Mystery Tremor Rattles Eastern Illinois on Thursday

If you felt an odd shake in the eastern part of Illinois early Thursday, you are not alone. The USGS has confirmed there was an earthquake in a part of Illinois that does not commonly have earthquakes.

Around 4:12am on Thursday, September 4, 2025, an earthquake was centered 5km to the west/northwest of Grayville, Illinois confirmed by the USGS.

It was not a big quake at all measured only as a 2.1 magnitude tremor by the USGS, but it was the location that was not typical.

The southern tip of Illinois is often shaken by earthquakes from the New Madrid Fault. The tremor felt Thursday near Grayville, Illinois would have been the result of movement along the Wabash Valley Seismic Zone. While this earthquake fault isn't nearly as infamous as the New Madrid Fault in southern Missouri, the Central United States Earthquake Consortium estimates that this Illinois fault is capable of producing a catastrophic 7.0 magnitude quake someday.

Is this quake a foreshock of a more major quake to follow in Illinois?

There's no way to know that a quake is a foreshock until a larger quake happens, but the recent uptick of Wabash Valley Seismic Zone quakes is something to pay attention to just in case this seismically-active area is about to unleash something more destructive. Being earthquake aware in all parts of Illinois is vital.