Source: Oceanfloor Craters Hint Of Potential Arctic Methane Explosions In The Future : SCIENCE : Tech Times The study led by Professor Karin Andreassen of CAGE revealed at least a hundred kilometer-wide (0.6 miles) craters and several hundred smaller ones littering the Arctic sea floor. All the craters were once methane domes that exploded about 12,000 years ago, but research reveals that at least 600 areas within and outside the craters continue to release methane gas, which poses potential danger in the years to come. The study is behind a paywall that requires 'free' registration. I'm thinking about it. Bob Wilson
Ice-core bubbles show methane increased (not quite doubled) between 15 thousand and 10 thousand years ago. This would be about the right timing but I don't think that its 13/12 carbon isotope ratio can lead to an unambiguous source.
I'm assuming the "13/12 carbon isotope ratio" is an indication of formation age of hydrate metric? Would 14-C play no role? Bob Wilson
Not age - stable isotopes do not inform. More related to origin in different biological pools. Terrestrial and marine organic matter does not differ here, I understand, so it is not clear where all that new methane came from. But that concentration increase does not contradict sea-floor methane evulsion. It may be that 14C remains poorly understood. For most bio-material, C14 shows its concentration when it was last 'connected' to the atmosphere. Latter having (nearly) constant levels of 14C. After disconnect, half is lost per 5730 (or 5760) years. Half of remaining half after than time again. Etc. So 14C only informs on (that sort of) age and not at all about what the carbon source might have been. In most recent few decades, 14C 'counting' has become much more precise. But I don't suppose that ice bubbles are optimal place to spend your money.
Most amazing thing about 14C recently is that atmosphere got a large additional boost centered on 1962 . A few experiments that could make use of that spike have been done. Most are still in thought-space. So much of carbon cycling happens on this very human timescale. Blahblahblah.
Ok, that makes sense ... maybe. Is there a question of whether it came from fossil sources? I had not considered it but given the oil reserves under the Gulf of Mexico, a fossil source would be feasible. In error, I had assumed methane hydrates formed from organic means on the bottom of the ocean. Sounds like a research proposal. Bob Wilson
No doubt there are biological pools that differ in 13/12C. And they emit CO2 with their signature. But then you have atmospheric blender, followed by localized entrainment in ice-core bubbles. Information loss at the blender step.
Marine sediments with organic material (and short on O2) source methane because bacteria there have no better energy source. Where water above is cold and high-enough-pressure, methane clathrate forms and hangs around until 'the door upstairs opens'.
Entropy always wins@9. Well, yes, eventually. I guess. Biology is 'one weird trick' by which entropy can be held at bay, if some energy gradient can be pirated. Gravity is another, by which matter accumulates in negentropic ways. From scales of loosely clumped comets to planets to star-bound systems to galaxies and higher. Maybe entropy is over-rated. An entropy-dominated universe would just be an isotropic smear of atoms, containing no critters capable of wondering. Not quite like that in these parts.
At their scales, atoms are profoundly low on entropy. 'Strong force' allows protons to snuggle up. Neutrons hate their lives except where similarly snuggled. Around such clumps, electrons find energetic happy homes, quite against entropy's call. In molecules, electrons just have larger, happier homes. Across more than 30 orders of magnitude, we might better say that entropy wins only where all other 'forces of nature' have left strategic openings. Or more than 40? I'd have to make another frikkin' spreadsheet...
