*The U.S. Geological Survey reported a 4.3-magnitude quake at 3:59:43 a.m. centered about 5.5 miles east of Sycamore and 3.1 miles underground. The epicenter is about 45 miles west of Chicago.
The quake was felt over a wide area, but there were no immediate reports of any damage.
The nature of the fault activity that caused the quake was unclear, said Amy Vaughan, a geophysicist with the geological survey in Golden, Colo. Past quakes that have affected southern Illinois have been in the Wabash Valley or New Madrid seismic zones.
The fault systems in northern Illinois are not as well understood as those in other regions where earthquakes are more common, and more investigation will be needed to determine the cause of this morning’s temblor, Vaughan said.
Reports of tremors came in from Villa Park, Western Springs, Minooka, Batavia, Naperville, Elgin, Oak Lawn, Des Plaines and even Crown Point, Ind. In Chicago, reports came from the Northwest Side and Logan Square. By 4:50 a.m. the USGS had received thousands of reports from as far north as Madison, Wis., and as far south as Bourbonnais. The most distant report came from Hendersonville, Tenn., 648 miles from the epicenter.
“The whole house shook,” said Walter Mockus of St. Charles. “The chimes that hang were all ringing. It was so loud, I thought a plane had gone down.”