I've attached an article from Reno's local newspaper, the Reno Gazette Journal. The article states that the swarm has been occurring since the end of February. Last night they had the strongest quake so far, a 4.7, and "the recent activity around Reno is unusual in that the quakes started out small and continue to build in strength. The normal pattern is for a main quake followed by smaller aftershocks." And "if the pattern continues we may be looking at a larger event in Reno," said Ken Smith, a seismologist at UNR.

"Reno’s last major quake occurred at 12:34 a.m. on April 24, 1914. The 6.1 temblor awakened people as far away as Sacramento, Calif., prompted people to rush out of Reno saloons and hotel lobbies into streets and toppled chimneys, said Craig dePolo, research geologist with Nevada Bureau of Mines and Geology."

• Quakes in Reno