The Hazelwell coal mine in Victoria, Australia, ablaze for nearly a month now, has spewed enough poison into the air to prompt authorities from the town of Morwell to order an evacuation for babies, the elderly and those with compromised health. Masks have been distributed and further evacuations may follow.
The blaze is underneath the mountain of coal and periodically breaks through, despite four weeks of fire trucks spraying water on it. All of the water that has been absorbed into the coal mountain has also raised fears of landslides.
At the height of the fire, on Feb. 5, there were 80 firefighting apparatuses including tankers, ladder platforms and aircraft, according to the Country Fire Authority (CFA) in Victoria.
It's very challenging to put out a coal seam fire, especially one as hot as the one in Morwell. Gasses released, including carbon dioxide and carbon monoxide, are deadly to humans and the heat keeps firefighters from getting too close.
"You have to start with massive amounts of water from high pressure water hoses from a safe distance and once you can start to bring the temperatures down you can do other things to try to restrict the air access, University of Queensland mining safety expert Prof. David Cliff told ABC Science. "In the case of this Victorian fire it's a matter of an awful lot of water and maybe bulldoze dirt over it if you can get access to it."
Coal-seem fires often start accidentally through spontaneous combustion, but the one in Morwell is suspected to have been intentionally lit.
According to Cliff, coal seam fires are much harder to put out than wildfires. "Unlike timber, coal when it gets hot has massive thermal mass which is very hard to extinguish," he told ABC Science. "This Victorian brown coal is a low rank coal, geologically young, and very prone to being ignited. This is a thick-seam coal mine, 30 metres thick and very close to the surface so anything that intrudes into the mine will set fire to the seam."
Coal seam fires can burn for a long, long time, if there's enough coal there to fuel it. One of the longest-burning coal seam fires is at Burning Mountain in New South Wales, Australia. It has been burning, very slowly, for at least 6,000 years, reported ABC Science. Another long-burning coal fire is in Centralia, Penn., where the coal has been smoldering since 1962. Here, the Morwell fire starts to lose steam around March 3.