High Quality Content by WIKIPEDIA articles! The 2008 Illinois earthquake was one of the largest earthquakes ever recorded in the state of Illinois, measuring a magnitude of 5.4. It occurred at 4:37:00am CDT (9:37:00 UTC) on April 18 within the Wabash Valley Seismic Zone at a depth of 11.6 km. It was centered near West Salem, Illinois and Mount Carmel, Illinois (the affected area is west of Terre Haute, Indiana and Vincennes, Indiana; east of St. Louis, Missouri; and northwest of Evansville, Indiana), specifically 38.450°N, 87.890°W, and felt as far as 450 miles (724 km) away.Tremors were felt as far west as Nebraska and Kansas City, as far south as Atlanta, as far east as Kitchener, Ontario and West Virginia, and as far north as the Upper Peninsula of Michigan. The earthquake was felt so far away, compared to earthquakes in other regions, because the old, rigid bedrock beneath much of the Midwest allows the tremor to propagate further.