Coal, fire, methane, and moving mountains

Carboniferous news meanderings and meditations

Investigators have yet to settle on a cause of the devastating Marshall Fire that tore through grasslands, strip malls, and housing developments outside of Boulder late last year. They have ruled out lightning and downed power lines, but continue to look into the possibility that it was ignited by a coal seam fire. That got me thinking about coal fires, about a moving mountain, and about environmentalists celebrating methane flaring, albeit not necessarily in that order.

At any given time thousands of fires smolder in abandoned and active mines and un-mined coal seams nationwide. Sometimes these subterranean blazes are sparked by lightning or wildfires. Other times air and water get into the seam catalyzing an exothermic reaction which causes coal spontaneously to ignite. They can burn for hundreds of years or even longer. Most go largely unnoticed. That is, until they do something that demands attention—like start a wildfire.

The Marshall Fire began near the abandoned Lewis coal mines near Marshall, where Colorado geologists first observed an active coal fire in the 1980s. It is not uncommon for the subterranean infernos to migrate to the upper world: In 2002 a coal seam fire started a 12,000-acre blaze near Glenwood Springs, Colorado, and at least one of last summer’s Montana fires has been traced back to a burning coal seam.

Sometimes the underground fires manifest in even more dramatic ways.