Twenty-seven small earthquakes struck the Verdi-Mogul area on Tuesday alone, according to the US Geological Survey.
No damage was apparent.
USGS says Tuesday's quakes ranged in magnitude from 1.0 to 3.4. The strongest quake, the 3.4, hit at about 8 a.m. The next strongest earthquakes measured: 3.0, 3.1 and 3.2 -- all striking around 2:30 p.m.
Geologists say the region began experiencing a sequence of earthquakes in February, and it is impossible to predict if a large quake is to come.