And the structures that remain apparently release methane gas for some time — as is evidenced by continued high methane concentrations found at crater sites and by observed emissions from crater lake surfaces. (robertscribbler.com)
High methane concentrations in well - ice - bonded sediments and gas releases suggest that pore - space hydrate may be found at depths as shallow as 119 m. Geochemical and isotopic determinations suggest that the methane hydrate observed in the core hole is biogenic (microbial) in origin. (pubs.geoscienceworld.org)
So far our data do not show any evidence for rapid water contamination, as we do not see evidence of these diluted brines (type D water) associated with distance to natural gas wells (the Osborn 2011 paper) in wells where higher methane concentrations were observed. (dotearth.blogs.nytimes.com)