As if there weren't enough going on, Yale 360 reports
British and German scientists have discovered 250 plumes of methane gas rising from the thawing seabed off the Spitsbergen archipelago in the Norwegian Arctic, apparently a result of the warming of the West Spitsbergen current. The researchers measured the plumes rising from the seabed at a depth of 150 to 400 meters (500 to 1,300 feet). The methane — a potent greenhouse gas — is being released by frozen methane hydrates on the sea floor, which are thawing as a result of a 1 degree C (1.8 F) warming of the West Spitsbergen current in the last 30 years, the scientists said. Most of the methane is absorbed by the ocean before it reaches the surface, but the gas increases the acidity of the ocean, which inhibits the ability of marine creatures to grow shells. Scientists fear that as the world’s oceans warm, huge amounts of methane will be released. The Spitsbergen researchers said they were surprised by the large number of methane plumes. “Our survey was designed to work out how much methane might be released by future ocean warming,” said one scientist. “We did not expect to discover such strong evidence that this process has already started.”
Update: Lou Grinzo has a related entry, considering what "global warming potential" really means. I'm not sure the analysis is quite right, but the core point seems valid. A sufficeintly rapid release of methane might be worse than the GWP factor of 21 would indicate.
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Image from Treehugger.
15 comments:
My most recent Methane Checkpoint update (http://www.grinzo.com/energy/index.php/2009/07/17/methane-checkpoint-2/) was on July 17, and it shows that the global methane level is on quite a tear since late 2006.
This is extremely worrisome. It could be the first sign of something Very Bad happening, or it could be nothing more than just another uptick in methane (not that that would be good news), like the others shown in the graph in my post.
It's just a visual, but I was even more disconcerted by this image that ran with the story as reported by New Scientist: "Sonar image of methane plumes rising from the Arctic Ocean floor (Image: National Oceanography Centre, Southampton)"
When you think about trying to control anthropogenic point sources of ghg's, you can still at least conceive of it. But those pictures? Globally? Yikes is right... Hit the brakes. Hard.
Is there a reference so that we know this isn't the normal methane activity level?
Yup. Look back a couple of years at this story:
ScienceDaily (Feb. 7, 2007) — According to a recent paper published by MBARI geologists and their colleagues, methane gas bubbling through seafloor sediments has created hundreds of low hills on the floor of the Arctic Ocean. These enigmatic features, which can grow up to 40 meters (130 feet) tall and several hundred meters across, have puzzled scientists ever since they were first discovered in the 1940s.
Writing in the January issue of Geophysical Research Letters, MBARI geologists Charlie Paull and William Ussler and their coauthors described the results of field work they conducted on the Beaufort Sea Shelf, offshore of the north coast of Canada. In this area of year-round sea ice and permafrost, the team spent over a month mapping the seafloor and collecting sediment cores and gas samples from these underwater hills, which they call "pingo-like features."
"Pingos," small, dome-shaped, ice-cored hills, are found in many Arctic regions. "Pingo-like features" are similar in shape and size to pingos on land, but are found underwater, on the continental shelf in several parts of the Arctic. Previous studies have suggested that pingo-like features are pingos that formed on land but were submerged when sea level rose following the end of the last ice age, over 10,000 years ago.
Based on their geologic fieldwork and subsequent chemical analysis of the gas and sediments from eight pingo-like features, Paull and his coauthors propose an alternative hypothesis: Pingo-like features form when methane hydrate (a frozen mixture of gas and seawater) decomposes beneath the seafloor, releasing gas that squeezes deep sediments up onto the seafloor like toothpaste from a tube.
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So these little bumps would mark the places methane bubbled out as sea level fell from the last high stand, as the water went to make the icecaps of the previous ice age.
And ordinarily, without our involvement, cooling would be progressing now.
Instead we're warming things up past previous limits.
PS -- the older definition -- thinking those hills are made by permafrost -- is still easier to find:
http://www.answers.com/topic/pingo
PS, think of the irony if the entire coal and petroleum industry could shut down and be replaced by a program to drape huge sheets of polyethylene across huge areas of seabed, capturing methane, burning some of it (hey, better CO2 than methane gets released, at worst), using the power for refrigeration and compression to liquefy at least the methane for fuel.
Completely replace coal and oil with methane.
Yes, it'd be a desperation measure, but if the stuff's actually always been balanced more or less right at an equilibrium, for depth and temperature, with, some bubbling off and dissolving all the time, making pingoes -- then with the very rapid rate of change of rate of change we're causing now, it's going to be coming out very, very fast. No, the amount we could capture and burn to CO2 would probably be trivial compared to the amount reaching the atmosphere if this happens.
But it'd still make more sense to use what we could capture -- heck, put big generators with snorkels right on the seabed, pull air in, chill it to remove the nitrogen, burn the methane in the oxygen (at least avoiding making more nitrogen oxides, push the CO2, er, um, somewhere ... it'd have to be piped a long way for geological disposal, to get away from unstable gas sources, but could be done, maybe.
Yeah, it sounds insane, but if the methane hydrates really are tipping, and we're going to have a century or millenium of methane boiling out of the ocean, what else is there to do?
Remember:
If you can't stop'em, PETM.
Oh, and:
http://www.atmos-chem-phys-discuss.net/9/6855/2009/acpd-9-6855-2009.pdf
... first year from IASI
hyperspectral infrared observations
Simultaneous observations from the Infrared Atmospheric Sounding Interferometer (IASI) and from the Advanced Microwave Sounding Unit (AMSU), launched together onboard the European MetOp platform in October 2006, are used to retrieve a mid-to-upper tropospheric content of methane (CH4) in clear-sky conditions, in the Tropics, over sea, for the first 16 months of operation of MetOp (July 2007–October 2008).... A key point of this approach is that no use is made of prior information in terms of methane seasonality, trend, or geographical patterns. The accuracy of the retrieval is estimated to be about 16ppbv (∼0.9%)
Isotopic analysis would show the dif between primary CH4 and sediment CH4?
(preptuot)
PVC is made from ethylene, which is made from oil. Next
Gardner, J.V. 2009. Plume 1400 meters high discovered at the seafloor off the northern California margin. Eos 90(Aug. 11): 275.
http://www.sciencenews.org/view/generic/id/46526/title/Bubblin%E2%80%99_plume
"... Gardner and his colleagues suggest that the plume is made up of a stream of methane bubbles coated with a veneer of methane-rich ice. That ice coating, a material called methane hydrate, is stable in deep water, where pressure is high and the water is cold. When the ice-cloaked bubbles ascend into warmer waters near the surface, the ice melts and the methane dissolves into the sea. In the coming months, further analyses of water samples taken from the plume may confirm the team’s conjecture.
Although seafloor sediments in shallow areas closer to the coast are known to harbor methane, which often bubbles free of the ocean bottom, no one has reported such plumes in waters this deep, the researchers report. The newly discovered plume appears to originate within a previously unknown, amphitheater-shaped basin on the ocean floor. This 3.6-kilometer-wide scar was probably caused by a massive undersea landslide, Gardner says."
Hmm, that has a seriously journo-garbled feel to it. Sounds like the latest EOS, should be around here someplace...
Hence the title for the site 'Desdemona Despair'. We must find ways to adapt and mitigate, PDQ. (word verification calls it 'hicide').
Best,
D
EOS
Got it: p. 275; for those who've paid the AGU their pittance, you can read it online. EOS says:
"It appears from the characteristics of the feature that it is a plume of methane gas bubbles coated with a methane hydrate."
and points here; there's a readme, a .mov showing the plume and the shape of the seabed, and some zipped files:
http://ccom.unh.edu/NOAA_oceanexploration/
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Pure speculation on my part, I'd guess they mean frothy methane hydrate expanding (after the submarine landslide removed overpressure) and rising up and breaking apart -- not individual neat bubbles of methane in individual spheres of crunchy hydrate shell, but rather frozen foamed ice.
I recall other places have observed chunks of methane hydrate breaking loose and floating to the surface intact.
This event appears to have been a fast slump of a slope -- leaving a typical half-bowl-on-a-hillside, with a debris fan below it, and the bubbles are coming from the area that used to be well below the old slope surface.
> polyethylene
> PVC
(well, that's vinyl chloride, but I take your point, ethylene's from petroleum.)
So, rayon; capturing bubbles doesn't require an impermeable material, just one that they'll bounce along to gather them up. A plume like that one pictured is imaginable as a capturable source.
Barely. Maybe.
Oh, why bother ...
I'm sure if there's really a tipping point for large amounts of methane bubbling out fast enough that much ends up reaching the atmosphere, we're not going to capture enough to burn to reduce its total warming impact. If it's n
> http://www.grinzo.com/energy/graphics_misc/methane_2009x07x17.gif
Hmmm. Useful (for values of 'useful' that may, if there proves to be a trend, overlap both 'terrifying' and 'incapacitating')
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