2.1 quake detected in Union County, IL

A small earthquake was detected in southern Illinois early Monday morning.

The 2.1 magnitude tremor occurred at 2:52 a.m. in Union County near the Mill Creek community, 6 miles south of Anna-Jonesboro and 14 miles east of Cape Girardeau.

It's the first detected tremor in southernmost Illinois since a 2.2 quake was centered under the Ohio River at Olmsted on December 10.

A more active quake zone in Illinois has been south and west of Mt. Vernon, where three tremors of 2.3, 2.5 and 3.1 have been detected in March and April.

There was also a 3.6 quake last November north of Peoria.