A two-acre patch of land
north of Fillmore has heated up to 800 degrees, and firefighters and geologists
are unsure why.
A patch of land in Ventura County's section of Los Padres
National Forest where the ground recently heated up to 812 degrees continues to
puzzle firefighters and geologists after weeks of monitoring.
"It's a
thermal anomaly," said Ron Oatman, spokesman for the Ventura County Fire
Department.
Firefighters responded to reports of a blaze there a month
and a half ago, when observers noticed smoke rising from the parched scrub. But
when they arrived, they found no flames.
Firefighters and geologists who
have surveyed the area in the Sespe Oil Field are uncertain what's causing the
heat, but they do have a theory.
Allen King, a retired geologist with the
U.S. Forest Service who went to the site Friday, said the smoking ground is "a
normal occurrence" that does not appear to be the result of human
activity.
The hot spot is in an area considered to be an active
landslide that has shifted for more than 60 years. Several hundred feet below
its cracked surface lie pockets of gas, tar and oil.
King said he
suspects cracks along the landslide's slope allow oxygen to enter into the earth
and hydrocarbon material to "seep out" of the fine-grain shale. The combination
can create underground combustion, he said.
King said the depth at which
hydrocarbon material can be found "varies tremendously" and that he does not
know at what depth the combustion in the oil field is occurring. The 812-degree
temperature was measured Friday about a foot below the surface, he said. No
other temperature checks have been made since, according to
Oatman.
During Friday's visit to the hot spot, smoke rose through five
cracks in the ground. From a distance, it looked like "a small, smoldering camp
fire," Oatman said. The smoke comes and goes, he said, and fire officials expect
it will last until the next heavy rainfall, when water and mud plug the
fissures.
The steep, rugged terrain is owned by the U.S. Bureau of Land
Management and leased by Seneca Resources Corp. The area is gated off from
public access and is free of equipment and buildings.
The hot spot is not
considered to be a threat to public safety, Oatman said, and the Fire Department
is monitoring the area daily.
The 3,000-acre Sespe Oil Field was
discovered in 1887 and has since produced about 50 million barrels of oil, said
David Christy, spokesman for the Bureau of Land Management. The field contains
more than 300 oil wells, 210 of which are active. In January 2007, about 200 to
300 gallons of oil spilled into a nearby creek after a pipe containing a mixture
of groundwater and oil burst.
Jeff Kuyper, executive director of Los
Padres ForestWatch, said he had not heard of hot spots in the oil field but was
concerned about their potential effect on the nearby Sespe Condor Sanctuary and
the forest's fire-prone nature.
"It's just a disaster waiting to happen .
. . regardless of what the cause is," he said.
joanna.lin@latimes.com