Nature
PUBLISHED
As monstrous winter storms rip through large parts of North America, the online rumor mills are blustering with reports of “exploding trees” in parts of the US. Rest assured, the risk of self-detonating vegetation is overblown. However, the hearsay is based on a real phenomenon you might actually hear and see in this season's deep chill.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Over the past few days, dozens of US states have issued severe weather warnings, as a series of weather systems has delivered feet of snow across the Great Lakes and Northeast, widespread icing from the Mid-Atlantic into the Southeast, and record-setting chill across the Southern Plains.
Along with power outages and travel chaos, some forecasters have pointed out a more unusual hazard lurking in the woods.
When temperatures quickly plunge, it can cause the water and sap inside trees to freeze rapidly. Since water expands as it turns to ice, pressure rises inside the tree. Under the right conditions, this can cause the bark to splinter with a thundering crack that sounds a bit like a rifle shot, hence the nickname “exploding trees” or "frost crack."
The effect will occasionally cause tree branches to suddenly fall and whole trunks to collapse, which is dangerous, but the phenomenon isn't always as violent as the name suggests. Instead of trees blowing up in an explosive outburst, it generally results in vertical fractures appearing down the tree trunk, especially in species with thinner bark.
As for the viral clips, some videos claiming to show “exploding trees” are AI-generated or don’t actually depict frost cracks at all.
A viral post on social media claimed there were forecasts for exploding trees across the Midwest and Northern Plains over the past weekend. However, certain state authorities have come out to say the risk of literal explosions is virtually zero.
“You may have seen a post circulating about the possibility of trees in Minnesota exploding due to plummeting temperatures. Luckily, there's no need to stay out of the woods to avoid this risk,” the Minnesota Department of Natural Resources said on Facebook.
“Our forest health experts explained that our native trees are adapted to Minnesota's weather, including below-zero temps. What you may hear are the boom or pop of 'frost cracks', which are vertical cracks in the wood caused by rapid temperature drop when the water and sap in the phloem and xylem freeze and expand. Trees with thin bark, like maples and birch, may be more susceptible, but the damage is rarely deadly to the tree,” they added.
But let’s not be complacent. While detonating flora is rarely dangerous to people, the extreme cold driving these rumors can pose real, immediate dangers. As of 16:30 pm UTC, January 26, at least 17 people in the US have reportedly died in this latest bout of extreme winter weather, and that figure is set to rise.
If you happen to hear the woods "firing off" this week, take it as nature’s alarm bell to stay inside, stay warm, and stay safe.
