A magnitude-3.2 earthquake shook the Napa region early Sunday, the latest and largest in a string of aftershocks that followed the 6.0 temblor that rocked the region on Aug. 24.
The U.S. Geological Survey classified the quake, which was felt throughout the Napa area at about 2 a.m., as light to weak in terms of shaking intensity. One Sacramento resident reported feeling the aftershock, which occurred 51 miles southwest of the city.
Justin Pressfield, a USGS spokesman, said no damage was reported from the latest shaker and that quakes of this magnitude do not typically cause any. Pressfield estimates that there have been about 80 aftershocks since the major quake last week, five or six of which have been in the low 3-magnitude range.
“This is the normal amount of aftershocks, and the intensity is actually less than we were actually thinking it could be,” he said. “After an earthquake of magnitude 6, there was a 50-50 chance of a magnitude 5, but as time goes on we’re seeing the lower earthquake aftershocks.”
Earthquaketrack.com shows that in the last 24 hours, 19 small aftershocks have been detected in the greater region that encompasses Napa and surrounding communities. The next-largest quake during that time was a magnitude-2.5 quake centered near Fairfield.
About 10 more small aftershocks are expected in the next 10 days, according to the USGS. Aftershocks are typically felt within days of the main shock but may be felt in the weeks or months afterward.
Call The Bee’s Sammy Caiola, (916) 321-1636.