Deeper groundwaters residing in subpermafrost aquifers in Svalbard vent methane all year around through open system pingoes.

 

The emissions are locally significant although the dynamics of this release differ however with season. Hydrological and meteorological conditions regulate the evasion, and thus periodic outbursts of methane happen during winter with ice fractures, where most of the methane is accumulated.

In the summer, meltwaters tend to dilute the concentrations of methane and instead high levels of carbon dioxide can be observed. We found that the methane is mostly biogenic and produced in marine sediments that are located beneath coastal permafrost.

 

Subpermafrost methane evasion is still one of the least understood sources of the gas into the atmosphere.