In September Steve Bloom gave us a pointer to this:
Commercial shipping through the Northeast Passage over the last couple weeks has reported the seas bubbling as if they were boiling. Their observations have been reported to the science ministry who have sent scientists to investigate.
The story hasn't gone away and hasn't gotten any more reassuring:
Igor Semiletov, of the Far Eastern branch of the Russian Academy of Sciences, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.
"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures, more than 1,000 metres in diameter. It's amazing," Dr Semiletov said. "I was most impressed by the sheer scale and high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them."For further context, see here.
See also here:
The East Siberian Arctic Shelf is a methane-rich area that encompasses more than 2 million square kilometers of seafloor in the Arctic Ocean. It is more than three times as large as the nearby Siberian wetlands, which have been considered the primary Northern Hemisphere source of atmospheric methane. Shakhova's research results show that the East Siberian Arctic Shelf is already a significant methane source, releasing 7 teragrams of methane yearly, which is as much as is emitted from the rest of the ocean.This is one of those things; one of those things that was not supposed to happen. Or not happen for a long time. Or happen very slowly. To have methane boiling out of the Arctic sea, unoxidized, in plumes a kilometer across, in volumes sufficient to raise the local atmospheric levels of methane by a factor of a hundred . . . these are hard and heavy tidings. Hard to know what they mean, exactly, but nothing good.