Early Monday morning, residents of DeKalb County were jostled awake by a 3.4 magnitude earthquake centered near Somonauk, Illinois, as reported by the Chicago Sun-Times. The tremor, striking just before 3 a.m. approximately one mile northwest of the town, was also confirmed by the United States Geological Survey (USGS).
Although the quake caused light shaking, no damage has been reported. The USGS noted the earthquake had a depth of 9.8 kilometers and interestingly, just last November DeKalb County experienced a 3.6-magnitude quake, which was the strongest in Northern Illinois for years, these incidents highlight the presence of active fault systems in the area, including the 'Sandwich Fault Zone' and Peru Monocline. According to information by the DeKalb County Sheriff's Office posted on Facebook at 3:14 a.m., "Information for those who were woken up a short time ago to your house shaking, there was just a 3.4 magnitude earthquake northwest of Somonauk."
While the area is not known for severe seismic activity, it does lie in proximity to the Wabash Valley Seismic Zone and the New Madrid Seismic Zone, zones that put Illinois at significant risk for earthquakes, this risk is something the Illinois Emergency Management Agency and Office of Homeland Security have previously warned about, stating that there's a 25% to 40% chance of experiencing a magnitude 6.0 or greater earthquake within the region during any 50-year time span, as revealed by NBC Chicago.
Historical data reflect that Illinois, on average, experiences five earthquakes annually, though most go unfelt by the populace, the strongest earthquake to ever hit the state was a 5.3-magnitude quake near Norris City in November 1968, and in terms of the northern region, a 5.1-magnitude event occurred near Lockport in May 1909, Stamp these phenomena with a uniqueness given that only eight earthquakes have been documented in the Chicago area, a reality that keeps the city and its denizens ever cautious of the ground's surprising ability to move beneath their feet.
