O'FALLON, Ill. — People in O'Fallon, Illinois, reported feeling an earthquake Saturday morning.
The United States Geological Survey recorded a 2.4 magnitude earthquake at 1:50 a.m. Saturday.
The USGS said the earthquake was one kilometer south-southwest of O'Fallon, Illinois, at a depth of .3 kilometers.
Ten people had reported feeling the earthquake to the USGS.
The St. Louis region has frequent small earthquakes from the New Madrid Seismic Zone.
Seismologists can forecast the probability of an earthquake over the next 50 years, based on historical trends of previous earthquakes, but they can't predict exactly when they will happen. Current estimates for the New Madrid Seismic Zone forecast a 25-40% chance of a magnitude six or greater earthquake in the next 50 years and a 7-10% chance of a magnitude seven or greater in the same period.