Scientists have discovered that landslides are to blame for some of the wildfires. They believe that during a landslide certain chemical reactions may occur, and as a result the temperature of soil may reach 300 degrees Celsius (572 Fahrenheit), New Scien

The authors of the survey cite the example of the Californian wildfire in August, 2003. After the fire it was discovered that it had started on a mountainside where a small landslide had taken place.

Geologists said the landslide had uncovered a mineral called pyrite (commonly known as fool’s gold), which consists mainly of iron sulphide (FeS2). When exposed to air, it caused an oxidation reaction, which heated a nearby patch of low-grade coal to more than 300 degrees Celsius. 

The temperature of the rocks in the landslide was 307 Celsius, but that wasn’t enough to start a fire. However, analysis of gas from boreholes ruled out geological ignition sources such as volcanic activity or flammable natural gas, so it appeared that a chemical reaction in the rocks caused the ignition.

Though this version may seem exotic, researchers believe such causes of fires are much more frequent than most people may think, and there are susceptible regions in Great Britain as well as in the US.

Wildfires are practically an annual occurrence in California and previously they were believed to be the results of human action, whether deliberate or accidental.

For example, in October, 2007, a case was launched against a juvenile who was accused of starting the Buckweed Fire in South California. Los Angeles County Sheriff's Department claimed the boy, who was under 13 years old, was playing with matches and started a fire that devastated more than 38,000 acres. Sixty-three structures, 21 of them homes, were destroyed, and three civilians and two firefighters were injured. It was said the fire forced the evacuation of about 15,000 people.