The Atlantic is leaking methane – but researchers say there's no cause for alarm

methane_bubbles[1]We’ve seen all this before, but there is a twist this time, the authors of the paper are dialing back the alarm a bit.

“…authigenic carbonates observed imply that emissions have continued for more than 1,000 years at some seeps.”

From the BBC – 24 August 2014 ‘Widespread methane leakage’ from ocean floor off US coast

Researchers say they have found more than 500 bubbling methane vents on the seafloor off the US east coast.

The unexpected discovery indicates there are large volumes of the gas contained in a type of sludgy ice called methane hydrate.

There are concerns that these new seeps could be making a hitherto unnoticed contribution to global warming.

The scientists say there could be about 30,000 of these hidden methane vents worldwide.

Previous surveys along the Atlantic seaboard have shown only three seep areas beyond the edge of the US continental shelf.

Here is the sonar image:

Atlantic_methane_plumes

………..

There are concerns that these new seeps could be making a hitherto unnoticed contribution to global warming……..

The scientists say that the warming of ocean temperatures might be causing these hydrates to send bubbles of gas drifting through the water column….

But it is important to say we simply don’t have any evidence in this paper to suggest that any carbon coming from these seeps is entering the atmosphere.”

http://www.bbc.com/news/science-environment-28898223

h/t to reader “Jimbo” in Tips and Notes

The paper:

Widespread methane leakage from the sea floor on the northern US Atlantic margin

Sharke et al. Nature Geoscience (2014) doi:10.1038/ngeo2232

Methane emissions from the sea floor affect methane inputs into the atmosphere1, ocean acidification and de-oxygenation2, 3, the distribution of chemosynthetic communities and energy resources. Global methane flux from seabed cold seeps has only been estimated for continental shelves4, at 8 to 65 Tg CH4 yr−1, yet other parts of marine continental margins are also emitting methane. The US Atlantic margin has not been considered an area of widespread seepage, with only three methane seeps recognized seaward of the shelf break. However, massive upper-slope seepage related to gas hydrate degradation has been predicted for the southern part of this margin5, even though this process has previously only been recognized in the Arctic2, 6, 7. Here we use multibeam water-column backscatter data that cover 94,000 km2 of sea floor to identify about 570 gas plumes at water depths between 50 and 1,700 m between Cape Hatteras and Georges Bank on the northern US Atlantic passive margin. About 440 seeps originate at water depths that bracket the updip limit for methane hydrate stability. Contemporary upper-slope seepage there may be triggered by ongoing warming of intermediate waters, but authigenic carbonates observed imply that emissions have continued for more than 1,000 years at some seeps. Extrapolating the upper-slope seep density on this margin to the global passive margin system, we suggest that tens of thousands of seeps could be discoverable.

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2232.html

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August 25, 2014 1:08 pm

What´s collision between Tectonical plates? What’s to be found in re. chemical elements under tectonical plates? Is it possible that “researchers” never ever learnt what an ordinary school’s 8th grader should know?

johnmarshall
Reply to  norah4you
August 27, 2014 4:09 am

There are two subduction zones in the Atlantic, one in the eastern Caribean the other in the Southern Oceanic part of the Atlantic. There are no subduction zones off the American east coast. The west coast yes.

Reply to  johnmarshall
August 27, 2014 7:32 am

Almost correct, but not exactly. There are some even if they are minor on American east coast far north.

August 25, 2014 1:08 pm

Global Warming is causing methane. Ocean temperatures are rising. Let’s not forget ocean acidification.
Hundreds of ‘toxic’ methane vents discovered in the Atlantic’s depths – and they could be caused by global warming
A large number of methane vents have been found off the US East Coast
Suggests such leakage is far more widespread in the Atlantic than thought
Previously only three seepage areas had been known of in this area
Increased levels of methane can make water more acidic and deadly to life
The vents could be caused by a warming ocean linked to climate change
http://www.dailymail.co.uk/sciencetech/article-2733719/Hundreds-methane-vents-Atlantic-Discovery-570-seepage-areas-stuns-scientists.html

johnmarshall
Reply to  Cam_S
August 27, 2014 4:12 am

Ocean pH levels have remained within their natural levels 7.6-8.4 ever since it has been measured. Even with the current SLIGHT rise of CO2. In no way can the oceans be called acid. They are all alkal.

Jimbo
August 25, 2014 1:12 pm

“But it is important to say we simply don’t have any evidence in this paper to suggest that any carbon coming from these seeps is entering the atmosphere.”

Could it be due to the Methane-Consuming Archaea?
http://www.sciencemag.org/content/293/5529/484.short

…….but authigenic carbonates observed imply that emissions have continued for more than 1,000 years at some seeps. Extrapolating the upper-slope seep density on this margin to the global passive margin system, we suggest that tens of thousands of seeps could be discoverable.

Could it be the seeps were always there? Just asking.

MattS
August 25, 2014 1:13 pm

If only we could capture that methane for energy? Hmmm.

Jimbo
August 25, 2014 1:20 pm

For any passers by who are wondering: methane seeps are nothing new. They have been around for such a long time that there are methane eating bacteria – as well as natural oil seep eating bacteria.

Eocene deep-sea communities in localized limestones formed by subduction-related methane seeps, southwestern Washington
http://geology.gsapubs.org/content/18/12/1182.short

wws
August 25, 2014 1:21 pm

Any mention from anyone that this has been going on forever, and will continue to go on forever? (or at least within the time of Man’s presence here)
They act like a thousand plumes just started up yesterday, because Climate Change or something.

richard
August 25, 2014 1:22 pm

is the Methane gas biogenic or thermogenic .

J
August 25, 2014 1:25 pm

Cam_S,
You didn’t read the article abstract did you?
Global warming is not “causing” the methane. The abstract clearly says that based on the deposits, some of these vents have been releasing methane for more than a 1000 years.
And, no ocean temperatures may be technically rising, but due to the vast heat capacity of water compared to the atmosphere, the temperature rise on average is hundredths and even thousandths of a degree ! Not enough to change methane processes.
Refresh my chemistry, how does a neutral hydrocarbon molecule like CH4 make water acidic?
The link you cite blames bacteria for generating the methane not humans.

Jimbo
August 25, 2014 1:28 pm

MattS
August 25, 2014 at 1:13 pm
If only we could capture that methane for energy? Hmmm.

The work on that energy source has already begun.

BBC – 12 March 2013
Japan extracts gas from methane hydrate in world first
http://www.bbc.com/news/business-21752441
==================
HuffPo – 04/16/2013
Arctic’s Methane Hydrate Supply May Be Tested For Energy Use In New Study
The DOE; ConocoPhillips; and Japan Oil, Gas and Metals National Corp. completed field work on a nearly $29 million experiment to extract methane hydrate. The research focused on an extraction technique developed by ConocoPhillips and the University of Bergen in Norway in which researchers injected carbon dioxide into methane hydrate. The carbon dioxide molecules swapped places with methane molecules, freeing the methane to be harvested but preserving ice in the reservoir.
http://www.huffingtonpost.com/2013/04/17/arctic-methane-hydrate-alaska-energy-study_n_3096426.html

Carbon capture does have its uses after all. 😉

Dr. Strangelove
Reply to  Jimbo
August 26, 2014 10:58 pm

If methane hydrate is economical, the Big Oil will be scrambling to put pipelines under the sea. The concentration is too low. It’s more economical to extract methane from toilets, sewage, cow and pig manure. There’s energy in shit.

copernicus34
August 25, 2014 1:28 pm

they are dialing down the alarmism because Man cannot be blamed for this, this would in some way detract with their goal.

AnonyMoose
August 25, 2014 1:30 pm

It’s nice that someone has some more number on this, but it’s hardly surprising. Many hydrocarbon deposits are known in eastern states, so it’s quite likely that similar formations extend under the coast. Also, the underwater terrain has ongoing erosion, although a different type of erosion than during the glacial eras when much coastal land (which is presently underwater) was exposed to rainfall erosion. The continental shelf certainly is not a sealed reservoir area, so of course there is leakage there.

Jimbo
August 25, 2014 1:32 pm

Cam_S,
all I see is COULD. I could sneeze in 5 minutes time.

cg
August 25, 2014 1:42 pm

Methane? By product of an animal farting. I kid you not.

kadaka (KD Knoebel)
August 25, 2014 1:47 pm

This is when the nutters show up, claim this is proof of abiotic oil, point to Thomas Gold’s The Deep Hot Biosphere: The Myth of Fossil Fuels, and further claim there is an endless supply of energy from methane available as the planet itself is constantly making it which completely ignores the replenishment versus the potential removal rates while not noting all the other critters and natural processes that consume the methane.
What more proof do you need these people are raving loonies than Amazon saying this book is Frequently Bought Together with The Great Oil Conspiracy: How the U.S. Government Hid the Nazi Discovery of Abiotic Oil from the American People by Jerome R. Corsi (2012)?

Latitude
August 25, 2014 1:48 pm

they discovered denitrification in the ocean……I’m shocked

August 25, 2014 1:53 pm

Richard – they report it is biogenic. So…. what’s the story here, right?
zzzzzz………

Bruce Cobb
August 25, 2014 2:01 pm

Some Gas-X should do the trick.

kenw
August 25, 2014 2:10 pm

saw something a while back that indicated large volume outbursts of a gas from the ocean floor could rise and foil the bouyancy of ships, causing them to sink rather instantly. It was being proposed as a Burmuda Triangle ’cause’. At the time the rising gas was indicated (to me) to be well known, the theory part at that point was the large volume aspect as if it could collect/’pool’ under sediment and then burst forth once the overburden was lifted. Like a large belch. A large, flammable belch.

rogerknights
August 25, 2014 2:11 pm

Quick, the Beano!
If these methane leaks aren’t new, but were only recently discovered, or if they a new only because they are cyclic, then that means that released methane doesn’t make it up to the upper atmosphere, where its incidence hasn’t been rising much.

SIGINT EX
August 25, 2014 2:15 pm

🙂
Step 1) 2 NaCl (Salt) + 2 H2O -> 2 NaOH + H2 + Cl2 (Chlorine Gas)
Step 2) CH4 (Methane) + 4 Cl2 → CCl4 (Carbon Tetrachloride) + 4 HCl (Hydrochloric Acid)
In Step 2 Carbon Tetrachloride escapes the oceans to make the Ozone holes at the poles and becomes the nemesis of the Montreal Protocol and we get ocean acidification from Hydrochloric Acid.
Voilà!

August 25, 2014 2:29 pm

Jimbo is more right than he chooses to claim.
If methane vents change then all the microbes that live because of the natural release of that simple, natural compound will be affected. They will boom! Or they will decline!
Remember the BP muck-up in the Gulf of Mexico. Aquatic microbes fixed that.
Environmentally stabilising feedbacks are preferred by Darwinian selection.
As Douglas Adams wrote, “Don’t Panic”.

ShrNfr
August 25, 2014 2:32 pm

Seep and you shall find. So read it and seep.

EternalOptimist
August 25, 2014 2:36 pm

I read an interesting theory many decades ago, probably in ‘Omni’
where the bermuda triangle mysteries were explained by methane hydrates
I sort of remember reading at the same time, that a quarter of human CO2 was being produced by peat burning underground in Indonesia, set alight by forest clearance and subsequent drying of the peat.
I would have paid more attention if I had known about the lunacy that has been foisted upon us since

Martin Hodgkins
August 25, 2014 2:47 pm

I just looked back and realised it said “no cause for alarm”. It had me worried there for a minute you know methane and all that. Thank god for that.

August 25, 2014 2:59 pm

And bring a towel.

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