Carson-area faults capable of triggering major disasters

RENO - Few people living in Nevada have experienced a major earthquake - the last magnitude 7 temblor struck the state more than one-half century ago. But it's not a question of if another will occur, but when, experts said Tuesday.

The potential county-by-county toll was detailed in a study released Tuesday by the Nevada Bureau of Mines and Geology.

The bureau's director, state Geologist Jonathan Price, outlined the study at the University of Nevada, Reno and made suggestions to help reduce the toll of a powerful quake. A similar presentation is scheduled for today in Las Vegas.

"There is something we can do about it now," Price said. "What is clear from earthquakes in California where there was a lot of preparedness is that lives can be saved and property damage can be minimized if mitigation steps are taken."

Using loss estimation models developed by FEMA, the state report estimates that a magnitude-6.5 quake along the Carson City fault could kill as many as 33 residents of the capital city and displace more than 1,000 households.

To the south in less populated Carson Valley, a quake of magnitude 7 is possible on the Genoa fault, and could kill as many as 27 Douglas County residents and leave as many as 400 households in need of shelter.

Damage estimates were based on the 2000 Census and on distribution of population provided by the state and county.

The number of people killed depends on what time the earthquake occurs. According to the scenarios, a 6.5-magnitude Carson City earthquake at 2 a.m. would kill an estimated 12 people, and 70 would require hospitalization, including six with serious injuries.

After a 2 a.m. magnitude-7 Genoa quake, nine people would be killed, and five would be seriously injured with a total 38 requiring hospitalization.

If the quake occurred at 5 p.m., there would be more critical injuries, mostly as a result of traffic accidents. The Carson City model predicts 33 deaths, 21 serious injuries and 112 moderate injuries. In the Genoa model, 27 would be killed, and 42 people would have severe injuries and 85 moderate injuries.

According to the model, at least 7,847 buildings in Carson City would be at least moderately damaged, or 48 percent of the total number of buildings in the region, with 918 buildings beyond repair. In Douglas County, 5,333 buildings would receive at least moderate damage, and 382 buildings would be damaged beyond repair.

The vast majority of these buildings would be single-family homes or other residential structures. Since most of the damage would be suffered by homes, the vast majority of the damage would be to wooden structures, with manufactured homes coming in a distant second.

Bridges would be hit hard, with two of Carson's four bridges and 13 of Douglas County's 29 bridges receiving moderate damage to total destruction.

Loss of basic utilities such as water and electricity would affect an even broader number of people. Fires, a frequent occurrence after major earthquakes due to gas-line ruptures, would displace additional families.

The costs to repair and rebuild could climb to more than $2.9 billion after a Carson City fault earthquake and $3.1 billion in Douglas County.

"There is a good chance that you will experience a major earthquake," Bureau of Mines research geologist Craig dePolo, a co-author of the survey, said. The likelihood is greater in the Reno-Carson City area than around Las Vegas, he added

While some measures such as retrofitting buildings are prohibitively expensive, commonsense preparations for an earthquake include removing heavy objects from shelves - especially over beds, anchoring shelves, attaching water heaters and furnaces to walls and using flexible gas connections.