200th Anniversary of the First Recorded Chicago Earthquake
August 20, 1804
Two hundred years ago, an earthquake shook the southern Lake Michigan area and was recorded by the small number of inhabitants who lived in what is now Chicago. Work on Fort Dearborn, constructed among four cabins erected by French fur trappers near the Chicago River, had just started in late 1803. Reports from that era indicate that the earthquake was quite strong and was also felt in Fort Wayne, Indiana, 200 miles away. Scientists estimate that the earthquake had a magnitude of roughly 4.5, slightly stronger than the June 28, 2004, earthquake that occurred about 60 miles west of Chicago in La Salle County.
Other Chicago Area Quakes
The 1804 temblor isn't the only earthquake to shake the Chicago area. On May 26, 1909, one of the largest earthquakes in Illinois, with an estimated magnitude of 5.1, occurred in northern Illinois. The exact location isn't known, but the greatest shaking occurred in and near Aurora where many chimneys fell, a stove overturned, gas lines ruptured, and a fire started. Elsewhere, houses were jostled out of plumb in Beloit, Wisconsin, and brick walls were cracked as far away as Bloomington, Illinois.
These historical events are reminders that earthquakes have occurred throughout Illinois and can happen again with the possibility of even larger magnitudes.
Updated 05/18/11 SLD