Zombie fires? Why Nova Scotia's dry fall could cause blazes to spark back up next spring
Dry conditions could make for some 'extreme fire behaviour' in 2025, fire chief warns
A Nova Scotia fire chief is warning that the province hasn't seen enough rain this fall to properly saturate the ground before the winter freeze, which could cause underground fires to smoulder and resurface in spring.
Fires that smoulder below the surface in winter are sometimes called "zombie" fires, but experts tend to prefer the more specific and less ominous terms of "overwintering" or "holdover" fires.
Brooklyn Volunteer Fire Department Chief Brett Tettanish spoke to the CBC's Information Morning Nova Scotia about the phenomenon and how it's not something we typically deal with in Nova Scotia.
The interview has been edited for clarity.
Tell us about underground fires and when they happen.
There hasn't been a significant amount of precipitation to really penetrate through the top layer [of the ground], which we call the fine fuel layer. With that, if someone were to have a campfire or burn brush or some type of fire that was able to develop a significant amount of heat, they may be able to ignite the layer beneath the surface. Once the fire gets under there, it will travel underground and resurface. Probably most of the fires that would start at this time of year would likely be out before the fire season in 2025, but there is a possibility that those fires can overwinter and then pop back up in the spring when conditions dry out again.
So the fires can continue to burn all winter?
Yes. It just kind of smoulders underground. As long as it has fuel and just a tiny bit of air in the ground, it will smoulder and then it can potentially resurface in the spring. It's unusual for Nova Scotia for that to happen. Often times, in Western Canada and western U.S., fires will overwinter and resurface. That being said, we've seen some unusual fire conditions here in 2023, so that's not to say that we couldn't have this happen here.
Your department responded to a fire recently that was quite deep into the ground. Can you tell me about that?
It appeared that there was a campfire that maybe hadn't been fully extinguished. At this time of year, people don't really think that that fire will spread. In this case, it appeared that it was hot enough that it ignited peat and roots below the surface and the fire burned in some cases three feet deep into the peat layer.
So it got bigger underground?
Yes, absolutely. As long as it has fuel, it will continue to burn underground unless the soil becomes well saturated or we put the fire out.
Where was this particular fire?
This was in an area of West Hants called King Lake. There are a lot of ATVs that would travel through the area. It was an ATV operator that discovered the fire and led us back to the fire. There have been multiple fires across the province this fall and it's unusual for this time of year. So we were quite surprised to see the depth in the ground that the fire burned.
How can people protect their homes?
If you burn wood, it's convenient to have the woodpiles stacked close to your home, but it's best to get those out of the immediate zone around your home and move them further away. Make sure your gutters are cleaned. Take a look at the FireSmart program. There's a short online course that the homeowners can do to understand what FireSmart is and how they can protect their homes and properties.
How crucial is it that we get a good significant rainfall?
If we don't get some significant rainfall, we could be in for some extreme fire behaviour in the 2025 season. I don't want to alarm people, but be prepared and it's best to look at the FireSmart program and how you can protect your home.
With files from Information Morning
