AFTER 50 YEARS OF BURNING: WHAT WE'VE LEARNED FROM THE CENTRALIA COAL FIRE

The coal fire at Centralia, PA has been burning for the past 50 years, and though it has been recognized by many as a tragic legacy related to subsurface coal mining, it has provided an incredible laboratory for geoscientists and students. It provides topics of discussion on government intervention in environmental disasters and government politics, geology and health, geoscience education and public awareness, the history of anthracite coal mining and role of immigrants, etc. Additionally, one can discuss cyclothems and Pennsylvania in the Carboniferous, structural geology and tectonics, current greenhouse gas emissions from the combustion of coal, how coal fires work/convestion/conduction of heat, subsidence related to precipitation and mined-out coal, acid mine drainage, gas vent minerals and the minerals associated with coal, and how coal mining is conducted. Also, one can discuss the changes in heated soil, thermophillic microbes, wholesale changes in the ecosystem due to tallus piles, and primary and climax succession of surrounding vegetation. Finally, one can use the energy producing wind turbines to compare and contrast sustainable green technology with the remaining subsurface fossil fuels.

After 50 years, the coal fire at Centralia has evolved over time and evokes mystery and conspiracy, which is why there is still so much interest in it. On any given weekend, tourists from around the country visit it, television programs continue to focus on the ghost town, and scientists still study aspects of it. Over just a few years, the temperature of the fire has decreased from 450 C to 65 C, it's rate of movement has slowed to nearly a stop and now vegetation is returning to cooler soil, prompting some to question whehter the fire is going deeper into the subsurface or self-extinguishing. Though the fire appears to be greatly changing, it's likely that we will continue to learn even more from this outdoor laboratory.