ITHACA, N.Y. -- As small earthquakes can be omens of larger ones and landslides can be precursors to avalanches, Cornell University geologists have shown in a computer simulation that forest fires display the same natural behavior. Their findings, they believe, could be used to predict where large forest fires can occur -- and how to prevent them.
The researchers' findings appear in the latest issue of the journal "Science "(Sept. 18, 1998).
"What is surprising to me is that an event like a forest fire is so similar to other natural events," says Donald L. Turcotte, the M.M. Upson Professor of Engineering in the Cornell Department of Geology. "And humanity really plays a small role in these events."
Turcotte and his fellow researchers, Bruce D. Malamud, a Fulbright Scholar and visiting lecturer in geology at Cornell, and Gleb Morein, a Cornell graduate student, built their computer model of forest fires and analyzed data sets from a number of forests and wildfires from around the world, including Yellowstone National Park.
Until 1972 Yellowstone had a policy of suppressing forest fires. This resulted in a large accumulation of dead trees, undergrowth and very old trees that became perfect tinder for fires. The researchers contend that the large Yellowstone fire of 1988, which burned 800,000 acres, could have been prevented if the policy of letting smaller fires burn to completion had been in place before 1972. The smaller fires would have eliminated the underbrush and dead wood earlier, thus reducing the likelihood of a large fire, they say.
In analyzing how forest fires start and propagate, the researchers found that the frequency distribution of small and medium fires can be used to assess the risk of larger fires, as small tremors are routinely used to assess the risk of larger earthquakes.