A cryoseism (pronounced krī′ ō sī′ zəm), also known as an ice quake or a frost quake, is a non-tectonic seismic event caused by the sudden freezing and expansion of water-saturated soil or rock, causing a crack and resulting in a loud sound. This happens in response to a sudden drop in temperature. The stress created by the freezing water builds up and then is explosively released. Cryoseisms are often mistaken for weak earthquakes. In North America they have been observed in Canada and the U.S., particularly along the Great Lakes/St. Lawrence corridor where rapid changes in winter temperatures occur. Glacier-related cryoseisms occur in Alaska, Greenland, Iceland, and some locations in Antarctica.

The recent near-record low temperatures experienced in the Chicago area (midwest USA) — with temperatures dipping down to -30°C (-23°F) — set up ideal conditions for ice quakes. On 30 January 2019, some Chicago residents reported hearing bangs, knocks, and booms that appear to have been cryoseisms. (News coverage: Time, Science Alert.) Ice quakes can be substantial, with one occurring on Lake Mendota in Madison, Wisconsin (USA) measuring 3.8 on the Richter scale on 15 January 1948.