CAIRO, Ill. – Some southern Illinois residents might have experienced a slight jolt Thursday morning due to a minor earthquake.

A 2.4-magnitude earthquake happened around 6:15 a.m. Thursday, near Cairo, Illinois. The earthquake was tracked with a depth of six kilometers.

Cairo, Illinois is nearly two-and-a-half hours south of St. Louis, near the Missouri bootheel and Illinois-Kentucky state line.

The New Madrid Seismic Zone, which includes southern Illinois and adjacent states (Missouri, Kentucky, Arkansas), is the most seismically active area in North America east of the Rocky Mountains. 

There are an estimated 1.3 million minor earthquakes (2.0 to 2.9 magnitude) per year around the world, according to the United States Geological Survey.