I’m having a holiday, from both work and my studies. But thanks for the offer – email on way.

If I continue I’ll look into your suggestion and contemporary biological activity. It’s interesting that this has increased notably for 2007/2008. I can’t figure out quite why – I had been pondering land warming/ocean warming or more fragmented ice. But right now I’m re-reading a load of Brian Aldiss.

Sonny

Were there not such interest in the Arctic and in the clathrates, what the ISSS08 team are now discovering would be the unobserved precursor to what would be found by those investigating the reason for the negative excursion in 13C that will come.

I can’t access the Nature paper by Dickens that you refer to. But thanks for the links above, Modern bacterial activity looks interesting. Also thanks for the japanese publication link, if I continue studying this issue I’ll be browsing there.

“Got a little feelin’ times is gonna be bad.
Those good ol’ days have all a been had.
If now is where tomorrow’s come to rehearse.
Today the future just got much worse.”
Robert Newman, “History of Oil”

I admit, I hadn’t made the mental link earlier because I tend to think of Arctic and volcanoes as unrelated…except of course for the paper that Stephen cited in post 5 above: ‘The Svensen one was a bit stats-y, but massive explosions are always interesting.’
So, you just had to mention a high 13C in Arctic methane, didn’t you?
Thanks, CobblyWorlds. I can sleep *so* much better now (finding a plausible scientific reason for a big bang is an occupational hazard for me, I’m afraid )

Sonny

This might supply a clue: http://www.iarc.uaf.edu/highlights/2006/arctic_ocean_methane/index.php

The key phrase being, “Upon thawing they (methane producing bacteria) restore activity and begin to produce a lot of modern methane from ancient organic matter preserved within the permafrost.

Sonny

I’d very much like to see 13C measurements from the subsea (if they took them), underwater, and atmospheric samples taken by the Yakov Smirnitsky team. Someone else must be measuring the 13C and 12C from clathrates outgas. I’ll see if I can track down some research. I’m quite intrigued.

Sonny

My post is here.

I got no answer there. Anyone here got any ideas?

For what it’s worth I think it rules out the current methane increase being due to clathrates. However that doesn’t mean at some stage that the isotope fraction change won’t go the other way (as clathrates outgas).

http://www.cosis.net/abstracts/EGU06/05277/EGU06-J-05277.pdf
“Anthropogenic methane emissions and recent trends in atmospheric methane concentrations.” E Matthews 2006.

Reduced emissions from the former Soviet gas/oil industry have been implicated in the lower growth rate in the early 1990s… …Most anthropogenic sources exhibit flat or slightly increasing/declining emissions since 1980 but the time series of fossil fuel (FF) source differs in magnitude and trend among researchers.

Hope that helps.