Volcanoes erupting beneath Arctic ice

[Abdul Alhazred]

Volcanoes erupting beneath Arctic ice (MSNBC)

Quote:

Seafloor unexpectedly active, but scientists see no connection to ice loss

New evidence deep beneath the Arctic ice suggests that a series of underwater volcanoes have erupted in violent explosions in the past decade.

Hidden 2.5 miles (4 kilometers) beneath the Arctic surface, the volcanoes can range up to more than a mile (2 kilometers) in diameter and a few hundred yards (meters) tall. They formed along the Gakkel Ridge, a lengthy crack in the ocean crust where two rocky plates are spreading apart, pulling new melted rock to the surface.

Until now, scientists thought undersea volcanoes only dribbled lava from cracks in the seafloor. The extreme pressure from the overlying water makes it difficult for gas and magma to blast outward.

...

With news this week that polar ice is melting dramatically, underwater Arctic pyrotechnics might seem like a logical smoking gun. Scientists don't see any significant connection, however.

"We don't believe the volcanoes had much effect on the overlying ice," Reeves-Sohn told LiveScience, "but they seem to have had a major impact on the overlying water column."

The eruptions discharge large amounts of carbon dioxide, helium, trace metals and heat into the water over long distances, he said.

...

It occurs to me that even if the volcanic heat isn't melting the ice directly, the CO₂ emissions would be contributing to ... whatever it is that CO₂ emissions contribute to.

So we have to reduce our own emissions even more to make up for it?

Anyone have some figures on how much CO₂ from volcanoes versus burning fossils?

[Abdul Alhazred]

Hmm.

According to this, volcanoes don't contribute much:

http://volcano.und.edu/vwdocs/Gases/man.html

[rjh01]

The amount of co2 given off over any one period would be about the same as any other equal period. There is no evidence that the amount has increased recently.

[GreyICE]

Originally Posted by Abdul Alhazred

Hmm.

According to this, volcanoes don't contribute much:

http://volcano.und.edu/vwdocs/Gases/man.html

Given that volcanos aren't actually burning, but expelling hot molten rock from the earth's core, there's simply no way they're a significant source of CO2. They're not heated by combustion.

Oh and 2.5 MILES? The heat capacity of water is enormous. There's no way a volcano could make a serious temperature change in 2.5 miles of ocean, unless it was enormous beyond all belief (We're talking new islands forming sort of enormous)

[mhaze]

http://en.wikipedia.org/wiki/Lake_Nyos

Strange things happen deep down. ..

[GreyICE]

Originally Posted by mhaze

http://en.wikipedia.org/wiki/Lake_Nyos

Strange things happen deep down. ..

Of course the outgassing that killed so many people represents less than 1/10th of 1% of the CO2 we release each year, but yes, totally must be the source.

[BenBurch]

Vulcanism occurs in all eras and in about the same amounts except when continental plates collide as they did in the Deccan Traps era. One or two extinctions may have been due to vulcanism and its secondary effects reducing the amount of oxygen in the air.

But the amount of heat from ordinary subsea vulcanism is negligible and the amount of CO2 is already a part of the background.

Nice straw man too, if he only had a brain!

[mhaze]

Originally Posted by GreyICE

Of course the outgassing that killed so many people represents less than 1/10th of 1% of the CO2 we release each year, but yes, totally must be the source.

on August 21, 1986, a limnic eruption occurred at Lake Nyos which triggered the sudden release of about 1.6 million tonnes of CO2. The gas spilled over the northern lip of the lake into a valley running roughly east-west from Cha to Subum, and then rushed down two valleys branching off it to the north, displacing all the air and suffocating some 1,700 people within 20 km of the lake, mostly rural villagers, as well as 3,500 livestock

Beats me, but I thought it somewhat related: point being, sometimes we just don't know much. supersaturated CO2 seems to only exist in lakes...

[GreyICE]

Originally Posted by mhaze

on August 21, 1986, a limnic eruption occurred at Lake Nyos which triggered the sudden release of about 1.6 million tonnes of CO2. The gas spilled over the northern lip of the lake into a valley running roughly east-west from Cha to Subum, and then rushed down two valleys branching off it to the north, displacing all the air and suffocating some 1,700 people within 20 km of the lake, mostly rural villagers, as well as 3,500 livestock

Beats me, but I thought it somewhat related: point being, sometimes we just don't know much. supersaturated CO2 seems to only exist in lakes...

Supersaturated CO2 exists nowhere for long. See definition: Supersaturated.

[Soapy Sam]

The Mammoth (Longrange)Caldera in California releases enough CO2 locally to be a hazard to people in the vicinity. That's when it's NOT erupting. During a major caldera eruption, CO2 is apt to be the least of any observer's concerns.

[mhaze]

Just curious - if it is presumed that we can pump CO2 down into the deep ocean to sequester it, why isn't the reverse equally plausible? That volcanic action deep in the ocean, could cause CO2, liquified at that depth, to boil to the surface?

[BenBurch]

Originally Posted by mhaze

Just curious - if it is presumed that we can pump CO2 down into the deep ocean to sequester it, why isn't the reverse equally plausible? That volcanic action deep in the ocean, could cause CO2, liquified at that depth, to boil to the surface?

Of course it could, if it were there, but we know how much CO2 is in the deep oceans already because that has been studied. And its not much. The water column does turn over and there are large-scale deep currents. An ocean is not at all like a deep volcanic lake.

Plus we know to a good degree of certainty where all of the sub-ocean vulcanism of any size is because we can HEAR it. Not only seismographs, but the major navies of the world are keenly interested in sounds out in the water.

So, no, not implausible that some day there could be a major outgassing, and not implausible that some day ocean currents could change and allow a really stagnant place to form that would act more like a deep volcanic lake, but now there is nothing like that.

Makes sense?

-Ben

[mhaze]

It makes sense only if the continual outgassing from underseas volcanos resulted in CO2 dispersion essentially to the standard ocean percentage. I'm not at all sure that would happen if the CO2 was continually in the liquid phase, which it would be in this case - then you have the simple, disturbing fact that CO2 liquid weighs more than water and would pool on the bottom. Which is why the concept of pumping it down there to sequester it was developed, right?

Have there been measurements close to underseas volcanos that substantiate this one way or the other?

[BenBurch]

Originally Posted by mhaze

It makes sense only if the continual outgassing from underseas volcanos resulted in CO2 dispersion essentially to the standard ocean percentage. I'm not at all sure that would happen if the CO2 was continually in the liquid phase, which it would be in this case - then you have the simple, disturbing fact that CO2 liquid weighs more than water and would pool on the bottom. Which is why the concept of pumping it down there to sequester it was developed, right?

Have there been measurements close to underseas volcanos that substantiate this one way or the other?

Oh yeah, people have been right down to the calderas with both submersibles and robotic vehicles, and water has been brought up; tends to be sulfuric acid!

Sequestering CO2 in the deep ocean is one of the dumber ideas. Safer by a lot to put it into an organic form and bury it. I've looked at using algae ponds for that, and you can make a case for it. Grow the algae on sewage water, and then when there is a nice mat in the big linear tray, let it dry and roll the mat up into bit circular bales like hay bales and then landfill it or put it into old mines...

And you can use it for fuel in steam producing plants too; died algae burns nicely though you pretty much have to design for that fuel as it is quite low density or use it mixed with other higher density fuels to extend them in a more carbon neutral fashion.

[Abdul Alhazred]

Originally Posted by BenBurch

Nice straw man too, if he only had a brain!

The first evidence against my initial rogue thought was posted here by ... me.

But I really shouldn't begrudge you your bon mot. I'm sure you were saving it up for a long time.

Mighty clever.