Did you hear it? Did you hear a loud bang that you did not know where it was coming from? Turns out, it might be a frost quake.

What You Need To Know

  • St. Louis residents reported hearing loud booms or cracks

  • Frost quakes occur in specific weather conditions, including a low snowpack and rapid temperature drop

  • The "quakes" are so small they don't show up on seismographs

Earlier this week, residents in the St. Louis area reported hearing booms, but there were no indications of an earthquake. What caused the sound?

What is a frost quake?

National Weather Service Kansas City Meteorologist Randall Collier explains a frost quake is the reason for the noise. “A frost quake is a seismic occurrence resulting from underground water freezing and expanding, placing additional stress on its surroundings (i.e. ice, frozen soil, rocks).”

The sound that is heard is due to the relief of the stress. “The stress is relieved, eventually yielding an explosive cracking or booming sound known as an ice quake. Other names include an ice quake or a cryoseism.”

It’s a rare occurrence because specific weather conditions are needed, including a minor snowpack (less than 6 inches) and a rapid temperature drop.  

Our team of meteorologists dives deep into the science of weather and breaks down timely weather data and information. To view more weather and climate stories, check out our weather blogs section.