A large variety of seismogenic glacial processes arising from internal, ocean calving, or basal processes have been identified and studied.
Occurrences Glacial cryoseisms Ī glacial cryoseism is a non-tectonic seismic event of the glacial cryosphere. The sometime superficial to moderate occurrences may range from a few centimeters to several kilometers long, with either singular or multiple linear fracturing and vertical or lateral displacement possible. Cracks and fissures may also appear as surface areas contract and split apart from the cold. Some reports have indicated the presence of "distant flashing lights" before or during a cryoseism, possibly because of electrical changes when rocks are compressed. Since cryoseisms occur at the ground surface they can cause effects right at the site, enough to jar people awake. Cryoseisms release less energy than most tectonic events. Due to lower- frequency vibrations of cryoseisms, some seismic monitoring stations may not record their occurrence. Furthermore, cryoseisms often exhibit high intensity in a very localized area, in the immediate proximity of the epicenter, as compared to the widespread effects of an earthquake. Cryoseisms can have an intensity of up to VI on the Modified Mercalli Scale. Cryoseisms can, however, be distinguished from earthquakes through meteorological and geological conditions. Initial indications may appear similar to those of an earthquake with tremors, vibrations, ground cracking and related noises, such as thundering or booming sounds. Effects Ĭryoseisms are often mistaken for minor intraplate earthquakes. Speculation has been made between global warming and the frequency of cryoseisms. The requirements for a cryoseism to occur are numerous therefore, accurate predictions are not entirely possible and may constitute a factor in structural design and engineering when constructing in an area historically known for such events. This stress builds up until relieved explosively in the form of a cryoseism. Īs water drains into the ground, it may eventually freeze and expand under colder temperatures, putting stress on its surroundings. For the 2010 novel, see Ice Quake (novel).Ī cryoseism, ice quake or frost quake, is a seismic event caused by a sudden cracking action in frozen soil or rock saturated with water or ice, or by stresses generated at frozen lakes.
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