Exploding tree

Exploding trees occur when stresses in a tree trunk increase leading to an explosion. These explosions can be caused by three different factors: cold, lightning, and fire.

Causes

Cold

Cold weather will cause some trees to explode by freezing the sap, because it contains water, which expands as it freezes, creating a sound like a gunshot. The sound is produced as the tree bark splits, with the wood contracting as the sap expands.John Claudius Loudon described this effect of cold on trees in his Encyclopaedia of Gardening, in the entry for frosts, as follows:

Henry Ward Beecher records anecdotal evidence of the wood from which instrument cases and carrying boxes were made splitting in temperatures of −70 °F (−57 °C) in Captain Bach's travels near the Great Slave Lake. Linda Runyon, author of books on wilderness living, recounts her experience of the effect of cold on maple trees as follows:

Wally and Shirley Loudon reported the effect of the freeze of December 1968 upon their orchard in Carlton, Washington as follows: