KALAMAZOO, Mich. — As the temperatures dropped there were reports of loud cracks and booms across West Michigan on the morning of Feb. 8, 2019.
These booms, or strange cracking noises, were likely the result of something called ice quakes or frost quakes. The official name is cryoseism.
Ice quakes occur when temperatures quickly drop to frigid levels following several days of temperatures above freezing. The temperature drop is not the only precursor to an ice quake, though.
The soil also needs to be fairly saturated with water, which was definitely the case after the large amount of snow melt.
The water in the soil mixed with the rapidly dropping temperatures turns the water to ice, which expands in the process. The expansion exerts pressure on the frozen soil and rocks around it, which cause a loud crack or boom sound to reverberate around a fairly localized area.
Ice quakes are generally harmless, but in rare instances the have caused damage to structural foundations or caused light shaking of the earth similar to a low-end earthquake. They are most common in the upper Midwest and northeast, locations susceptible to some of the most extreme temperature swings during the winter.