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Posted on 06/18/2010 7:13:56 PM PDT by SunkenCiv
Millions of years ago, volcanic eruptions in North America were more explosive and may have significantly affected the environment and the global climate... the remains -- deposited in layers of rocks -- of eruptions of volcanoes located on North America's northern high plains that spewed massive amounts of sulfate aerosols into the atmosphere 40 million years ago... Volcanic eruptions may have significant impacts on the environment, Bao says, citing the 1991 Mt. Pinatubo and more recent Iceland volcanic eruptions... One of the most important volcanic gases is sulfur dioxide. It is oxidized in the atmosphere and turned to sulfate aerosol... the formation of sulfate aerosol is related to atmospheric conditions at the time of a volcano's eruption. In the Nature paper, he and colleagues show that past sulfate aerosol formed in a different way than it does today, indicating a change from atmospheric conditions then to now...
(Excerpt) Read more at nsf.gov ...
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SEE??? Giant Pygmies are EVERYWHERE!!!
And in other news it was discovered that the sky is blue.
Yes, but it's not the same color of blue it used to be... in ancient past.
Just wait til Yellowstone blows, that’ll be a showstopper.
Interesting article. If I were to give the executive summary, it would be “Compared to the geological history millions of years old, nothing like the eruptions of the past compares with the last 200 years or so. We might have another big one like that in the next 100,000 years. Then again, we might not. Either way, there isn’t a damn thing we can do about it.”
Can you get grants from the Fed for this kind of study?
George A. Bush's fault...
Now I’m going to keep an eye out.
Here’s an interesting thread with lots of quality links regarding volcanoes in the GoMex . . .
Perhaps some implications given everything else . . .
http://www.abovetopsecret.com/forum/thread583641/pg1
from:
http://geology.about.com/cs/volcanology/a/aa051604a.htm
and pics of such here:
While volcanism is common under the sea, nobody dreamed that in some places, vents erupt not lava but asphalt. That’s what a 2003 research expedition found in the Gulf of Mexico on a seafloor hill the scientists named Chapopote, the Mexican Spanish name for tar. It’s the world’s first known asphalt volcano. There are more being found all the time.
The geologic setting at the site, west of the Yucatán in 3000 meters of water, is a field of salt domes called the Campeche Knolls. These tall, steep hills grow as ductile salt bodies rise into the overlying seafloor rocks; as is common around the Gulf, oil and gas leak upward with the salt.
The Asphalt Volcano Locality
The researchers, a team led by Ian MacDonald of Texas A&M University’s Corpus Christi campus, dangled a remote-controlled camera off the German ship RV Sonne to the seafloor far below. Even with this short-range visual instrument they documented one square kilometer of tar flows, some of them 20 meters across.
Besides asphalt, the expedition found places soaked with petroleum and others with cold, white layers of methane hydrate. Like cold seeps elsewhere on the world’s seafloor, all of these localities supported colonies of chemical-eating organisms. Bunches of tubeworms were found growing in and around the tar flows. Apparently something makes the asphalt attractive to life, but no one is sure yet how the biogeochemistry works.
At Chapopote the tar seems to have come out of the ground hot, but like undersea lava flows, it quickly hardens in the cold seawater. In fact it forms asphalt “aa” and “pahoehoe” just like what you find in Hawaiian basalt. In another parallel with ordinary volcanoes, the warm asphalt turns delicate icy layers of methane hydrate into bursts of free gas, just as hot rock lava causes explosions by flashing groundwater into steam — phreatomagmatic eruptions. (But I don’t know what you’d call a tar/hydrate eruption in scientific Latin.)
A Supercritical Hypothesis
In 2005 the team reported more details, and a provocative theory. Examining samples from the tar flows, the researchers found abundant small pores lined with various minerals: sulfates, chlorides and carbonates. They theorized, in the 18 October 2005 Eos, that the energy source involves a special substance: supercritical water.
Supercritical water is water at such high pressures and temperatures (300 times atmospheric pressure and 400 degrees C) that it is above the “critical point,” neither a gas nor a liquid but a searing combination. It is about one-third the density of liquid water and is a nonpolar fluid capable of dissolving hydrocarbons, unlike surface water with which oil cannot mix.
Such fluid could form deep in the crust, insulated under the seafloor sediments, just as it does beneath black smokers. If a suitable passage connected it to the surface — and a salt dome is a perfect example — then this sort of water magma could rise bearing a heavy load of dissolved minerals and hydrocarbons. As the water cools and the dissolved load precipitates, a shell of tar would form protecting the hot fluid inside, analogous to lava tubes, and the fluid would eventually reach the sea floor. There the more volatile parts of the “lava” would enter the seawater while the heavy asphalt remains.
Supercritical water could exist at depths as shallow as 2800 meters. Because the flows of Chapopote are deeper than that, the theory checks out so far. This is not the first time supercritical fluids have been suspected in the Earth: they are theorized in large mud volcanoes and in catastrophic landslides.
Are There More Asphalt Volcanoes?
Surely there’s a lot more asphalt in the Campeche Knolls and elsewhere. In fact MacDonald, in the 14 May 2004 Science, pointed out that tar flows had been photographed 200 km to the north of Chapopote in 1971. He suggested that others might locate more occurrences by doing what his team did: looking for oil slicks in satellite images of the sea surface.
Thanks Quix!
I can’t, but you could — the drawback is, you’ll have to walk naked into a live volcano as part of the initiation. Some fan of the original “Planet of the Apes” movie had the idea and got it written into the grant guidelines. Sorry.
SURE.
Thanks much for all your persistent service hereon.
You post very fascinating threads routinely.
Only if you are a Giant Pygmy.
No, really, people. I have a lot of interest in volcanic activity. I live not so far from Yellowstone, as the crow flies. Used to live right by The Craters of the Moon. My Uncle was up visiting and decided we needed to go out on the lava flow to check it out. I told him it was a bad idea. Weren't too far out, a couple of miles, when he realized what a bad idea it was. Kept giving me crap about letting him talk me into it. Figured we would need a helicopter rescue. Just so incredibly rough and tumbled. Jagged rocks. Found some really cool bands of orange and black obsidian. One was 2 feet thick. Then there are the buttes. The big southern butte is a favorite launch site for hang gliders. The other 2 are on the INL and restricted, one is full of teletowers,but if you go out when they have sheep grazing you can climb the middle one. Just tell the guys with the m-16s you are looking for lost sheep. I laugh when I see the bags of lava rock they sell for bar-b-cues. Buy it? It's everywhere. And it is always fun to go after agate nodules that have eroded out of the older rhyolite in Custer county.
Pic of The Big Southern Butte.
Pic of the Craters of the Moon. Some rough stuff to try and crawl around on.
In all fairness the subject matter is interesting. The person (can't call them a writer and it's worse if I try author) who assembled the verbiage of the article is a Giant Pygmy.
There was a particular flow out where we were farming (by the Craters) that had the nicest blue precipitate on it (blue on black). I fondly called it the blue dragon.
INTERESTING.
THANKS.
Thanks Quix.
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