A state inspector will review the blasting records of a west suburban quarry near where a disturbance measuring 2.7 on the Richter scale shook the area Tuesday afternoon.
Chris McCloud, spokesman for the Illinois Dept. of Natural Resources, which regulates mine blasting, said officials of Hanson Materials Co. in McCook said their operations may not have caused the seismic event about 1 p.m. Tuesday.
’They do not believe, after reviewing their own blasting records, that type of effect would have been felt based on the explosives they used,’ McCloud told Pioneer Press.
It is up to the U.S. Geological Survey to determine whether the event was an earthquake, he said. ’The Department of Natural Resources does not have the staff or experts to decide whether it was an earthquake. That hasn’t been determined.’
Don Blakeman, geophysicist with the USGS National Earthquake Center, said Wednesday seismic activity records are open to interpretation.
’We can’t tell for sure by looking at the waves what event it was, but the more information we’re getting, it was probably a quarry blast, Blakeman said. ’Whatever it was, it was located very close to this quarry.’
Residents of La Grange, not far from the quarry at 47th Street and East Avenue, reported glass shattering, and pictures and shelves falling off the wall.
Blakeman said it’s unusual for mining blasts to have a major impact of 2.7 on the Richter scale in the Chicago area.
Andrianna Peterson, La Grange village spokeswoman, said the impact was felt several miles away at the Village Hall. ’We’ve had people working here 25 years who’ve never felt anything like this,’ she said.
The village received one or two calls Monday inquiring about quarry blasting and several dozen the following day.
’I’m assuming the hot line had dozens of calls as well,’ she said referring to the Lyons Township Quarry Complaint Line (866-WE-HEAR-U).
The village has joined with a number of township communities near the quarry to meet quarterly with quarry officials on issues of concern, including blasting, truck traffic and debris, Peterson said.