Frazil ice

[1][2][3][4][5] Frazil ice forms during the winter in open-water reaches of rivers as well as in lakes and reservoirs, where and when the water is in a turbulent state, which is, in turn, induced by the action of waves and currents.

[3][5][6] The vertical mixing associated with that turbulence provides enough energy to overcome the crystals' buoyancy, thus keeping them from floating at the surface.

Frazil ice also forms in oceans, where windy conditions, wave regimes and cold air also favor the establishment of a supercooled layer.

Turbulence, caused by strong winds or flow from a river, will mix the supercooled water throughout its entire depth.

Frazil ice has also been demonstrated to form beneath temperate (or "warm-based") glaciers as water flows quickly downhill and supercools due to a rapid loss of pressure.

This final method is often not preferred because of high labour costs, cold, wet and late night working conditions.

Back flushing is another technology that uses the idea of cancelling out the differential pressure caused by the frazil ice accumulation.

Installing hollow tubes in the structures through which steam or warm water is pumped also works, but this method has been judged as uneconomical to operate.

Alternatively, the waste water may instead be recirculated to directly warm surfaces prone to frazil ice accumulation.

[13] Although still in the experimental stages, blasting with dynamite is one form of vibrational control that will break loose any frazil ice accumulation.

[citation needed] Damage could be reduced by protecting designated flood regions with mechanical structures.