Residents across the Chicago area felt the tremors of a 2.9 magnitude earthquake that struck beneath Lake Michigan on Wednesday afternoon.
Why it matters: This earthquake, which occurred in an area not known for seismic activity, highlights the rarity of such events in the Midwest.
The quake began at approximately 2:38 p.m. CDT, according to the U.S. Geological Survey (USGS).
It was centered about 20 kilometers (12.5 miles) off the coast of Kenilworth, Illinois, and about 3.1 miles deep.
By 4:30 p.m., over 100 residents had reported feeling the tremors, with most reports coming from the North Shore suburbs.
Driving the news: The earthquake's epicenter was situated approximately 13.8 miles northeast of Evanston and was felt across a wide area.
Reports of the quake came from multiple suburbs including Highland Park, Glencoe, Wilmette, and as far south as Chicago's South Side.
Interestingly, Loves Park, located over 77 miles from the epicenter, also reported sensation of the tremors.
In total, reports were received from communities more than 75 miles away, indicating the quake's broad reach.
State of play: The USGS classified the earthquake as minor, noting that it is typically felt by some but rarely causes damage.
Seismologists indicated that earthquakes in the central and eastern United States are less frequent than in the western regions, but they can be felt over larger areas.
No injuries or structural damage have been reported following the earthquake.
Only one other recorded earthquake beneath Lake Michigan, also measuring 2.9 magnitude, occurred in August 2024.
The big picture: Earthquakes in the Chicago area are unusual, making this event particularly notable.
Dr. Suzan Van Der Lee, an earth scientist at Northwestern University, explained that the region is not located on active fault lines, yet it experiences minor earthquakes due to ancient geological formations.
The last major earthquake in Illinois was a 5.2 magnitude quake in 2008 near Mt. Carmel, which is significantly stronger than Wednesday’s tremor.
The geological activity in this region is typically linked to movements along old faults buried deep beneath the surface.
What they're saying: Residents shared mixed reactions to the tremors, with some feeling the quake and others unaware it had occurred.
Stephen Lewis, a resident of Evanston, initially thought the rumbling was a truck passing by until he saw news reports confirming the earthquake.
His husband, E. Patrick Johnson, who was working in the basement, felt nothing at all.
Some students at Northwestern University experienced the quake differently; some felt it, others did not, leading to conversations about the event.
By the numbers: The magnitude of 2.9 classifies this earthquake as weak.
Reports of shaking were submitted to the USGS from over 100 individuals by late afternoon.
The earthquake occurred at a depth of approximately 3.1 miles beneath Lake Michigan.
Seismic activity like this is rare, with only two recorded instances of a 2.9 magnitude quake in Lake Michigan in the last 100 years.
What's next: Residents are encouraged to report their experiences to the USGS to help scientists understand the impact of such quakes.
Officials are monitoring any aftershocks, though they are expected to be mild and unlikely to be felt.
The USGS will continue to analyze data from this earthquake to assess its implications for the region.
As awareness of seismic activity grows, educational efforts may increase to prepare residents for future occurrences.