Indianapolis, Indiana – A rare Midwest earthquake early Tuesday, Jan. 20, is now raising concern across Indiana and Ohio as a surge of Arctic air sends temperatures sharply lower, creating conditions that could lead to frost quakes across the region.
According to the U.S. Geological Survey, a 3.5 magnitude earthquake struck central Illinois shortly before 2 a.m. Tuesday, Jan. 20, centered about 35 miles south of Springfield. The shallow quake was felt across a wide portion of Illinois, with thousands reporting shaking, rumbling, and rattling windows before sunrise. While no damage was reported, seismic events of this size are uncommon in the Midwest, making the timing notable as extreme cold quickly followed.
As the deep freeze spreads east across Indiana and Ohio, geologists say rapid temperature drops can trigger frost quakes, also known as cryoseisms. These occur when moisture in the ground freezes suddenly, causing soil and rock to contract and crack. The resulting boom or vibration can feel similar to a small earthquake and often happens overnight or before dawn.
Parts of Indiana and Ohio, including Indianapolis, Fort Wayne, Muncie, Columbus, Dayton, Toledo, and areas along the I-70 and I-75 corridors, may be more susceptible as temperatures plunge following recent rain or snow. Frost quakes are shallow and localized but can crack pavement, foundations, and underground utilities, especially in areas with saturated or frozen ground.
Emergency officials emphasize that frost quakes are not tied to fault lines and do not signal larger earthquakes. Residents are encouraged to remain alert during the coldest hours, inspect property if shaking or loud booms are noticed, and report ground movement to local officials or the USGS. With dangerous cold expected to persist through midweek, additional advisories or alerts may follow.
