[2] Anchor ice is most commonly observed in fast-flowing rivers during periods of extreme cold, at the mouths of rivers flowing into very cold seawater, in the shallow sub or intertidal during or after storms when the air temperature is below the freezing point of the water, and the subtidal in the Antarctic along ice shelves or near floating glacier tongues, and in shallow lakes.
Anchor ice in rivers can seriously disrupt hydro-electric power plants by significantly reducing flow or stopping turbines completely.
[2] Lakes in the southwestern part of Nunavut, Canada typically freeze down to the bottom when the water level is low.
This downward jet phenomenon was previously described for deltas into the Beaufort Sea, where they were caused by periodic tidal buoyancy of holed ice.
[4] Anchor ice may be formed in the shallow intertidal or subtidal during storms in cold weather, when the uppermost layers of the water column are churned up by strong winds or waves.
Anchor ice may also grow on animate or inanimate objects and lift them from the sea floor.