Tag: Napa

California overdue for major earthquake

Three fault segments running beneath Northern California and its roughly 15 million people are overdue for a major earthquake, including one section that lies near the dams and canals that supply much of the state’s water, according to a geological study published Monday.

The three fault segments and one other in the region are loaded with enough tension to produce quakes of magnitude 6.8 or greater, according to a geological study published Monday.

They include the little-known Green Valley fault, which lies near key dams and aqueducts northeast of San Francisco. Underestimated by geologists until now, the fault running between the cities of Napa and Fairfield is primed for a magnitude-7.1 quake, according to researchers from the U.S. Geological Survey and San Francisco State University.

The water supplies of the San Francisco Bay Area, Southern California and the farm-rich Central Valley depend on the man-made water system that links to the Sacramento and San Joaquin rivers, noted James Lienkaemper, the U.S. Geological Survey geologist who was lead author of the study. The Green Valley fault is last believed to have ruptured sometime in the 1600s.

All four vulnerable fault segments belong to the San Andreas fault system, the geological dividing line that marks where the western half of California shifts northwest and away from the rest of North America at about 2 inches a year.

Source: AP

California hit by largest quake in 25 years

Over 80 people were treated at hospital and massive power outages were reported in North Bay area of San Francisco and around the city of Napa, after California was shaken by a 6.0 magnitude earthquake.

The 6.0 quake struck at 3:20 am (10:20 GMT), the US Geological Survey said. Its epicenter was 6 kilometers from American Canyon and 9 kilometers from the city of Napa, at a depth of 10.8 kilometers from the surface.

Residents of the cities of San Francisco, some 40 miles away, and Davis, just over 70 miles away, quickly took to Twitter reporting feeling the quake.

Three people – two adults and one child – sustained critical wounds. At least 87 people were treated for minor injuries at Napa hospital after the earthquake, the spokesperson told AP. Most patients have cuts, bumps, bruises, said Vanessa DeGier, spokeswoman for the hospital in Napa.

The quake caused six significant fires including a blaze at the Napa Valley mobile home park, where 4 trailers were completely destroyed, according to local firefighters.

“There’s collapses, fires,” said Napa Fire Capt. Doug Bridewel. “That’s the worst shaking I’ve ever been in.”

The city government said there were 50 gas main breaks and 30 water main leaks. Three historic buildings in Napa were also damaged, including the county courthouse, and at least two downtown commercial buildings were severely damaged.

At least 15,000 customers were left without power across Northern California, the utility provider Pacific Gas and Electric Company’s map showed following the massive quake.

The USGS initially measured the tremor as “moderate,” but then it was upgraded to “violent.” The immediate hours after the event saw at least five aftershocks measuring at 1.6 magnitude. Aftershocks of up to 5.0 magnitude may continue throughout the next week.

Source: RT