The magnitude of a small pre-dawn earthquake that hit northern Illinois on Feb. 10. The Illinois State Geological Survey (ISGS) said the earthquake was felt in eight states and was reported by more than 10,000 people. The epicenter was one mile east of Pingree Grove in Kane County and about 7 miles below the ground surface. The U.S. Geological Survey initially reported the magnitude as 4.3 but later downgraded it.
While rare, there have been previous earthquakes recorded in Northern Illinois, including: DuPage County, 1985, magnitude 3.0; Kane County, 1944, magnitude 2.7 and 1947, magnitude 3.1; Kendall County, 1912, magnitude 4.7; and Will County, 1909, magnitude 5.1, which caused damage and fires. The last earthquake felt in Chicago was on June 28, 2004, in LaSalle County with a magnitude of 4.2, the ISGS said.