Wednesday, December 1, 2010

Fault line could help fund county retrofit

New data adds to county’s application for federal funds


By KATHERINE WUTZ
Express Staff Writer

A recently discovered fault line runs for about 40 miles along the Sawtooth Mountains, above.

A previously unmapped fault line near Stanley may help Blaine County's chances of being awarded federal funding for earthquake preparation, a state official said yesterday.

The county is in the process of applying for a FEMA Pre-Disaster Mitigation Grant, which gives states funding to reduce potential disaster-related loss of life and damage. The county can apply for up to $3 million in federal funding to strengthen the county courthouse's structural integrity and ensure it would withstand a major earthquake. The county would be required to match 25 percent of the federal funds.

Blaine County was eligible to apply for funds due to its proximity to several major active faults, including the Lost River Fault, 50 miles northeast of Hailey, which caused the 1983 Borah Peak earthquake near Challis. That quake resulted in two deaths and extensive property damage.

The newly discovered fault line is also considered a major, active fault, running for about 40 miles along the base of the Sawtooth Mountains near Stanley and Redfish Lake. Though researchers believe seismic activity occurs once every few thousand years on the line, the fault is capable of unleashing an earthquake with a magnitude as high as 7.5. The Borah Peak earthquake had a magnitude of 6.9.

A seismic evaluation report done by Boise-based McClendon Engineering suggests that if such an earthquake were to occur, the 1883-vintage building would sustain severe damage. That could include partial or total collapse of the roof, separation of the stairway tower from the main building and possibly a collapsing of the second floor onto the first.

Mark Stephensen, mitigation officer for the Idaho Bureau of Homeland Security, said a note of the previously unmapped fault line has been included in the county's application, and that discovery of the fault line would likely impact the results.

"It's going to have to be considered," Stephensen said. "Any additional information that would indicate that the earthquake hazard is clearly present would increase the urgency or necessity of the project."

Still, Stephensen said, there's not a lot of time to add a detailed amount of information regarding the discovered fault line to the application.

"The deadline for the application is on Friday," he said. "We're getting ready to submit this thing."

The state Bureau of Homeland Security approves the projects before passing them on to FEMA for consideration. Char Nelson, the county's director of operations, said the county's application has been accepted by the bureau and will proceed to the next step.

"We at [the bureau] believe this project to be necessary," bureau spokesman Robert Feely said.

Feely said the application takes into account all currently available data, including the studies done of the Stanley fault.

According to Idaho State University geosciences Professor Glenn Thackray, researchers believe that the fault triggered two major earthquakes over the past 10,000 years. Thackray's theory that a major active fault ran along the base of the mountains was confirmed when a 2.1 magnitude earthquake occurred along the fault in late September.

Tremors from a 7.5 magnitude earthquake might be felt from Boise to Sun Valley, Thackray said. Though earthquake prediction is not an exact science, Thackray told a Reuters reporter, an earthquake on the fault is possible in the near future.

"There's a chance in the next few decades there will be an earthquake on this fault, and if it does happen, it will be a rather large earthquake," he said.

The results of the county's application won't be known for some time, Feely said.

"We can't speculate on the outcome of the national competitive process," he said. "[But] we definitely stand behind the county's efforts to protect its citizens."

A decision regarding the county's application is anticipated as early as the end of February.

Katherine Wutz: kwutz@mtexpress.com




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