Seven or eight flames constantly break out of the earth in a four-meter stretch in the Changshou area in southwest China. Regardless of the weather conditions, the fire there burns all year round. Residents of the neighboring village flock to the site twice a day to boil water or boil a dinner in five minutes.
“Firewood used to be expensive, and sometimes we had to go to the western mountain regions behind them. But here it is more convenient. We come here with our cooking pots and stand in line to cook dinner, “local resident Van Mantan told CCTV.
Underground fires occur around the world, both in areas with warm climates, such as China, and in cold ones such as Siberia. They are ignited by lightning, man, as a result of mining or spontaneous and can burn for decades.
“They are usually similar to each other, although the reasons for their occurrence may be different,” says Anupma Prakash, professor of geophysics at the University of Alaska Fairbanks.
In China, the cause of underground fires, as a rule, is coal, 62 deposits of which are scattered in the north of the country. The fire in Chongqing began to burn 59 years ago, when an oil exploration group drilled a well in a natural gas field. Workers left the well largely unexplored, and since then it has emitted an excess of gas, fueling the flame.
Pros and Cons of Underground Fire
The villagers have found a way to use fire in their own interests, in particular for cooking. Other communities have found a subterranean flame of creative use – for example, in Australia with its help created an attraction for tourists “The Burning Mountains.” But in general, according to Prakash, the negative aspects of these fires outweigh the positive ones.
Underground fire burns coal. As a result, the earth under pressure can fall into the depressions, taking large amounts of oxygen, fueling the flame. This can lead to the formation of landscape irregularities and dips.
Because of the hollow ground, cracks can form on the surface. Where there is fire and smoke, a toxic mixture of carbon monoxide, sulfur dioxide and coal dust rises from the ground, polluting the air. This not only worsens climate change by adding greenhouse gases to the atmosphere, but also damaging people’s health.
Also, these fires create economic problems. Chinese coal is pure anthracite, which makes it the best quality coal in the world. Underground fires burn fuel that could be used for more conscious and cost-effective purposes.
How to extinguish underground fire
All fires require three components – fuel, oxygen and heat. If you remove one of them, the fire goes out. Some communities are engaged in extinguishing underground fires, flooding them with a mixture of water and liquid clay or other natural materials. Others use swelling clay, which expands to cut off oxygen and drown out the flame. Liquid nitrogen is also used to extinguish underground fires.
How long will the fire burn in the village of Chongqing? It’s hard to say, but, apparently, Wang and his neighbors will be able to return to the natural fire for many years to come. “It can not be extinguished,” says Wang. “It burns every minute and every day throughout the year.”