An earthquake shook the central coast on Friday. The temblor struck just over 3 miles southeast of San Juan Bautista at about 6:15 p.m. According to the USGS the quake measured 3.9 on the Richter scale at a depth of just over 3 1/2 miles. A second smaller 2.6 magnitude earthquake took place on Saturday at 4:42 p.m., about a mile east of Morgan Hill. No damages or injuries have been reported from either quake.