14 DAY TRIAL // There is this town in central Pennsylvania, US, that's been on fire for over 5 decades now. Some maps don't even show it any longer, seeing how it has a population of just a dozen or so people and is, therefore, considered abandoned, but it's there all right. Well, whatever is left of it.
The forgotten town, named Centralia, was once a thriving mining community. Back in 1962, however, a fire ignited and gradually engulfed the coal veins running beneath it.
How it was exactly that the blaze that's been burning under Centralia for 53 years started is a puzzle that is yet to be solved. Some say it all began when somebody made the mistake to set fire to a pile of trash a wee too close to the entrance of a mine and the flames spread beyond control.
All efforts to put it out failed
When the underground fire that eventually brought about Centralia's demise started in 1962, authorities did their best to put it out. They poured loads of water into the blazing mining tunnels and they even tried to choke the flames using wet sand.
All of their efforts failed and so they eventually gave up. What with toxic fumes rising from the ground and sinkholes opening without warning, people moved away and Centralia became an abandoned town.
In a new episode of their series Reactions, scientists with the American Chemical Society explain why it is that, 53 years since it began, the fire under the town of Centralia is still burning and will very likely go on burning for many decades to come.
We've already talked about how, in order to burn, a fire needs fuel, oxygen and heat. Although confined to mining tunnels, the Centralia blaze has no trouble getting the oxygen it requires to go on burning.
The heat the fire itself produces is enough to keep the combustion process going - once they start, all fires are basically a chain reaction - and, seeing how the Pennsylvania town sits on top of vast coal deposits, access to fuel is not an issue either.
In fact, this underground blaze is doing so well supplies-wise that it's spreading at a rate of about 75 feet (nearly 23 meters) per year. Besides, it's said it will go on burning for at least another 250 years.
Geologists and other scientists monitoring it say that, these days, the Centralia fire in Pennsylvania reaches a depth of approximately 300 feet (roughly 90 meters) and spans over an area of about 6 square miles (15.5 square kilometers).
Underground fires are not such an oddity
This might come as a surprise, but as it turns out, underground fires that go on burning for years and years are not such an oddity. Au contraire, there are plenty of such blazes that are now heating up landscapes all across the globe.
Some of these fires are nature-made. Still, there are also many that, like the Centralia blaze, were started by people digging for coal. It's in India and in China that man-made underground fires are most common.
