(Fremont County, WY) – Fremont County residents may have been startled by loud booms that shook and rattled homes this weekend, after having experienced what are known as “frost quakes.”
With confirmed reports in Lander and Kinnear, questions were posted to various social media groups on January 29 and 30 wondering if others had heard the “loud booms,” with many commenting that it sounded as though their “roofs were going to cave in.”
Speculation as to the cause of the loud noises ranged from ice dams on roofs shifting, wildlife colliding with the sides of houses, to even the potential eruption of the Yellowstone Caldera Supervolcano.
County 10 reached out to our meteorologist Dave Lipson, who filled us in on the phenomenon.
Frost quakes, or cryoseism, occur when water saturates the ground, usually from a recent snowfall, and the temperature drops quickly to sub-zero.
The freezing groundwater is entrapped below a layer of ice crust at the soil’s surface, and then begins to expand, according to Lipson.
When the pressure builds up as the frozen water expands, it pushes and stresses nearby rock, and when the pressure becomes too much, the ground breaks under the stress, causing the loud booms.
Frost quakes typically occur at night when severe temperature drops are most likely to happen, and while not deadly like earthquakes, are known to shake buildings and rattle windows.
While they are more common to hear out on a frozen lake while ice fishing or in more rural areas, Lipson added that the frost quakes were most likely caused by the Arctic air trapped in the basin areas following the weather system that moved through the county this weekend.