Indianapolis, Indiana – A rare Midwest earthquake early Tuesday is now raising awareness across Indiana as a surge of Arctic air sends temperatures sharply lower, creating conditions that can lead to frost quakes during the coldest overnight hours.
According to the U.S. Geological Survey, a 3.5 magnitude earthquake struck central Illinois shortly before 2 a.m. Tuesday, centered roughly 35 miles south of Springfield. The shallow quake was widely felt across Illinois, with residents reporting brief shaking, rumbling sounds, and rattling windows. While no damage was reported, earthquakes of this size are uncommon in the central Midwest.
As the deep freeze spreads into Indiana, geologists say rapid temperature drops can trigger frost quakes, also known as cryoseisms. These occur when moisture in the ground freezes quickly, causing soil and rock to contract and crack suddenly. The resulting shock can sound like an explosion or feel similar to a small earthquake, often occurring overnight or before sunrise.
Areas across central and northern Indiana, including Indianapolis, Lafayette, Kokomo, Fort Wayne, and parts of northwest Indiana, may be more vulnerable as temperatures fall into extreme cold following recent precipitation. Frost quakes are shallow and localized but can crack pavement, foundations, and underground utilities.
State emergency officials say frost quakes are typically not dangerous, but residents should remain alert, avoid unnecessary nighttime travel, and inspect property for new cracks if shaking is felt. Any reports of ground movement can be shared with local officials or the USGS as the cold persists through midweek, with additional advisories possible if conditions worsen.
