Lightning: fulgurites

Did you know a bolt of lightning can travel at speeds of up to 220,000 km/h and reach temperatures approaching 30,000 °C? Sometimes through this amazing process, lightning can have an effect on the earth it hits in the form of a fulgurite.

But what exactly is this alien sounding thing? Fulgurites are thin, hollow tubes formed in sandstone or soil with a high sand content, when the ground is struck by lightning. The extremely high temperature of the lightning instantly melts the sand particles and fuses them together. These tubes indicate the path the lightning took and can be up to a few metres long; they can also be quite fragile and must be handled with care.

Fulgurites can be created anywhere where there is sandy soil. A good place to find them is in the desert areas of the American Southwest where sandy soil and lightning are common, and there is a little vegetation.  Grasses and vegetation often obscure or hide the fulgurites, making them difficult to find.  

Want to know what they look like? Take a peek at the two examples below:  

A photo of a fulgurite taken end on. The hollow portion indicates the path of the lightning through the sandstone.  The intense heat of the lightning has melted the surrounding soil. Photo copyright Environment Canada


A photo of a Fulgurite that measures 7 cm in length. Photo copyright Environment Canada

Page details

Date modified: