Below is a message we received from the Wisconsin Emergency Management folks in Madison.
During the afternoon hours of Thursday, March 22, 2012, the U.S. Geological Survey (USGS) reported that a 1.5 magnitude earthquake struck early Tuesday morning (March 20th) in Clintonville, WI. The earthquake struck shortly after midnight early that Tuesday morning.
Officials with the USGS say loud booming noises have been known to accompany earthquakes and it is possible the strange sounds residents have been reporting at night might be related to the earthquake.
Wisconsin Emergency Management has worked with Waupaca County Emergency Management Director Andrew Carlin and other local officials in regards to the strange booming noises that have occurred this week.
According to Tom Evans, Assistant Director with the Wisconsin Geological and Natural History Survey (WGNHS), Wisconsin has experienced about a dozen minor events attributed to low seismic activities in the last 100 years. He says Wisconsin sits on a relatively stable part of the continent.
Details about the earthquake are available at the USGS website, http://earthquake.usgs.gov, and http://earthquake.usgs.gov/earthquakes/recenteqsus/Quakes/usc0008n7t.php#details.
Kapela, WFO Milwaukee