 |
||
| · join · view topics · view or post blog · bookmark · post new topic · | ||
Posted on 06/25/2008 11:32:36 AM PDT by decimon
International expedition discovers gigantic volcanic eruption in the Arctic Ocean
An international team of researchers was able to provide evidence of explosive volcanism in the deeps of the ice-covered Arctic Ocean for the first time. Researchers from an expedition to the Gakkel Ridge, led by the American Woods Hole Oceanographic Institution (WHOI), report in the current issue of the journal Nature that they discovered, with a specially developed camera, extensive layers of volcanic ash on the seafloor, which indicates a gigantic volcanic eruption.
"Explosive volcanic eruptions on land are nothing unusual and pose a great threat for whole areas," explains Dr Vera Schlindwein of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association. She participated in the expedition as a geophysicist and has been, together with her team, examining the earthquake activity of the Arctic Ocean for many years. "The Vesuvius erupted in 79 AD and buried thriving Pompeii under a layer of ash and pumice. Far away in the Arctic Ocean, at 85° N 85° E, a similarly violent volcanic eruption happened almost undetected in 1999 – in this case, however, under a water layer of 4,000 m thickness." So far, researchers have assumed that explosive volcanism cannot happen in water depths exceeding 3 kilometres because of high ambient pressure. "These are the first pyroclastic deposits we've ever found in such deep water, at oppressive pressures that inhibit the formation of steam, and many people thought this was not possible," says Robert Reves-Sohn, staff member of the WHOI and lead scientist of the expedition carried out on the Swedish icebreaker Oden in 2007.
A major part of Earth's volcanism happens at the so-called mid-ocean ridges and, therefore, completely undetected on the seafloor. There, the continental plates drift apart; liquid magma intrudes into the gap and constantly forms new seafloor through countless volcanic eruptions. Accompanied by smaller earthquakes, which go unregistered on land, lava flows onto the seafloor. These unspectacular eruptions usually last for only a few days or weeks.
The Gakkel Ridge in the Arctic Ocean spreads so slowly at 6-14 mm/year, that current theories considered volcanism unlikely - until a series of 300 strong earthquakes over a period of eight months indicated an eruption at 85° N 85° E in 4 kilometres water depth in 1999. Scientists of the Alfred Wegener Institute became aware of this earthquake swarm and reported about its unusual properties in the periodical EOS in the year 2000.
Vera Schlindwein and her junior research group are closely examining the earthquake activity of these ultraslow-spreading ridges since 2006. "The Gakkel Ridge is covered with sea-ice the whole year. To detect little earthquakes, which accompany geological processes, we have to deploy our seismometers on drifting ice floes." This unusual measuring method proved highly successful: in a first test in the summer 2001 – during the "Arctic Mid-Ocean Ridge Expedition (AMORE)" on the research icebreaker Polarstern – the seismometers recorded explosive sounds by the minute, which originated from the seafloor of the volcanic region. "This was a rare and random recording of a submarine eruption in close proximity," says Schlindwein. "I postulated in 2001 that the volcano is still active. However, it seemed highly improbable to me that the recorded sounds originated from an explosive volcanic eruption, because of the water depth of 4 kilometres."
The scientist regards the matter differently after her participation in the Oden-Expedition 2007, during which systematic earthquake measurements were taken by Schlindwein's team in the active volcanic region: "Our endeavours now concentrate on reconstructing and understanding the explosive volcanic episodes from 1999 and 2001 by means of the accompanying earthquakes. We want to know, which geological features led to a gas pressure so high that it even enabled an explosive eruption in these water depths." Like Robert Reves-Sohn, she presumes that explosive eruptions are far more common in the scarcely explored ultraslow-spreading ridges than presumed so far.
###
Notes for Editors:
Your contact person at the Alfred Wegener Institute is Dr Vera Schlindwein (phone: +49 471 4831-1943, email: Vera.Schlindwein@awi.de). Your contact person in the public relations department is Ralf Roechert (phone: +49/471/4831-1680; email: ralf.roechert@awi.de). In case of publication please send a copy.
Under http://www.awi.de/en/news/images_video_audio/embargoed_photos/ you can find printable images until the end of the embargo, thereafter as part of the press release under http://www.awi.de.
The Alfred Wegener Institute carries out research in the Arctic and Antarctic as well as in the high and mid latitude oceans. The institute coordinates German polar research and makes available to international science important infrastructure, e.g. the research icebreaker "Polarstern" and research stations in the Arctic and Antarctic. AWI is one of 15 research centres within the Helmholtz-Association, Germany's largest scientific organization.
Rove, Bush and Haliburton are behind this! No doubt!
Gee, do you think they will put 2 + 2 together and realize that this was probably one of the major reasons for a decrease in the ice-pack in the Artic?
Wonder how long before someone blames this on global warming.
Aught oh, alGore blames Gawd for deceiving folks about global warming by placing Volcano's under the polar regions.
Hey Frosty!
Surfs Up. Jump in the hot tub!
It’s Global Squeezing.
The combined weight of mankind is squeezing the earth, forcing lava through volcanos underneath the artic. Which of course will melt the artic ice. We all must diet now.
On a side note, I passed by an Ethiopian restaurant in Nashville yesterday. And as I pondered what kind of foods Ethiopians eat it dawned on me that the portions were probably very very very small.
I’m no scientist but based on my experiements, Ice will actually melt if heat is applied to it
|
||
| · join · view topics · view or post blog · bookmark · post new topic · | ||
Probably arugula. Arugula is the in herb.
“On a side note, I passed by an Ethiopian restaurant in Nashville yesterday. And as I pondered what kind of foods Ethiopians eat it dawned on me that the portions were probably very very very small.”
Actually, Ethiopian food is very tasty and fun to eat too.
The food is served on a big flat piece of spongy bread - I forget what it’s called. Little piles of spiced chicken, beef, lamb, beans, veggies, etc., are placed on the big open bread stuff.
Each person also has a roll of this bread stuff, rips off a piece, then uses it to pick up some of the food in piles, mixing the various flavors and spices in the bread. Each bite, therefore is different.
When finished, you can eat the big open bread as well with many of the flavors mixed in.
The food is spicy, no so much as, say Indian food, but all in all, it’s certainly worth a try, especially if you are looking for “CHANGE” in your dining experiences.
I’d recommend Ethiopian food for a pleasant meal and a good time with friends.
Oh yes, I had an Ethiopian meal once. Quite tasty, all right. The bread reminded me of a big grey pancake. I forget what they call it, but it is made out of a grain called teff.
Historically, mariners had seen discoloured water in the area and scientists knew ash from underwater volanoes can discolour the water above them.
To confirm their suspicions, Domack and his colleagues used four types of instruments:
A video camera recorded the bottom two metres of the sea floor behind the ship. As expected for an active volcano, there were patches with no underwater life. A basket dredged the sea floor, recovering bits of bedrock that were clearly volcanic based on their mineralogy and magnetic properties. Acoustic measurements showed what appeared to a rising column of bubbles. Sensitive temperature probes showed slight variations at the edges, suggesting geothermal heating...
Thanks for the info.
I don’t know but I knew a guy who used to teach military special forces how to live off the land. He said boiled porcupine was probably the worst thing he ever ate.
I’ve been to that restaurant. It’s right down the street from Knoshville Katz Kosher Deli.
“Gee, do you think they will put 2 + 2 together and realize that this was probably one of the major reasons for a decrease in the ice-pack in the Artic?”
The Arctic is so vast that I doubt a single eruption (even a large one) would have that great an impact on Arctic water temperatures. And it happened nine years ago. But it is interesting in that once again it shows we don`t know all there is to know.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.