ST. LOUIS—Southern Illinois was rocked by a 3.1 magnitude earthquake Monday morning. It happened about 12 miles north of Mount Vernon, according to the United States Geological Survey.
The quake happened about 10 miles underground and nearly 350 people reported feeling the tremors, some as far away as Arnold, Lake St. Louis, Edwardsville and even Springfield, Ill.
The earthquake happened in the Illinois Basin-Ozark Dome region, which borders the more active New Madrid seismic zone.
The USGS says earthquakes are frequent in the Illinois Basin region, with the largest one being a 5.4 magnitude quake in southern Illinois in 1968.
An 8.1 magnitude quake hit along the New Madrid fault on Dec. 16, 1811 and was felt as far away as Boston where church bells rang.
