Mine fire
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A mine fire is the underground smouldering of a coal mine. Such fires have economic, social and ecological impact.
Mine fires can burn for very long periods of time (months or years), until the seam in which they smoulder is exhausted. They propagate in a creeping fashion along mines shafts and cracks. Because they are underground, they are extremely difficult and costly to reach and put out. There is a strong similarity between mine fires and peat fires.
Some fires along coal seams are natural occurrences. Some coals may self-ignite at temperatures below 100 °C (212 °F) in the right conditions of moisture and grain size. Wildfires (lightning caused or others) can ignite the coal closer to the surface or entrace, and the smouldering fire can spread through the seam, creating subsidence that may open further seams to oxygen. Prehistoric clinker outcrops in the American West are the result of prehistoric coal fires that left a residue that resists erosion better than the matrix, leaving buttes and mesa. "Scientists estimate that Australia's Burning Mountain, the oldest known coal fire, has burned for 6,000 years," (Kevin Krajick, reported in Smithsonian Magazine).
Mine fires may begin as a result of an industrial accident, generally involving a gas explosion. Historically, some mine fires were started when bootleg mining was stopped by authorities, usually by blowing the mine up. Many recent mine fires have started from people burning trash in a landfill that was in proximity to abandoned coal mines (e.g. Centralia).
Globally, thousands of inextinguishable mine fires are burning, especially in China and India, where poverty, lack of government regulations and runaway development combine to create an environmental disaster. Modern strip mining exposes smoldering coal seams to the air, revitalizing the flames. (Krajick 2005)
Among hundreds of mine fires in the United States, the most publicized is in Centralia, Pennsylvania, which has been burning since 1962. Other mine fires in the United States burning today include a fire in Vanderbilt, Pennsylvania, the state with the most mine fires.
Rural Chinese in coal-bearing regions often dig coal for household use, abandoning the pits when they become unworkably deep, leaving highly combustible coal dust exposed to the air. Mapping China's coal fires from satellite photography discovered many previously unknown fires. There have been a few successes: in 2004, China ended a mine fire at Liuhuanggou colliery, near Urumqi in Xinjiang province. It had been burning since 1874. The worst of the current fires are in the Wuda coalfields of Inner Mongolia. China's coal fires burn 20 – 30 million tons of coal a year (Krajick 2005).
Contents |
[edit] List of mine fires
[edit] See also
[edit] External links
- "Coal fires - A natural or man made hazard?" (site about coal mine fires from Anupma Prakash, of the Univ. of Alaska-Fairbanks)
- Centralia, Pennsylvania Mine fire
- Centralia Mine Fire (from roadsideamerica.com)
- Welcome to Centralia
[edit] References
- Kevin Krajick, "Fire in the hole," in Smithsonian Magazine May 2005 pp 54ff.
- Kuenzer, C., Zhang, J., Tetzlaff, A., van Dijk, P., Voigt, S., Mehl, H. und Wagner, W.:Uncontrolled coal fires and their environmental impacts: Investigating two arid mining regions in north-central China. In: Applied Geography, Vol. 27, 2007, pp. 42-62, 2007.
- New Scientist, "Satellites track the fires raging beneath India" in Newscientist Website 18 July 2006
