For how long can a fire burn? As long as it has sufficient fuel, oxygen and heat. In some cases, this can be a very long time. The world’s longest burning fire is thought to be Burning Mountain (also called Mount Wingen) in Australia. This fire has been burning continuously for an estimated 5500 years. The fire is fuelled by a coal seam that is located 30 meters below the surface. Coal seam fires occur around the world. Other well-known examples are Brennender Berg (Germany) which has been burning for more than 300 years, Smoking Hills (Canada) discovered in 1826 and Centralia (Pennsylvania, USA), which has been burning since 1962.
The environmental impact of coal seam fires is not well understood. Coal fires emit carbon dioxide, methane, carbon monoxide, mercury, and a variety of other toxic substances. One study estimates that coal seam fires around the world emit as much mercury as all coal fired power plants in the USA.
Steam coming from cracks in the road to Centralia
Coal fires may start due to spontaneous combustion as well as human action. The Centralia coal fire for example, reportedly started when trash was burned on a waste dump sited on top of an entrance to an abandoned coal mine.
Coal seam fire are notoriously hard and expensive to extinguish, because their underground location makes them hard to reach. Efforts to extinguish the Centralia coal fire were abandoned when the proposed efforts to extinguish the fire required a budget of USD 660M. It was deemed more economical to let the fire burn and to evacuate the town of Centralia. The more practical approach seems to be to identify and block coal fires in the early stages. Satellites are increasingly utilized for this purpose.
To receive informative posts like this one directly in your mail box, sign up to our newsletter.