A 3.9 magnitude earthquake struck 10 miles southwest of Topaz Lake on Thursday afternoon as part of a swarm that was going for most of the day.The largest of the quakes hit at 3:25 p.m. in Silver King Valley just north of Mineral Mountain in the Sierra above Antelope Valley, according to the University of Nevada's Seismological Lab.The quake was one of 25 reported by the lab. The swarm began early Thursday morning with a 3.7 magnitude earthquake, which occurred at 12:21 a.m. The rest of the earthquakes were between magnitude 1 and 2.In November 2010, a smaller swarm of …