M4.1 quake hits Napa, California – the strongest since last year’s M6.0
Magnitude 4.1 earthquake was registered by the USGS at a depth of 8.9 km (5.5 miles) in Napa County, California at 02:53 UTC on May 22, 2015. It is the strongest earthquake since August 23, 2014 when the region was hit by strong and shallow M6.0.Going back a bit further