, and ice cores from Greenland and Antarctica show highly elevated levels of atmospheric sulfuric acid dust existed.

Though some scientists believe the climate calamity of 535-536 A.D. was due to a comet or asteroid hitting the Earth, it is widely thought that the event was probably caused by the most massive volcanic eruption of the past 1500 years. This eruption threw so much sulfur dioxide (SO2) gas into the stratosphere that a “Volcanic Winter” resulted. Sulfur dioxide reacts with water to form sulfuric acid droplets (aerosol particles), which are highly reflective and reduce the amount of incoming sunlight. The potential eruption that led to the 535 – 536 A.D. climate calamity would have likely been a magnitude 7 event on the Volcanic Explosivity Index (VEI)–a “super colossal” eruption that one can expect to occur only once every 1000 years. The Volcanic Explosivity Index is a logarithmic scale like the Richter scale used to rate earthquakes, so a magnitude 7 eruption would eject ten times more material than the two largest eruptions of the past century–the magnitude 6 eruptions of Mt. Pinatubo in the Philippines (1991) and Novarupta in Alaska (1912).

B.  Alaska Volcano Observatory is Having Busiest Volcano Year to Date
17 June 2014, KDLG.org, (Public radio for Alaska’s bristol Bay), By Luke Brummer
Pasted from: http://kdlg.org/post/alaska-volcano-observatory-having-busiest-volcano-year-date

Scientists at the Alaska Volcano Observatory are paying extra close attention lately due to high seismic activity at five volcanoes running all along the Aleutian Chain. Many of the volcanoes have recently sprung back to life, and others have just continued their normal eruptions. John Power is the Scientist-in-charge at AVO. He says a few recent explosions and heightened unrest have led to the busiest time since the inception of the state’s observatory.

It is the busiest time that we have had in terms of Alaska Volcanoes. As long has AVO has been around in 27 years. We do have five that are at alert levels or color codes.

Vol Aleutian chain

A screen capture of active Alaska Volcanoes as of June 17, 2014.

Power says the most active volcano recently has been Pavlof, which has erupted continuously since the May 31st. He says it has had some explosive activity and lava flows along the Northwest side. It currently has a “watch” Alert Level and an “orange” Aviation Color Code. The Shishaldin Vocano is the other volcano with a “watch” Alert Level, and “orange” Aviation Color Code. Power says the volcano has experienced continuing low level eruptive activity, and its conditions form its recognizable outward appearance.

Shishaldin is one of the ones that you would say looks like a volcano. There’s a big summit crater, and we’re having magma, low level magma, extrusions have been observed down inside the summit crater. It’s been a very effusive eruption, we would call it. It hasn’t put out big ash cloud or had explosions. It’s just been lava oozing out in the inside of this crater if you will.

Power says the Cleveland Volcano has clearly been the most active volcano over the last ten years. On June 5th, AVO picked up two explosions from seismic monitoring stations and infrasonic data. Power says the observatory primarily monitors the volcano via satellite data because of its remote location, but from what they can tell conditions have stayed the same. The Semisopochnoi Volcano is the most remote of the 5 active volcanos. It’s more than 1,000 miles west of the Pavlof Volcano near the island of Amchitka. Powers says the volcano has not had any eruptions or warm ground, but AVO raised its Aviation Color Code to “yellow” due to a sequence of elevated earthquake activity. The Veniaminof Volcano is also showing volcanic activity. It’s located in the Alaska Peninsula National Wildlife Refuge. Power says it had a sizeable eruption last summer and seismic activity has continued throughout the year causing AVO to continue monitoring conditions at the volcano.

Every time we look at it and we think it’s time to cancel these advisories it does a little bit more, and we’re continuing to watch it just as closely as we can.
You can follow the activity at all of Alaska’s active volcanos on the website of the Alaska Volcano Observatory.

C. Risk of supervolcano eruption big enough to ‘affect the world’ far greater than thought, scientists say
27 June 2014, The Independent, by __
Pasted from: http://www.independent.co.uk/news/science/risk-of-supervolcano-eruption-big-enough-to-affect-the-world-far-greater-than-thought-say-scientists-9040073.html

The eruption of a “supervolcano” hundreds of times more powerful than conventional volcanoes – with the potential to wipe out civilisation as we know it – is more likely than previously thought, a study has found.

An analysis of the molten rock within the dormant supervolcano beneath Yellowstone National Park in the United States has revealed that an eruption is possible without any external trigger, scientists said.

Scientists previously believed many supervolcanic eruptions needed earthquakes to break open the Earth’s crust so magma could escape. But new research suggests that this can happen as a result of the build-up of pressure.

Supervolcanoes represent the second most globally cataclysmic event – next to an asteroid strike – and they have been responsible in the past for mass extinctions, long-term changes to the climate and shorter-term “volcanic winters” caused  by volcanic ash cutting out the sunlight.

The last known supervolcanic eruption was believed to have occurred about 70,000 years ago at the site today of Lake Toba in Sumatra, Indonesia. It caused a volcanic winter that blocked out the sun for between six to eight years, and resulted in a period of global cooling lasting a thousand years.

A supervolcano under Yellowstone Park in Wyoming last erupted about 600,000 years ago, sending more than 1,000 cubic kilometres of ash and lava into the atmosphere – about 100 times more than the Mount Pinatubo eruption in the Philippines in 1982, which caused a noticeable period of global cooling.

Following Pinatubo’s eruption, the global average temperature fell by about 0.4C for several months. Scientists predict that a supervolcanic eruption would cause average global temperatures to fall by about 10C for a decade – changing life on earth.

Scientists have analysed magma from the Yellowstone caldera, a 55-mile-wide underground cavern containing between 200 and 600 cubic kilometres of molten rock, to see how it responds to changes in pressure and temperature.

Using a powerful X-ray source at the European Synchrotron Radiation Facility in Grenoble, France, the researchers found that the density of the magma decreased significantly at the high temperatures and pressures experienced underground.

Density variations between magma and the rock surrounding it means that the lava within the supervolcano’s caldera can produce big enough forces to break through the earth’s crust, allowing the molten rock and ash to erupt from the surface, the scientists said.

“The difference in density between the molten magma in the caldera and the surrounding rock is big enough to drive the magma from the chamber to the surface,” said Jean-Philippe Perrillat of the National Centre for Scientific Research in Grenoble.

“The effect is like the extra buoyancy of a football when it is filled with air underwater, which forces it to the surface because of the denser water around it,” Dr Perrillat said.

“If the volume of magma is big enough, it should come to the surface and explode like a champagne bottle being uncorked.”

The study, published in the journal Nature Geoscience, was possible because the X-ray machine at Grenoble was able to take accurate density measurements at temperatures of up to 1,700C and pressures 36,000 times greater than normal atmospheric pressure.

“The results reveal that if the magma chamber is big enough, the overpressure caused by differences in density alone are sufficient to penetrate the crust above and initiate an eruption,” said Professor Carmen Sanchez-Valle of the Swiss Federal Institute of Technology (ETH) in Zurich, who led the study.

Preventing a supervolcanic eruption is not possible, but scientists are currently trying to devise methods of monitoring the pressure of underground magma in order to predict whether one is imminent.

Dr Perrillat said there are no known supervolcanoes that are in danger of erupting in the foreseeable future, and it would take at least a decade or so for the magma pressure within a caldera to build up to a point where an eruption is likely.

D.  Newly-discovered active volcano could erupt underneath ice in Antarctica and add to effects of global warming
12 May 2014, The Extinct Protocol, by  Lucy Crossley of DailMail-MailOnline, UK
Pasted from: http://theextinctionprotocol.wordpress.com/2014/05/12/newly-discovered-active-volcano-could-erupt-underneath-ice-in-antarctica-and-add-to-effects-of-global-warming/

Vol antarctica

May 2014ANTARCTICA – Antarctic ice sheet is being threatened by an undersea volcano. Antarctica’s ice sheets may face a far more imminent threat than climate change: scientists have found a new volcano forming a mile under the ice, which is threatening a full eruption. The volcano appears to be a part of much larger system that is generating earthquakes and releasing heat into the ice above. Volcanic activity was discovered around 30 miles from Antarctica’s highest volcano, Mount Sidley, and although an eruption would be unlikely to breach the ice – the accompanying heat could have an effect on the landscape. Even a sub-glacial eruption would still be able to melt ice, creating huge amounts of water which could flow beneath the ice and towards the sea – hastening the flow of the overlying ice and potentially speed up the rate of ice sheet loss. “Numerous volcanoes exist in Marie Byrd Land, a highland region of West Antarctica,” said Amanda Lough, of Washington University in St Louis in the team’s paper on the subject, published in the Nature Geoscience journal.

“High heat flow through the crust in this region may influence the stability of the West Antarctic Ice Sheet.” The Antarctic ice sheet is one of the Earth’s two polar ice caps and covers an area of 5.4 million square miles – around 98 percent of the continent, making it the largest single mass of ice on earth. Although scientists have suggested that sea ice around the continent is increasing, land ice appears to be decreasing and the area is very sensitive to global warming.  Seismologists had set up two crossing lines of seismographs across Marie Byrd Land in 2010 – the first time such instruments able to withstand the cold temperatures year-round had been used. –Daily Mail

vol ring of fire


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