Cryoseisms; The Mysterious Boom Sounds

Often times, we here of stories of mysterious explosions and booming sounds that seem to emanate from nowhere and even shake and rattle homes.  These are often associated with various conspiracy type stories of secret government experiments, HAARP weather modification, and even sometimes aliens.  The frequency of reports of these have many folks baffled as to their source.


These mysterious booms and rattles do have a natural source though and they are called, cryoseisms.  A more common term for this might be frost quakes.  A cryoseism occurs  from a sudden deep freezing of the ground.  But more particularly a sudden freezing of the ground where water is present in the ground.  Water expands when it freezes.  When the water in the ground freezes it exerts pressure on the rock to the point where the rock snaps, releasing an audible boom sound and generating a very local shock wave, much like an earthquake.


Because of the very local nature of these events, they rarely are measured by a Richter scale.  Your home could get a good rattling though if you are right near one of them.  The audible boom can go out further from the ground shake.  This leaves people confused too because there seems to be no visible connection to the sound being heard.


Frost quakes have nothing to do with earthquakes, movement of tectonic plates, volcanoes and other factors are unrelated to surface temperature.  Frost quakes usually occur between midnight and dawn, the coldest part of the night.  They can occur over several hours and even several days.  They are most common after a cold rain or thaw event when arctic cold sweeps in afterwards.  They can occur anywhere where the temperatures can drop cold enough to cause a rapid freeze.  They very rarely cause any damage, but they sure can get people excited.