Sources of methane escaping from Arctic environments

Sources of methane escaping from Arctic environments into the atmosphere. Methane measured in the September 2017 test likely came from microbial breakdown of organic matter in gullies that cut into the permafrost (source 1). Other important sources are deep geologic deposits underlying the permafrost (source 2) and offshore methane hydrate, an ice-like combination of methane gas and water that is stable at low temperatures and moderate pressures (source 3).