Some of these larger releases are due to shifting along the ocean floor in the arctic, exposing previously buried hydrates.
There has been some success in drilling into these formation to produce the methane, but it is still new and the technology is being developed.
http://www.freerepublic.com/focus/f-news/2436650/posts
http://www.freerepublic.com/focus/f-news/2455581/posts
The potential for this source is very large, if it can be economically developed. The recent successes in the shale gas production have postponed most of the interest in methane hydrates for the time being.
