Artic floor Methane Clathrates at -1.5C?

The permafrost has grown porous, says Shakhova, and already the shelf sea has become "a source of methane passing into the atmosphere." The Russian scientists have estimated what might happen when this Siberian permafrost-seal thaws completely and all the stored gas escapes.

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"A Wake-Up Call for Science"

Data from offshore drilling in the region, studied by experts at the Alfred Wegener Institute for Polar and Marine Research (AWI), also suggest that the situation has grown critical. AWI's results show that permafrost in the flat shelf is perilously close to thawing. Three to 12 kilometers from the coast, the temperature of sea sediment was -1 to -1.5 degrees Celsius, just below freezing. Permafrost on land, though, was as cold as -12.4 degrees Celsius. "That's a drastic difference and the best proof of a critical thermal status of the submarine permafrost," said Shakhova.

Paul Overduin, a geophysicist at AWI, agreed. "She's right," he said. "Changes are far more likely to occur on the sea shelf than on land."

Climate change could give an additional push to these trends. "If the Arctic Sea ice continues to recede and the shelf becomes ice-free for extended periods, then the water in these flat areas will get much warmer," said Overduin. That could lead to a situation in which the temperature of the sea sediment rises above freezing, which would thaw the permafrost.

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In any case, the team taking part in the Siberian study installed a number of probes in the Laptev Sea, a central part of the broad Siberian shelf sea. These probes are measuring the temperature on the upper edge of the submarine permafrost. Overduin wants to pull up the probes in August. Then, for the first time, scientists will have access to a full year's worth of data on the conditions of the sea floor.

For her part, Shakhova thinks researchers should be doing a lot more. She says too little is known about the fragile shelf sediment and the methane it stores, which could be explosive for the environment. "Actually," she says, "this is a wake-up call for science."

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Methane Discharges In The Arctic Pose Threat To Earth's Climate


VLADIVOSTOK, Aug 20 (Bernama) -- Methane discharges in the permafrost break-up process in the Arctic pose a threat to the entire terrestrial climate, Russian news agency, Itar-Tass, reported.

This hypothesis, put forward by scientists at the Pacific Oceanology Institute (POI) of the Far Eastern Branch of the Russian Academy of Sciences is being corroborated by this year's research, Igor Semiletov, participant in a research expedition, and staff member of the POI Arctic Research Laboratory, reported by telephone from board the hydrographic research vessel "Yakov Smernitsky" on Wednesday.

Specialists from the United States and Sweden had also participated in this research.

"Yet another POI expedition is currently at work in the Arctic, along with our's. The expedition members are exploring the Lena River mouth, where we discovered abnormally high concentrations of methane last year.

"POI researchers have already carried out 47 studies and confirmed as follows: the concentration of methane in water and the atmosphere increases at a rapid pace, which is indicative of the break-up of permafrost on the shelf of Arctic seas," Semiletov said.

This confirms the Russian scientists' hypothesis that greenhouse gas emissions in the Arctic can cardinally influence the Earth's climate, Semiletov pointed out.

"The obtained results will be validated once again when the Yakov Smernitsky will conduct additional research in the Lena River mouth in several weeks' time. However, already now one can say with confidence that the Arctic is one of the main 'suppliers' of greenhouse gases," Semiletov said.

The expedition aboard the vessel Yakov Smernitsky set out from Kirkiness port three days ago. The main task of the scientists on board is to reveal the boundaries of the underwater part of permafrost on the Arctic shelf and carry on the study of methane discharges into the atmosphere.
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Last year, a large international expedition that included oceanologists from Russia, Canada, the US, Britain, and Germany hd explored the entire Arctic coast and detected high concentrations of methane that exceeded the norm 1,000-fold. Researchers' opinion is that this may be connected with the disintegration of gas hydrates at the sea bottom, owing to a rise in the temperature of water and the atmosphere.

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To answer one of these questions (seasonal variability in methane release) an expedition led by Igor Semiletov was conducted over the Laptev Sea shelf. A tractor–sledge caravan started from Tiksi, Russia on March 30th (Fig.1). April 1st-April 15th was spent in the south-eastern part of the Laptev Sea eastward of the Lena River delta where 53 complex oceanogra*phic stations (CTD/water/sediment sampling) were done through 2m fast ice along the ~1,700km route. Methane measurements, gas extraction, pH and filtering samples were also processed in a mobile laboratory. Extremely high concentrations of methane (up to 10 μM – two orders of magnitude higher compared to summer concentrations) were measured in the water sampled from beneath the sea ice over the Ust’-Lena rift at the 72-73˚N latitude belt. Researchers suppose that seabed permafrost might be completely thawed in this area due to upward geothermal heat flux and heating effect of the Lena River runoff. This potentially allows methane from all three reservoirs to move upwards, reach the sea surface, and accumulate beneath the sea ice. Accumulation of methane occurs in the form of bubbles which can reach up to 1 m in diameter (Fig.2). All this methane trapped within bubbles and accumulated beneath the sea ice will release into the atmosphere when the ice melts in summer. Marine methane studies will be continued at IARC in our effort to understand atmospheric dynamics and natural forces that are contributing to our changing climate.

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Swedish researchers working on an international mission have confirmed that methane, a potent greenhouse gas, has started to leak from the permafrost under the Siberian seabed, Dagens Nyheter reported on Saturday.


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"The permafrost now has small holes. We have found elevated levels of methane above the water surface and even more in the water just below. It is obvious that the source is the seabed," Örjan Gustafsson, the Swedish leader of the International Siberian Shelf Study, told the newspaper.

The tests were carried out in the Laptev and east Siberian seas and used much more precise measuring equipment than previous studies, he said.

Methane is more than 20 times more efficient than carbon dioxide in trapping solar heat.

Scientists fear that global warming may cause Siberia's permafrost to thaw and thereby release vast amounts of methane into the atmosphere. The effects of global warming are already most visible in the Arctic region.

The Russia-Swedish expedition appeared to confirm a longer term trend based on readings by Russian researcher Igor Semiletov who first detected higher methane readings at several locations in the region in 2003.

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British scientists have discovered hundreds more methane "plumes" bubbling up from the Arctic seabed, in an area to the west of the Norwegian island of Svalbard. It is the second time in a week that scientists have reported methane emissions from the Arctic.

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they had counted about 250 methane plumes bubbling from the seabed in an area of about 30 square miles in water less than 400 metres (1,300 feet) deep off the west coast of Svalbard. They have also discovered a set of deeper plumes at depths of about 1,200 metres at a second site near by. Analysis of sediments and seawater has confirmed the rising gas is methane, said Professor Graham Westbrook of Birmingham University, the study's principal investigator.

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It is likely that methane emissions off Svalbard have been continuous for about 15,000 years

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GUSTAFSSON: Methane in the water on the East Siberian Artic Shelf is coming from sub-sea permafrost. This sea bottom used to be on land in the last ice age, and then was basically peat, that was frozen, permafrosted. And then the deglaciation—when it got warmer, the climate, then the sea levels was rising and the frozen peat was flooded. And it holds a large amount of methane. The conventional thought has been that this has been capped by the permafrost and held in place, but high levels of methane is now found in the seawater.

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GUSTAFSSON: There are three different mechanisms whereby this permafrost could be thawing. First one is geothermal heat flux. Basically, cracks in the Earth's crust where heat from Earth's interior is pushing up and thawing the permafrost. Another mechanism is basically when the sea level's rising and sea water's flooding over this land, then the sea water itself which might hold plus two degrees Celsius or so at sea bottom is providing heat to slowly thaw the permafrost. And final key mechanism is likely because of plumes of the very large Russian artic rivers that is pushing out warmer river water on the shelf—is also providing heat to thaw the permafrost.

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Well, I think we need to reconsider the notion that the permafrost is holding this huge methane reservoir in place, in the sea bottom. That's clearly not the case. There is methane being released now. And given the fact that methane is a much stronger greenhouse gas than carbon dioxide, I think what we need to do is to intensify these studies.

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For the last decade, however, methane emissions had somehow stabilized and even decreased slightly, while carbon dioxide levels increased rapidly. Scientists finally figured out that this was due to the fact that many wetlands were being drained for agricultural use, the increased capture of methane from landfills, and reduced emissions from the production of natural gas. But methane emissions have started to rise again due to increased consumption of fossil fuels in Asia. And an even bigger time bomb is ticking

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Permafrost soil in Siberia has started to melt for the first time since it formed 11,000 years ago at the end of the last ice age. It now threatens to release billions of tons of methane. According to Larry Smith, a hydrologist at the University of California, the west Siberian peat bog alone could hold some 70 billion tons of methane, a quarter of all of the methane stored in the ground around the world.

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The bad news first: Methane’s warming effect over a period of 100 years is 25 times stronger than that of CO2. Fortunately, methane appears in lower concentrations and disappears faster from the atmosphere than CO2. After about seven years, half of all methane emissions have transformed into water and carbon dioxide, a greenhouse gas in its own right.

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Methane concentrations in the atmosphere soared to the highest annual increase measured since 1998, Braathen said. The gas was at 1,789 parts per billion last year — a 0.34 percent increase from 2006.

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Scientists are quick to point out that the Arctic methane plumes could be anomalous or simply part of a longer-term trend. Natalia Shakhova, a biogeochemist at the University of Alaska, Fairbanks, and one of the leaders of the Siberian Shelf study, says, "Two years is nothing in geologic time scales." James Kennett, an Earth scientist at the University of California, Santa Barbara, agrees and says it is very possible that the Arctic methane releases "just simply weren't observed before."

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Both here and on land, permafrost stores vast quantities of carbon that could be converted to methane. Rich in organic material from dead plant and animal matter, thawed-out permafrost becomes alive with methane-producing microbes, which release the gas to the atmosphere. Some have compared it to unplugging a giant freezer: Warming temperatures could free up ancient carbon that's been safely tucked away for many thousands of years. "We've been putting carbon in this bank for 10,000 years," says White. "It's so cold that it doesn't decay away. But as the climate warms up, you start to take it out of the bank."

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The Siberian Shelf alone harbours an estimated 1,400 billion tonnes of methane in gas hydrates, about twice as much carbon as is contained in all the trees, grasses and flowers on the planet.

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Subsea permafrost is like a rock," explains Semiletov. "It works like a lid to prevent escape of any gas. We believe that the subsea permafrost is failing to seal the ancient carbon pool."

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Permafrost in the Northern Hemisphere is thought to contain some 950 billion tonnes of carbon; a little less than half of that is stored in highly organic-rich permafrost known as yedoma, much of which has been frozen since the Pleistocene, 10,000 years ago. Yedoma occupies about one million square kilometres of land, mostly in Siberia, where Katey Walter, an ecologist from the University of Alaska, Fairbanks, navigates rivers and lakes, frozen soil and even protruding mammoth bones to study methane emanating from the thawing ground. "We find that we get a lot more methane seeps where there's permafrost thawing," says Walter.

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A sign that this acceleration may have already begun comes from scientists who closely monitor concentrations of the gas in the atmosphere. Having remained stable for a decade, atmospheric levels of methane suddenly spiked in 2007

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They discovered permafrost several metres below the surface in northwestern Canada that dated back more than 700,000 years, suggesting that it has survived climates warmer than today's7. Froese says that while their findings suggest deep permafrost is stable, the research has no bearing on shallower sites.

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Levels of methane in the atmosphere rose 0.6 percent in 2008, according to preliminary data from the Zeppelin station on a remote island in the Norwegian Arctic, after a similar 0.6 percent gain in 2007, Norwegian officials said.

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“It’s difficult to say where the methane is coming from,” ...
“It could be methane from thawing permafrost ... We do not know,” she said.

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Other possible reasons for high recordings in the Arctic could include a shift in local winds. And new Arctic industrial sources include Russian coal and natural gas activities, or flaring from a StatoilHydro gas field.

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“North of the Brooks Range, the tundra is not yet melting, but south of the range, partial melting is already occurring. The south will give us clues to what’s likely to happen north of the range in the coming years,” said Colm Sweeney, of NOAA’s Earth System Research Laboratory (ESRL). Sweeney is head of a NOAA aircraft project that samples greenhouse gases around the country. NOAA ESRL monitors the gases from 60 sites worldwide.

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Earlier research documented large “bubbles” of methane near Arctic lakes. Satellite sensors revealed similar lakes in other areas, but whether those lakes produce methane is unknown. Last year research vessels in the Arctic Ocean observed methane vents releasing the gas from the ocean floor. Perhaps these vents have been there all along, undiscovered, say the scientists, or they could have developed recently.

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Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed.

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"Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be]," he said.

Professor Semiletov has been studying methane seepage in the region for the last few decades, and leads the International Siberian Shelf Study (ISSS), which has launched multiple expeditions to the Arctic Ocean.

The preliminary findings of ISSS 2009 are now being prepared for publication, he told BBC News.

Methane seepage recorded last summer was already the highest ever measured in the Arctic Ocean.

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