A magnitude 6.0 earthquake centered near Napa shook Marin residents early this morning, but caused no reported damage in Central Marin, according to the Central Marin Police Department.
According to the U.S. Geological Survey, the earthquake, which occurred at 3:20 a.m. this morning 5 miles from Napa near the North Shore of San Pablo Bay, is the largest to hit the Bay Area since the infamous magnitude 6.9 Loma Prieta Earthquake of 1989.
The Associated Press reported that Governor Jerry Brown has declared a state of emergency for Southern Napa County, as buildings in the area were damaged, six fires broke out, water and gas pipes leaked, and 120 citizens were sent to a local hospital. The tremor also caused road closures along Interstate 80 and Route 37 near Vallejo and Sonoma.
The quake was located between the Hayward-Rodgers Creek Fault system and the Concord-Green Valley Fault system, both of which are within the larger San Andreas Fault system.
Both systems have not generated major earthquakes in many years—the Hayward-Rodgers Creek Fault last generated a major earthquake in 1898, and the Concord-Green Valley Fault generated a magnitude 5.5 earthquake in 1954.
Senior Annie Williams’ grandparents have a house in Napa, and she said they felt the earthquake’s impact.
“They called us at 3:30 and their entire house was shaken and they were awoken and the bedroom mirror completely fell over onto their bed and their china cabinet fell,” Williams wrote in an online interview. “A lot of memories and things that meant a lot to them are missing—they are both fine, just really shaken up about it.”
A number of small aftershocks did occur, and the USGS predicted this morning that the probability of an aftershock with a magnitude over 5.0 occurring in the next seven days is about 45 percent. About 25 to 60 small aftershocks between magnitudes 3.0 and 5.0 are expected within the same time frame.