Eastern face of Sierra Nevada’s long overdue for earthquake

This earthquake “drought” in the region has given rise to the public’s misconception that they are relatively safe and at low risk of experiencing an earthquake, says Nevada Seismology Laboratory Director Graham Kent.

Kent discussed the earthquake “drought” and the details of his latest research on Tuesday at the Earthquake Economic Resiliency Forum ahead of the Seismological Society of America’s annual meeting running Wednesday to Friday in Reno reports KCBS.

The Sierra Nevada in California is bounded on the east by a great fault scarp that produced a magnitude 8 earthquake in 1872. The scarp rises over 10,000 feet.

University of Wisconsin, Green Bay

Kent said a magnitude 6.0 or larger earthquake strikes along the Sierra’s frontal fault system that runs from south of Yosemite National Park to the north of Reno and Lake Tahoe every 10 years or so. There were seven 6.5 magnitude or greater earthquakes along this fault from 1915 to 1954, but there have been none since that time. He did add that a magnitude 6.0 quake struck 22-years ago in the Carson Valley south of Carson City, Nevada.

Kent urged the audience to use this period of no earthquake activity to work on preparedness before the next one does strike. It is worth noting that according to FEMA, a 6.0 magnitude earthquake could cause up to $1.9 billion in damage in the Reno-Sparks area and $590 million in the populated area of South Lake Tahoe, California, according to Phys.org.

“Let’s take advantage of this extraordinary quiescent period in our earthquake history,” Kent said. “We have a great opportunity to bring experts together with our community—those who need to put plans in place not only for disaster response but, just importantly, a plan for quick economic recovery.”

Although buildings of wood-frame construction fared relatively well in the earthquake, the back wing of this house collapsed. (1872 Owens Valley Earthquake.)

USGS

The largest quake ever recorded along the Sierra fault line was the 1872 magnitude-7.4 earthquake in Owens Valley south of Yosemite National Park. It is still ranked third behind the magnitude-7.9 at Fort Tejon in 1857 and the 7.8-magnitude in San Francisco in 1906. However, Kent says new research on the 1872 quake puts it at being larger than the 1906 earthquake that hit San Francisco.

Naturalist John Muir was visiting Yosemite in 1872 when the earthquake struck.He wrote about the experience in a way that is not used to describe earthquakes today: “I ran out of my cabin near the Sentinel rock, both glad and frightened, shouting, ‘A noble earthquake!’ ” Muir wrote. “The shocks were so violent and varied and succeeded one another so closely, one had to balance in walking as if on the deck of a ship among the waves.”