How the Earth Catches Fire

Some time ago, we shared a few weird facts about the Earth, but the planet still has many feats in store that never cease to amaze us. The latest is its surface's weird ability to catch fire. Well, not really at random, as the catalysts of the peculiar process seem to be landslides. Following a series of this type of events, a recent study demonstrated that, given the proper conditions, a landslide can actually ignite.

In the hot summer month of August 2004, several teams of firemen dealing with a wildfire that burst close to Santa Barbara in California managed to identify its source in a recent landslide nearby, but could not explain what exactly generated the blaze. Some weeks after the event, a team of geologists from the US Geological Survey in Menlo Park, California, led by Robert Mariner, arrived at the location.

 

The crew discovered that the rocks in the landslide area were sufficiently hot (over 300 °C) in order to provide a proper environment for a fire. The measurements they performed on the air heat and composition in the boreholes indicated that volcanic activity and the emission of flammable natural gas could be eliminated as the possible source of the fire. That left them with the chance that the event was caused by a chemical reaction involving the rocks.

 

Their conclusions suggest that the landslide caused a mineral named pyrite to be exposed to the influence of the air, determining an oxidation reaction which heated a lode of low-grade coal in the vicinity up to the high temperatures that sparked the fire. According to Ian West from the UK-based University of Southampton, this type of fire appears more often than we'd think. "There have been a few along the UK's Dorset coast in the last few hundred years, and there are records of a huge fire in the Dead Sea area, dating from King Solomon's time, which may have started this way," he explained, as quoted by New Scientist.