Methane seeps from Arctic sea-bed

reply to post by Long Lance


I would hazard a guess and say that the hydrates in the worlds oceans are the product of hundreds of millions of years of biology, to be honest. The sheer amount of biomatter that falls down to the ocean floor is mind-boggling. Whole ecosystems flourish on feeding on this matter, it stands to reason that methane would be a by product. This is then locked in place due to the temperature and pressure, but is released in great volumes when those temperatures change. This is known science and has been for quite some time.

There are two distinct types of oceanic deposit. The most common is dominated (> 99%) by methane contained in a structure I clathrate and generally found at depth in the sediment. Here, the methane is isotopically light (δ13C < -60‰) which indicates that it is derived from the microbial reduction of CO2. The clathrates in these deep deposits are thought to have formed in-situ from the microbially-produced methane, as the δ13C values of clathrate and surrounding dissolved methane are similar.[6]

These deposits are located within a mid-depth zone around 300-500 m thick in the sediments (the Gas Hydrate Stability Zone, or GHSZ) where they coexist with methane dissolved in the pore-waters. Above this zone methane is only present in its dissolved form at concentrations that decrease towards the sediment surface. Below it, methane is gaseous. At Blake Ridge on the Atlantic continental rise, the GHSZ started at 190 m depth and continued to 450 m, where it reached equilibrium with the gaseous phase. Measurements indicated that methane occupied 0-9% by volume in the GHSZ, and ~12% in the gaseous zone.[7]

In the less common second type found near the sediment surface some samples have a higher proportion of longer-chain hydrocarbons (

Ocean farts.....

.....awesome.

reply to post by pai mei


I will have to research it more. I find it hard to believe that temps at the bottom of the ocean floor have changed much, if at all, when the overall change in ocean temp has been relatively so small. It would have to be a substantial increase in water temp to change the water temp at that depth.

I am sure methane is constantly leaking from the ocean floor in spots. If it were a widespread phenomena it would be easy to detect.

Personally, I would worry more about the permafrost in the Arctic tundra melting first and releasing it's methane. That would probably happen before ocean temps reach the point of massive methane release.

Originally posted by punkinworks
There are billions and billions of tons of methane locked up in the frozen muds of arctic permafrost. These desposits have nothing to due with vulcanism.

There are large deposits of methane on the seafloor in a form as people have mentioned of methane hydrates.

These deposits will have a major effect of global temperatures if they are released.


Methane is released in volcanoes but in small amounts, volcanic gasses are mostly watervapor and hydrogen and sulfur compounds.

Methane is produced by life, primarily by it's decay by bacteria. It's kind of a constant as long as we have life on this planet. One would have to look at massive releases of methane into the atmosphere to see what had happened in the past. We are still coming out of the end of an Ice Age. Life tends to flourish more in the warmer periods of the Earth past than during the Ice Ages.

Originally posted by pavil
I will have to research it more. I find it hard to believe that temps at the bottom of the ocean floor have changed much, if at all, when the overall change in ocean temp has been relatively so small. It would have to be a substantial increase in water temp to change the water temp at that depth.

During some previous extinction events linked to massive methan release, the global temp only increased by a few degrees, this was enough to cause the release of enough methane gas with a greenhouse effect equivalent to ALL the worlds fossil fuels being burned at once.

Originally posted by pavil
I am sure methane is constantly leaking from the ocean floor in spots. If it were a widespread phenomena it would be easy to detect.

It does, yes, but in small amounts. This latest research shows it to be 100 times above the normal level, both here and in the Siberian Arctic..

Originally posted by pavil
Personally, I would worry more about the permafrost in the Arctic tundra melting first and releasing it's methane. That would probably happen before ocean temps reach the point of massive methane release.

Indeed, that is a worry, but there is far more methane trapped beneath the waves than in all the permafrost in the world combined. It only takes a couple of degrees warming to trigger the release of some of this gas, this then causes further warming, triggering the release of even more. By the time the permafrost metls and releases their gases, we'd be buggered anyway.

Hi there I flagged it for ya.

A book I read called The Swarm
From 2005 is written with scientific findings as back up.

Methane hydrate is mentioned.

It does not have anything to do with volcanoes.
I recommend the book By the Way !

Update from National Science Foundation.

Methane Releases From Arctic Shelf May Be Much Larger and Faster Than Anticipated

A section of the Arctic Ocean seafloor that holds vast stores of frozen methane is showing signs of instability and widespread venting of the powerful greenhouse gas, according to the findings of an international research team led by University of Alaska Fairbanks scientists Natalia Shakhova and Igor Semiletov.

reply to post by Jazzyguy


That whole article doesn't give any indication that there has been any increase in seafloor temps, which would be some data to work with. It sounds like they detected more methane release but don't know the cause for the increase.

Show me a study that documents the increase in sea floor temps in the Arctic Ocean, then you could have valid point. You would also have to show that the temp increase is coming from the sea surface rather than the increase coming from the seafloor, which would indicate other warming possibilities.

reply to post by Jazzyguy


Looks like Europe's gonna have to invest in ear muffs:

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Originally posted by K-Raz
reply to post by Nineteen

 

Volcanic activity off the sea of norway? Didn't know scandinavia was tectonichally active? There are methane deposits all over the planet, and it truly can set of a runaway effect - Same with the sibirian tundra and bogs.

I wish we could end the debate as to wether or not it's man made, and start focusing on what to do about it. The weather wont be getting more pleasant anywhere on the globe.

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yes as of matter of fact there is . heres a link .