Many Madison residents who awoke to shaking early Friday were surprised to learn that they had experienced a rare Midwestern earthquake.
The 5.2 magnitude earthquake occurred at 4:40 a.m. and was centered six miles away from the southern Illinois town of West Salem, according to the UW-Madison geology department. The quake lasted approximately one minute and was felt by people in several areas of the Midwest, including Madison.
A UW-Madison geology department seismometer located in Weeks Hall recorded the tremors. Around 10:15 a.m., an aftershock from the earthquake rattled Madison for a second time, according to UW-Madison geologists.
On Jan. 31, an ice quake"" on Lake Mendota created a tremor-like sensation that shook several lakeshore areas of campus. The ice quake occurred because of a sudden drop in temperature that caused the ice to shift, leaving a visible rift on the shoreline of Lake Mendota.
