Skip to comments.Deep-sea volcanoes don't just produce lava flows, they also explode!
Posted on 03/28/2011 2:04:55 PM PDT by decimon
McGill geology researchers' discovery of high concentrations of CO2 at mid-ocean ridges confirms explosive nature of certain volcanic eruptions
Between 75 and 80 per cent of all volcanic activity on Earth takes place at deep-sea, mid-ocean ridges. Most of these volcanoes produce effusive lava flows rather than explosive eruptions, both because the levels of magmatic gas (which fuel the explosions and are made up of a variety of components, including, most importantly CO2) tend to be low, and because the volcanoes are under a lot of pressure from the surrounding water.
Over about the last 10 years however, geologists have nevertheless speculated, based on the presence of volcanic ash in certain sites, that explosive eruptions can also occur in deep-sea volcanoes.
But no one has been able to prove it until now.
By using an ion microprobe, Christoph Helo, a PhD student in McGill's Department of Earth and Planetary Sciences, has now discovered very high concentrations of CO2 in droplets of magma trapped within crystals recovered from volcanic ash deposits on Axial Volcano on the Juan de Fuca Ridge, off the coast of Oregon.
These entrapped droplets represent the state of the magma prior to eruption. As a result, Helo and fellow researchers from McGill, the Monterey Bay Aquarium Research Institute, and the Woods Hole Oceanographic Institution, have been able to prove that explosive eruptions can indeed occur in deep-sea volcanoes. Their work also shows that the release of CO2 from the deeper mantle to the Earth's atmosphere, at least in certain parts of mid-ocean ridges, is much higher than had previously been imagined.
Given that mid-ocean ridges constitute the largest volcanic system on Earth, this discovery has important implications for the global carbon cycle which have yet to be explored.
For an abstract of the article: http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1104.html
The complete article is available on request.
Credit: NOAA/National Science Foundation
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Low blow ping.
This business about volcanoes releasing CO2—this is absolute nonsense. The concentration of CO2 in the atmosphere is entirely due to selfish Americans driving SUVs and pickup trucks we don’t really need. And to our absurd insistence upon using electricity, too!
The West MUST raise taxes to prevent any further global geologic change!
If sub sea volcanoes are releasing CO2, doesn’t that suggest vast deep hydrocarbon deposits?
I think all volcanoes release CO2.
[I think all volcanoes release CO2.]
Yes, I was just thinking out loud. I just wonder how much carbon is trapped in the mantle to be transformed?
Don't worry, the EPA will fix this. They can simply prohibit US citizens from exhaling for two months after each underwater eruption.
It’s been known for quite a while that the increasing amount of atmospheric CO2 is much greater than can be explained by anthropogenic CO2, especially since the increase started before the beginning of the Industrial Revolution.
Something not mentioned here is the oceans acting as a CO2 sink, taking CO2 from the air. If these volcanoes are releasing to the oceans some great amount of CO2 then that must, I would think, much alter their equations. I think that's suggested in this release and probably appears in the study.
And submarines can hit what they produce.
Hey, it takes great aim to find a mountain in the middle of the Pacific.
Or a last years chart.
The Juan de Fuca plate being off the Oregon coast, what danger does a major undersea eruption have for our northwest coast? Either earthquake or poison gas?
I would think that there would be some type of equilibrium over long periods of time. IIRC, the long term reduction of atmospheric CO2 over geologic time is due to the weathering of rocks.
I’m always afraid to use “Juan de Fuca” in a sentence.
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