"Shallow deposits of frozen methane beneath oceans may be more vulnerable to thawing than previously known."
"The slowdown of a key ocean current could release methane that is frozen in layers of organic seabed sediments along some of the world’s coastlines, a new study shows.
Cold temperatures and high pressure on sea floors currently sequester about one-sixth of the world’s methane, a potent but short-lived greenhouse gas, in an ice-like form called methane hydrate, or clathrates. Sudden thawing of those clathrates could result in a surge of methane emissions that would spike the planet’s fever. The new research, published today in the Proceedings of the National Academy of Sciences, shows that some of the shallower layers in the Atlantic Ocean could be more vulnerable than previously thought to warming that could release that methane, and that such events have happened in the distant past.
The trigger for such warming and thawing, according to the study, is a large inflow of fresh, frigid water from melting Arctic ice, which can disrupt the Atlantic Meridional Overturning Current, a slow ocean heat pump, pushing cold water in the Arctic deep down and southward, and warm water to the surface and northward."
