Some residents in the Upper Midwest were surprised to be shaken by an earthquake last night.
The United States Geological Survey reported that the earthquake, which had an estimated magnitude of 4.3, was centered near Virgil, about 50 miles northwest of Chicago, at a depth of about three miles. There were no immediate reports of aftershocks... Amy Vaughan, a geophysicist with the agency, said that the tremor was only the second notable earthquake in more than 30 years to rattle the area. Even though the quake was relatively small, it was felt by residents as far away as southern Wisconsin...
One of the best sources for information on earthquakes is the U. S. Geological Survey; the map above shows that earthquakes are common along the Pacific coast, but in just the past week they have also been recorded near the New Madrid fault and in New Jersey, Tennessee, Texas, and the Rockies. A comparable map of world earthquakes is available at the same link.
News link. USGS link.