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15 Nov 10 - "In a surprise finding, undersea hot lava is baking ocean sediments and releasing greenhouse gases," says this article by Larry O'Hanlon
Scientists had previously thought of the oceans as being a carbon sink, says O'Hanlon. This reverses that belief, changing the oceans into a carbon source.
"The discovery has big implications for calculating the Earth's current carbon budget, as well as for how past climates were thrown in to disarray by "intrusive" volcanic activity beneath the seafloor," says O'Hanlon.
Researchers at the Woods Hole Oceanographic Institution were especially surprised at how far the magma had spread. "The sills of magma were not just a few kilometers (1.8 miles) away from the spreading center ridge, as expected, but up to 50 kilometers (31 miles) away. That vastly increases the volume of sediments the hot rock can cook and from which methane and other carbon-rich gases can be released. "Sills derived from intrusive volcanism in sedimentary basins have been linked to huge natural methane fluxes in the past," says David Goldberg of the Lamont-Doherty Earth Observatory, who cites as an example the 55-million-year-old sills of the Norwegian margin, "suspected of having caused global climate change."
"All that gas buoys up through the sediments and into the ocean, heating up the deep waters." (Italics added)
http://news.discovery.com/earth/deep-sea-lava-climate.html See videos: Undersea Volcanic Eruptions Spotted in Action Underwater Volcano Eruption Caught on Camera
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