Sentences with phrase «restricted by permafrost»
Unlike other terrestrial and marine sources, which gradually release methane as it forms, the shelf is emitting methane that has accumulated in seabed deposits for hundreds of thousands of years and until now was restricted by permafrost, says Shakhova.
http://environmentalresearchweb.org/ Not exact matches
As to the other query, pingos, by definition are restricted to permafrost regions, although one might note they can be found in the ocean where permafrost underlies the continental shelf.