Things that go bump in the night are generally explained by falling tree branches or playful cats, but sometimes those thumps give you quite a start and leave you with an uneasy feeling when you can’t locate the source. If the night is as cold as those we’ve recently experienced, you can blame the sound on frost quakes, and rest easy.
Cryoseisms, better known as frost quakes or ice quakes, cause loud booms and often rattle your nerves as badly as they rattle your dishware.
Michael Hansen of the Ohio Seismic Network said these are not uncommon occurrences in Ohio, but do require special conditions. A thaw or rain to saturate the soil, followed by a quick freeze which causes the water to expand rapidly results in the boom heard by startled residents.
Cryoseisms generally happen at night, when the temperatures are the coldest. Fissures in the soil may be seen afterward, but are often too small to notice or are hidden by snow.
Hansen noted that the unexplained nighttime noises in Richland County could well be the result of cryoseisms. “It’s a logical conclusion, even though there’s no concrete evidence,” noted Hansen.
“These never show up on seismic instruments. There’s not enough energy produced,” added Hansen.
Cryoseisms are often a localized occurrence, sometimes only felt at a single location. However, during the recent cold snap, Richland Source Editor Rhonda Bletner and I, miles apart, had our evenings shattered by loud noises we now assume were frost quakes.
“I thought a tree branch had fallen on the house,” said Bletner. “I went out and walked all around the house, but didn’t see anything.” She added that she’d forgotten about frost quakes, and had worried the noise came from her furnace.
Hansen noted that though a few papers have been published on cryoseisms, not a lot is really known about them. “It’s hard to study this type of phenomenon,” said Hansen.
According to Hansen, in February 2011 there were reports of cryoseisms from all across the state, including west Ohio and into Indiana, though not all at the same time, as would be expected with an earthquake.
“We’re always glad to check it out if people think it’s an earthquake,” said Hansen. Earthquakes may be reported at the website or by calling the 24 hour earthquake reporting hotline at: 1-855-QuakeOH.
Along with light pillars and snow rollers, frost quakes are just another of Mother Nature’s winter surprises.
