Earth On Fire

Thousands of hidden fires smolder and rage through the world’s coal deposits, quietly releasing gases that can ruin health, devastate communities, and heat the planet.

Not far from Hazard, Kentucky, in the shadow of Lost Mountain, a woman named Ruth Mullins saw smoke rising off the slope. “I knew it wasn’t no woods on fire, because of the smell”—the rotten-egg stench of sulfur—she said. Her suspicions were soon confirmed: Lost Mountain’s coal mine, abandoned for 40 years, was burning.

Kentucky names coal fires for the people who first report them, so the fire, which has continued to smolder and occasionally flame since it was identified in 2007, is known officially as the Ruth Mullins fire. “We’ve never met the woman and we don’t know where she lives, but her name now appears in scientific publications that are read all over the world,” says Jennifer O’Keefe, a geologist at Kentucky’s Morehead State University. “She’s got her little bit of immortality.”

O’Keefe is part of a team that has been visiting the Ruth Mullins fire over the past three years, studying its behavior and quantifying the gases that plume from nine known openings in the ground. Last January she and a colleague, University of Kentucky geologist James Hower, brought some students to the coal fire for new measurements. They parked off Highway 80, a road that cuts a swath along the side of Lost Mountain, and unloaded gear in a stingingly cold wind as speeding trucks whipped ice along the asphalt. Trudging up the snow-covered mountain, the scientists shivered along the flat shelf of land circling its midsection, the remains of contour mining in the 1950s. While smoke from the burning mine had been hard to spot from the road, here it billowed from small vents where portals to the mine had collapsed.

Coal fires are as ancient and as widely distributed as coal itself. People have reported fires in coal beds close to the earth’s surface for thousands of years. Considered the world’s oldest coal fire, Australia's Burning Mountain in the Upper Hunter Region (right) is Australia’s only example of a naturally burning coal seam (one of only three in the world). Believed to have been naturally ignited about 6000 years ago, it’s slowly burning through a thick coal seam about 30m deep. The first non-Aboriginal observation of it occurred in 1828 when a local farmhand named Smart claimed to have found an active volcano. A year later it was correctly identified as a coal fire.

Ever since the Industrial Revolution, the number of coal fires has grown dramatically. There are now thousands of such fires around the world, in every country—from France to South Africa to Borneo to China—where mining exposes coal deposits.

These fires are an insidious, persistent, and often invisible threat to local health and to the natural and built environment. Added to that, there is now the growing realization that all these coal fires, mostly unknown to the general public, may be contributing significantly to climate change. To determine this the United States Geological Survey (USGS) has undertaken a study to measure the emissions of greenhouse gases and other pollutants from coal fires around the United States, beginning in Wyoming with three coal fires in the Powder River Basin (at right).

This effort includes scientists from organizations around the country who will use new tools and expertise to measure greenhouse gas emissions previously not included in existing national and worldwide surveys. They hope to ascertain the overall contribution of these coal fires to global warming in a quantitative analysis.

Most Americans are unaware of underground persistent coal fires except perhaps for the one in Centralia, Pennsylvania where in 1962 the inhabitants of the town not realizing the abandoned strip mine had not been properly sealed began to use the ground as a dump and burned trash there, thinking that once the trash was burned up and the embers put out that the fire was over. However, the fire continued to burn advancing along a fifteen foot long opening that connected to a maze of underground mine tunnels. These passages allowed the fire to spread to the coal underneath the town and expand along four fronts, eventually affecting a surface area two miles long and three-quarters of a mile wide.

Efforts over several decades to put the fire out have failed and the town finally gave up the fight with most of the residents moving away under a government relocation program. The fire continues to burn today moving through a vast network of abandoned mines which are still littered and lined with coal. The town of Centralia looks like a disaster zone and smoke from the fire billows out of the ground, lending a sulfurous stench to the air. In addition, there are sinkholes encased in sulfur throughout the town, trees laden with sulfur, huge cracks in the abandoned section of Highway 61 which goes to the town, and a ravine, named Death Valley, where thick fumes can be seen rising from the ground.

Glenn Strecher, a geologist at East Georgia College, studied the Centralia fire when he was newly graduated from graduate school. With a graduate student, he published his findings in the International Journal of Coal Geology in an article named "Coal Fires Burning Out of Control Around the World: Thermodynamic Recipe for Environmental Catastrophe". In the article he wrote that some of the sulfur from the underground coal fire (example at left) crystallized and stayed on the ground, part of the sulfur polluted the air, and some of the sulfur leached into the local water, contaminating it. His past study serves as the basis and inspiration for this current study by the USGS.

The Centralia coal fire is not the largest in America nor the oldest. It is not even Pennsylvania's oldest or biggest coal fire. The United States has 112 documented underground fires like Centralia and Ruth Mullins, along with many more yet to be counted. In addition to the underground coal fires, there are 93 surface coal fires, some of them in huge waste piles created during the process of coal mining. All this burning coal releases a wide range of chemicals, some of them toxic such as benzene, toluene, and xylene.

Coal fires, although mostly unseen beneath our feet, can have profound impacts on human health. A coal fire in Alabama caused traffic accidents. A coal fire in India is responsible for cases of asthma, chronic bronchitis, lung cancer, and skin cancer in that locality. The Ruth Mullins coal fire is slowly migrating towards Highway 80 where the state's Laura Campbell coal fire threatens the water supply. If a coal seam burns through the road, asphalt could crack open and sink, swallowing people and cars. So far, an effective method of extinguishing these coal fires has not been developed primarily from a lack of focus and a lack of funds. If the USGS finds that the coal fires are significant contributors to the greenhouse emissions of the US, perhaps the time has come when attention will be paid and efforts will be funded to put out the fires.

To read more from the original article, visit the Discover magazine site. The article from the July/August 2010 edition of the magazine can be read by non-subscribers for a small fee.

Source:
Discover, "Earth On Fire", accessed November 15, 2010