Sentences with phrase «where methane hydrate»

Of course, it is precisely one of those exceptions that is most concerning to some of us, and Archer himself noted that, «The Siberian margin is one example of a place where methane hydrate is melting today, presumably at an accelerated rate in response to anthropogenic warming.

The zone where methane hydrate remained stable now shrank.

In some parts of the Arctic Ocean, the shallow regions near continents may be one of the settings where methane hydrates are breaking down now due to warming processes over the past 15,000 years.

As countries produce more conventional and unconventional fuels, the planet is warming in areas where methane hydrates exist.

And note their Section 4 — contemplating what happens if deep warm water currents change in a way that changes the current temperature in areas where methane hydrates are in equilibrium, suggesting the possibility of a rapid large scale release of methane gas.

Not exact matches

At a lower pressure — approximately 4 GPa — methane and molecular hydrogen interact, forming co-crystals (where two molecules together create one crystal structure), and at 6 GPa, hydrates — CO-crystals made of methane and water — are formed.

Natural methane hydrates were first discovered by Russian scientists in the late 1960s in Siberian permafrost — where the ground is so cold that hydrates can form at shallower depths and at lower pressures than under the sea — and then, in the 1970s, at the bottom of the Black Sea.

But no matter where researchers now drill under the sea, they find methane, often in the form of a hydrate.

Exponentially less methane would be able to reach the atmosphere in waters that are thousands of feet deep at the very edge of the shallow seas near continents, which is the area of the ocean where the bulk of methane hydrates are,» Sparrow says.

Even where methane increases are observed at the ocean surface, scientists need better data to determine whether emissions come from hydrates or other seafloor sources.

Beyond that, more than 95 percent of the world's methane hydrates exist in deep - ocean settings where it is unlikely water would ever heat up enough to significantly destabilize them.

Worldwide, particularly in deeply buried permafrost and in high - latitude ocean sediments where pressures are high and temperatures are below freezing, icy deposits called hydrates hold immense amounts of methane (SN: 6/25/05, p. 410).

The only place where melting methane hydrates appear to be releasing methane to the atmosphere is on the Siberian margin, where hydrates associated with the permafrost relict from the last glaciation release methane to the shallow water column of the shelf waters.

I'd love to know what they did take into account in attempting to model that period — must include astronomical location, sun's behavior, best estimates about a lot of different conditions — where the continents were, what the ocean circulation was doing, whether there had been a recent geological period that laid down a lot of methane hydrates available to be tipped by Pliocene warming into bubbling out rapidly.

The most likely explanation is the mass release of methane from sediments on the sea floor, where the gas was sequestered, as it is now, in a solid form as methane hydrate.

The only place where melting methane hydrates appear to be releasing methane to the atmosphere is on the Siberian margin, where hydrates associated with the permafrost relict from the last glaciation release methane to the shallow water column of the shelf waters.

I just go to the section where they get into discussing Arctic seabed methane in more detail, and the conclusion of that section is actually: «In summary, the ocean methane hydrate pool has strong potential to amplify the human CO2 release from fossil fuel combustion over time scales of decades to centuries.»

The exceptions are hydrate in permafrost soils, especially those coastal areas, and in shallow ocean sediments where methane gas is focused by subsurface migration.»

Plumes of rising methane bubbles have been mapped off the coast of Svalbard to where the water is about 400 meters deep — the edge of the stability zone for hydrates.

Elsewhere in the same paper, Archer describes how this could come from the methane trapped in the ice being smoothed through «diffusion within the fern or heterogeneous bubble closure depth,» or simply through the methane sampling not being dense enough, where the maxima of release could be overlooked [Archer, Methane hydrate stability and anthropogenic climate change, Biogeosciences,methane trapped in the ice being smoothed through «diffusion within the fern or heterogeneous bubble closure depth,» or simply through the methane sampling not being dense enough, where the maxima of release could be overlooked [Archer, Methane hydrate stability and anthropogenic climate change, Biogeosciences,methane sampling not being dense enough, where the maxima of release could be overlooked [Archer, Methane hydrate stability and anthropogenic climate change, Biogeosciences,Methane hydrate stability and anthropogenic climate change, Biogeosciences, 2007].

Methane hydrate in ocean seabed sediments is a potential source of methane (CH4) to the atmosphere, where CH4 has potential to act as a powerful greenhouMethane hydrate in ocean seabed sediments is a potential source of methane (CH4) to the atmosphere, where CH4 has potential to act as a powerful greenhoumethane (CH4) to the atmosphere, where CH4 has potential to act as a powerful greenhouse gas.

Methane Hydrates» Melt - was first observed to be accelerating during the last decade, with sufficient ocean warming reaching the hydrates in the sea bed of continental shelves off Norway and eastern Canada, where the hydrate stocks are vulnerable to newly warmed cHydrates» Melt - was first observed to be accelerating during the last decade, with sufficient ocean warming reaching the hydrates in the sea bed of continental shelves off Norway and eastern Canada, where the hydrate stocks are vulnerable to newly warmed chydrates in the sea bed of continental shelves off Norway and eastern Canada, where the hydrate stocks are vulnerable to newly warmed currents.

James Hansen, adjunct professor, Department of Earth and Environmental Sciences, Columbia University and former Head of the NASA Goddard Institute for Space Studies claims the melting ice could lead to the point where ocean floor warming triggers massive release of methane hydrate, i.e., methane molecules trapped in ice crystals, which would become a «tipping point.»

Vast quantities of methane hydrates are also found throughout the world just below the seabed, in locations where water depths are greater than a few hundred metres.

«The most likely process where this happens - and there is geological evidence that it has happened in the past - is when the methane gas hydrate layer in the sediment destabilises on a slope.

Can you point out to me where the record demonstrates anything near the kind of rapidity of changes being claimed anecdotally for methane hydrate dissolution?

Even on the Siberian continental margin, where water temperatures are colder than the global average, and where the sediment column retains the cold imprint from its exposure to the atmosphere during the last glacial time 20,000 years ago, any methane hydrate must be buried under at least 200 m of water or sediment.

It would be quite a coincidence, Berndt said, to find methane emissions in a place where the water is warming and where there are known hydrate deposits — and to have those three things be completely unrelated.

Warming bottom waters in deeper parts of the ocean, where surface sediment is much colder than freezing and the hydrate stability zone is relatively thick, would not thaw hydrates near the sediment surface, but downward heat diffusion into the sediment column would thin the stability zone from below, causing basal hydrates to decompose, releasing gaseous methane.

R&D ers have been talking up natural gas extraction from methane hydrates — a solid form of the greenhouse gas, found tucked away beneath the sea floor where low temperature and high pressure keep it stable.

The work being done by the USGS is intended to not only discover where large concentrations of methane gas hydrates are located, but also to determine the best method for safely extracting the methane trapped in the hydrate.

RE methane hydrates, here's a NYT article that claims we don't have to worry about the deeper ones for 1000s of years because the ocean is slow in warming, esp down at the bottom where the hydrates are (tho some scientist aren't sure about that): http://green.blogs.nytimes.com/2011/12/20/arctic-methane-is-catastrophe-imminent/?partner=rss&emc=rss

RealClimate is wonderful, and an excellent source of reliable information.As I've said before, methane is an extremely dangerous component to global warming.Comment # 20 is correct.There is a sharp melting point to frozen methane.A huge increase in the release of methane could happen within the next 50 years.At what point in the Earth's temperature rise and the rise of co2 would a huge methane melt occur?No one has answered that definitive issue.If I ask you all at what point would huge amounts of extra methane start melting, i.e at what temperature rise of the ocean near the Artic methane ice deposits would the methane melt, or at what point in the rise of co2 concentrations in the atmosphere would the methane melt, I believe that no one could currently tell me the actual answer as to where the sharp melting point exists.Of course, once that tipping point has been reached, and billions of tons of methane outgass from what had been locked stores of methane, locked away for an eternity, it is exactly the same as the burning of stored fossil fuels which have been stored for an eternity as well.And even though methane does not have as long a life as co2, while it is around in the air it can cause other tipping points, i.e. permafrost melting, to arrive much sooner.I will reiterate what I've said before on this and other sites.Methane is a hugely underreported, underestimated risk.How about RealClimate attempts to model exactly what would happen to other tipping points, such as the melting permafrost, if indeed a huge increase in the melting of the methal hydrate ice WERE to occur within the next 50 years.My amateur guess is that the huge, albeit temporary, increase in methane over even three or four decades might push other relevent tipping points to arrive much, much, sooner than they normally would, thereby vastly incresing negative feedback mechanisms.We KNOW that quick, huge, changes occured in the Earth's climate in the past.See other relevent posts in the past from Realclimate.Climate often does not change slowly, but undergoes huge, quick, changes periodically, due to negative feedbacks accumulating, and tipping the climate to a quick change.Why should the danger from huge potential methane releases be vievwed with any less trepidation?

The commentary speculates methane hydrates, ice - like substances where the gas is stored in the East Siberian Arctic shelf (among other places), could unleash a 50 gigatonne «pulse» of methane between 2015 - 2025 (leading to an atmospheric concentration six times current levels) as undersea permafrost thaws.

Down where the hydrates are, there is neither sulfate nor oxygen, so there's no way for bacteria to make a living feeding on the methane.