More than 17,500 earthquakes were recorded in 2015 by the University of Nevada, Reno's Nevada Seismological Laboratory.

That includes the 231 recent quakes in South Reno and the magnitude 4.8 in Caliente that shook Las Vegas in January 2015, according to a Thursday report from UNR.

The biggest source of shakes is the so-called Sheldon sequence in far northwest Nevada, according to the seismological lab.

In 2015 there were 4,511 earthquakes recorded in the remote Sheldon Wildlife Refuge near Vya, east of Cedarville, Calif.

Other quake-prone areas in 2015 were Caliente, Carson City and Virginia City.

Outside of the persistent Sheldon sequence, Nevada was hit with 54 magnitude 3 or greater earthquakes - or about one per week all year.

"The south Reno swarm that just happened produced about 30 earthquakes in two days and about 200 more in the days that followed," said Graham Kent, director of the lab, in the news release.