“Zombie fires” smouldering under the snowpack in Canada since last winter have ignited as the weather heats up, contributing to an intense start to the wildfire season in large parts of Canada, scientists and fire experts say.
Scientists are studying the rise of the phenomenon, also known as overwinter or holdover fires, where the soil catches alight during summer and burns extremely slowly underground during the subsequent winter.
The rich organic peat and moss that is common in the boreal region helps keep the flameless blaze alive even under layers of snow. The snowpack instead insulated the fire, said Thomas Theurer, research fellow and a fire expert at the University of Aberdeen.