Frost quakes have been reported in Missouri and some other states this week as a result of the low temperatures and heavy snowfall this winter season. Common signs of this rare natural phenomenon include booming thuds, other strange sounds, and even flashes of light. The Press Herald reports this Wednesday, Feb. 5, 2014, that this frigid occurrence takes place when chilled moisture in the ground abruptly freezes then expands, creating a mini “explosion” that can be heard far and wide.
The frost quakes were experienced most noticeably this Feb. 2014 in St. Louis, where resident Chuck Herron said he witnessed a number of loud thuds near his century-old home, and it sounded not unlike huge snowballs were being thrown nearby. Several calls were even made to 911 after neighbors also heard the booming thuds and light flashes.
However, experts and authorities say that this rare natural phenomenon is nothing too much to worry about. When a certain amount of moisture in the frigid ground suddenly freezes and then expands, the soil or adjacent bedrock can quite literally shatter, not unlike a frozen-over pipe. This occurrence is usually uncommon because both the temperature and winter conditions need to be very specific for these strange noises, cracking sounds, and earthquake-esque rattles to actually happen.
A number of potent frost quakes, which are scientifically known as cryoseism, have been frequently heard this winter due to this 2013 and 2014 season being a “ripe time” for them, adds the report. With frigid temperatures and several sudden heat spells allowing for the needed amount of thawing, these booms and cracks have been encountered more often than in other recent years.
“Such was the case last weekend in Missouri, where temperatures in the 40s on Saturday gave way to single-digit readings by Sunday night ... Furthermore, in Mark Twain’s hometown of Hannibal, Mo., 100 miles north of St. Louis, police and emergency dispatches received several calls within about two hours of the frost quakes. Even Twitter and Facebook feeds were filled with anxiety over these flashes of light and booming thuds.”
Missouri has felt the most of these mini-rumbles, but others have also been confirmed this season in Indiana, Ohio, Wisconsin, and Michigan as well.