Ice spike

An ice spike is an ice formation, often in the shape of an inverted icicle, that projects upwards from the surface of a body of frozen water. Ice spikes created by natural processes on the surface of small bodies of frozen water have been reported for many decades, although their occurrence is quite rare. A mechanism for their formation, now known as the Bally–Dorsey model, was proposed in the early 20th century but this was not tested in the laboratory for many years. In recent years a number of photographs of natural ice spikes have appeared on the Internet as well as methods of producing them artificially by freezing distilled water in domestic refrigerators or freezers. This has allowed a small number of scientists to test the hypothesis in a laboratory setting and, although the experiments appear to confirm the validity of the Bally–Dorsey model, they have raised further questions about how natural ice spikes form, and more work remains to be done before the phenomenon is fully understood. Natural ice spikes can grow into shapes other than a classic spike shape, and have been variously reported as ice candles, ice towers or ice vases as there is no standard nomenclature for these other forms. One particularly unusual form takes the shape of an inverted pyramid.

Although natural ice spikes are usually measured in inches, a report that appeared in the Harbor Creek Historical Society Newsletter by Canadian Gene Heuser, who hiked across frozen Lake Erie in 1963, spoke of "small pinholes in the ice through which the water below was periodically forced under pressure to spout up into the air and freeze" producing five feet high "frozen spurts that looked to him like telephone poles standing straight up all over the lake".

Ice spikes have been reported as a rare natural phenomenon for decades. A model of the mechanism of formation was put forth independently by O. Bally and H.E. Dorsey in the early 20th century and this is still the most widely accepted explanation of the phenomenon today. Spikes tend to form in containers such as bird baths and pet drinking bowls, where the water freezes quickly, rather than in large bodies of water such as lakes and ponds. A number of web pages displaying photographs of unusual ice formations and discussing the phenomenon have been published, and a number of cases of ice spikes being formed on ice cubes in domestic refrigerators have been reported. The ability to grow ice spikes in a controlled environment has prompted a small number of investigations by the researchers in the Physics Department of the California Institute of Technology under the direction of Kenneth G. Libbrecht into the conditions needed for the spikes to form.

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