A quarry in Chicago’s west suburban town of McCook is being cited as the source for persons feeling an ‘earthquake’ at approximately 12:35 on Monday afternoon, according to WGN news on Monday. The shaking earth was felt locally and as far north as towns north of the Illinois-Wisconsin border.
McCook’s mayor, Jeffery Tobolski, confirmed that there were two ground-shaking events. The first was a planned quarry blast, and the other occurred 7 seconds afterwards.
The epicenter of the incident seemed to be approximately 2 miles south-southwest of LaGrange, Illinois. This puts the epicenter near a quarry located at 9101 West 47th Street in McCook. The quarry is operated by Hanson Material Service. Hanson said in a written statement that the seismic readings are being reviewed. The firm also asserts that it has no reason to believe there was a connection between the routine blast performed and the seismic event.
The mayor of the town said that Hanson’s equipment somehow indicated that the initial blast was within the parameters that the firm is permitted to blast.
The United States Geological Survey originally called the event a small quake. Later, however, the event was confirmed to have been a single blast event registering at a 3.2 magnitude.
Tobolski, according to the WGN report, said Hanson Materials is a good neighbor – but he is going to be asking more questions about the event.
According to CBS News in Chicago, persons in the area are naturally concerned about damage to the foundations of homes and businesses as they witnessed an ‘earthquake’-like symptom.