Global warming fractured the bottom of the Arctic Ocean?
Yeah, that's the part I find hard to believe. The water there is slightly less than 32 degrees 365 days a year. How does that melt these methane hydrates at the bottom of the ocean?
Doesn't need to melt, as methane hydrates aren't really frozen. A lowering of pressure can cause methane release, which is what would happen, if the upper layers warmed and the water became less dense.