Cryoseism

A cryoseism, also known as an ice quake or frost quake, is a type of shaking event that happens when frozen soil or rock suddenly cracks. This usually occurs in places where the ground has a lot of water or ice.

When water gets into the ground and freezes in very cold weather, it gets bigger. This can push and strain the soil and rock around it. After a while, this pressure can cause a sudden break, leading to a cryoseism.

These events need special conditions to happen, so they are hard to predict. This makes them important to think about when building in places where they have happened before.

There is some talk about how global warming might change how often cryoseisms occur, but it is still hard to guess when they will happen. Learning about cryoseisms helps scientists and builders create safer structures in cold areas.

Effects

Cryoseisms are sometimes confused with small intraplate earthquakes. They can make the ground shake, crack, and produce loud noises. But cryoseisms are different from earthquakes because of their meteorological and geological conditions. They usually affect only a small area near the epicenter. Some seismic stations might not notice them because their vibrations are lower-frequency.

Some people say they see flashing lights far away before or during a cryoseism. This might happen because of electrical changes when rocks are squeezed together. Cracks and fissures can form as the ground contracts and splits apart from the cold. These cracks can be a few centimeters to several kilometers long and may shift up or sideways, called displacement.

Occurrences

Glacial cryoseisms

A glacial cryoseism or glacial ice quake is a non-tectonic seismic event in the glacial cryosphere. Big pieces of ice breaking off in Greenland and Antarctica can create seismic events. Very large icebergs can also make seismic signals when they crash or move. When water builds up under a glacier, it can let the glacier shift suddenly, creating seismic waves. These events can be very short or last for many minutes.

Location

United States

Cryoseisms have been reported in the Midwestern, Northern and Northeastern United States. On January 26, 2026, after a big winter storm in Middle Tennessee, frost quakes were felt by many people there and in part of Southern Kentucky.

Canada

Cryoseisms happen in Canada, especially near the Great Lakes and St. Lawrence area. They have been noted in Ontario, Quebec, Alberta and the Maritime Provinces.

Other places

Glacier-related cryoseism events have also been observed in Alaska, Greenland, Iceland, Finland, Ross Island, and the Antarctic Prince Charles Mountains.

Precursors

For a frost quake to happen, several conditions must be met: the area needs to be able to get very cold, the ground must be wet from melting snow or rain before a cold snap, there usually needs to be only a little snow on the ground, and the temperature must drop quickly to near or below −18 °C (0 °F) over 16 to 48 hours. Cryoseisms often happen when temperatures fall rapidly from above freezing to below freezing, usually between midnight and early morning. Because glaciers are always cold, glacier-related cryoseisms can also happen in summer. These events usually occur 3 to 4 hours after a big temperature change. They are more common in areas with permeable ground like sand or gravel.