“Frost quakes” felt around Chicago during recent cold wave

Chicago recently experienced a cold wave, which started on January 13 and reached temperatures as low as -23 degrees Celsius, triggering cases of a phenomenon known as “frost quake” or cryoseism.

A cryoseism is an earthquake-like phenomenon, which is caused by sudden earth fracture due to rapid freezing of pore water pressure.

Hence, it only makes sense that for frost quakes to occur, the ground needs to be saturated.

In addition to this, the temperature in the soil needs to rapidly decrease at a rate of roughly 1 degree Celsius per hour.

It has recently been suggested that this is more likely when the environmental temperature suddenly drops below minus twenty degrees.Furthermore, another factor which affects the likelihood of occurrence is whether there is snow present on top of the soil, as it would act like an insulation layer.

Frost quakes usually result in a sudden release of energy due to pressure buildup of the freezing pore water, which may cause booming sounds and seismic waves.

However, cryoseisms produce ground motions of rather low intensity, if any at all, which rarely could be enough to damage structures like roads and foundations.

It is worth noting that cryoseisms are most likely to occur from midnight to dawn, when the lowest temperatures are expected.

Finally, a team of Finnish researchers recently published a paper regarding frost quakes, which is thought to be “the first time we could actually look at these events so precisely”, according to Kari Moisio, a senior researcher at the University of Oulu.