UCSB Geology Professor Emeritus James Boles says that recurring fires on the cliffs near Hope Ranch are not caused by volcanoes or friction but by three simple things — organic material, iron sulfides, and air.
"These reactions are called exothermic reactions and they give off heat, and if you have a confined space and heat can build up to a point, it can cause combustion of the organic matter that's in the rock," Boles said.
He explains that oxygen finds its way through rock layers during the natural process of erosion, bringing air and sulfides together and resulting in temperatures rising to more than 450 degrees Fahrenheit, according to his research — a phenomenon he’s seen in soils around the world. Here on the Central Coast, we also have oil, which complicates things.
"It's in these fractures, in the case at Hope Ranch, the fractures are burning because of the tar that's in there," Boles said.
Fires near Hope Ranch occur every few years and seem to move with the land, according to Santa Barbara County Fire Department Captain Scott Safechuck.
Geological Event: Hope Ranch hillside, Santa Barbara. Fire isolated to plastic drainage pipe and surrounding vegetation. No structures threatened. Fire resources on scene. This is ongoing historical activity that flares up periodically. CT 12:36pm pic.twitter.com/x4Aa0ddAFD
— Scott Safechuck (@SBCFireInfo) August 18, 2024
"In the 25 years that I've been here, it's moved a little bit easterly some years and a little westerly in other years," Safechuck said.
And fighting these fires has its challenges.
"It is unique that when we put the vegetation out, the heat is still there," Safechuck said.
However, he says fires caused by exothermic reactions typically don’t cause property damage and are easily managed by local fire teams.
