Explainer’s Wildfire Roundup

Your questions about the disaster in Southern California, with answers from our archives.

A firefighter at the Sylmar Fire in Sylmar, Calif.

Three wildfires have been moving through Southern California in the past week, burning though 17,000 hectares of land, causing “the worst loss of homes due to fire” ever in the city of Los Angeles, and adding considerably to the state’s financial woes.

Among the firesburning in Southern California were the Montecito Tea Fire, the Sayre Fire, and the Triangle Complex Fire. Who picks these names?

In general, naming rights go to the group that makes the “initial attack” on a fire, whether it’s a squadron of local firefighters or a team from the U.S. Forest Service. (In contrast, every tropical storm in the Atlantic gets its name from a single organization.) The commander on the scene often uses a nearby geographical feature to describe the fire, but he’s not bound by any official rules. (For more on how a wildfire gets its name, read this Explainer from 2005.)

Officials have 100 percent “ contained” two out of the three fires. What does it mean to contain a fire, and how is the percentage calculated?

To prevent a blaze from spreading, firefighters dig a “fire line” around its circumference. If three miles of fire line have been built around a fire that is 10 miles in circumference, then 30 percent of the fire is contained. Once a fire is fully contained, firefighters work on “controlling” it by battling it inside the containment line. A controlled fire is one that has no risk of expanding beyond the fire line. (For more on how wildfires are rated, read this Explainer from 2001.)

According to newspaper reports, 1,500 California prison inmates are helping to put out the blaze. Why are prisoners fighting wildfires?

In California, some prisoners get transferred to a system of “conservation camps,” where more than 4,000 inmates are housed and trained to fight forest fires. According to the Department of Corrections, “assignment to a conservation camp is a hard-won privilege” and provides the opportunity for prisoners to live without gun towers or security fences and to reduce the duration of their sentences by as much as two-thirds. Spots at the camps are reserved for physically fit offenders with no history of escape attempts, violent crimes, or—naturally—arson. (For more on prisoners and disaster relief, read this Explainer from 2005.)

Gov. Schwarzenegger’s finance spokesman says wildfire property damagewill top $305 million. What about the environmental damage from all the carbon being spewed into the atmosphere?Do wildfires have a significant impact on global warming?

A lot depends on what the fire destroys, as there is tremendous variation among tree species in terms of carbon storage. If you see a fire sweeping through an expanse of mighty evergreens, the carbon emissions will be much higher than if the conflagration were consuming wispier trees. You’ve also got to factor in the composition of the ravaged soil. The fires that swept across Indonesia in 1997 burned relatively thin tropical trees. But the devastated forests were also covered in carbon-rich peat. As a result, the Indonesian fires were estimated to have released between 13 percent and 40 percent of the world’s annual emissions at the time. (For more on the environmental impact of wildfires, read this article from 2007.)

Santa Barbara, Calif., Sheriff Bill Brown says one of the fires was caused by a bonfire built by students, but the other two are still under investigation. How do you examine a wildfire for signs of arson?

First, figure out where it got started. The place where firefighters first engaged with the blaze is a good place to begin, as are spots where eyewitnesses say they first saw flames or charred ground. Once there, investigators can lay down something like an archaeological grid and start sifting through the debris. This evidence might include the “puddle” burn patterns caused by an accelerant—or the remains of a cigarette. Investigators also look for footprints or tire marks, and they sometimes use magnets to find stray bits of metal that might have been part of a time-delayed incendiary device. (For more on how investigators look for signs of arson, read this Explainer from 2006.)

Just this week, a homeless man in California was sentenced to four years in prison and ordered to pay costs of $101 million for setting fires that burned down 160,000 acres of national forest. How’s a guy who sleeps in a tent supposed to pay $101 million?

He isn’t. Instead, he’s expected to pay a tiny bit every month until he dies. The man, Steven Emory Butcher, currently receives $1,000 a month in Supplemental Security Income, which is basically welfare for the elderly, disabled, or blind. The federal court ordered Butcher to pay $25 to Los Padres National Forest four times a year while in prison, then $50 a month once he’s released. No one expects him to deliver the entire $101 million—even a spokesman for the prosecutor acknowledged that the odds of Butcher paying it off were “extremely slim”—but they do expect him to pay what he can. If Butcher gets a job when he’s out of prison, the probation officer can modify the amount of monthly payments—the criminal equivalent of refinancing your mortgage. (For more on why a homeless man is given such an unrealistic fine, read this Explainer from 2008.)

Witnesses have described “ thick clouds of gray-black smoke” blotting out the sun. Others have seen “ orange-white plumes.” What determines the color of smoke?

The type of fuel and how hot it’s burning. A wildfire can produce both colors of smoke. First, the hot, flaming combustion of dry underbrush releases little particles of black soot into the atmosphere. But the blaze also produces smoldering combustion—think of the glowing logs at the bottom of a campfire—which don’t burn quite as hot. Big branches or tree trunks that have a lot of moisture are more likely to smolder and release white smoke. (For more on what determines smoke color, read this Explainer from 2006.)

Reports have described wildfire flames as high as 100 feet in some places. How high can a fire hose shoot?

Between 75 feet and 100 feet straight up, depending on water pressure. In practice, though, firefighters on the ground rarely attempt to reach higher than 40 feet with hoses. (For more on how firefighters attack tall flames, read this Explainer from 2004.)

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