Which ice forms during the initial freezing action of water and is often associated with rapid freezing?

• A. Clear ice
• B. Frazil ice
• C. Rotten ice
• D. Drift ice

Answer: (B)

Frazil ice forms during rapid freezing of moving, turbulent water. When water is chilled quickly and kept in motion, many tiny ice crystals develop simultaneously rather than a single solid sheet. These crystals are usually needle- or plate-like and float in the water, giving a milky, slushy appearance. This stage is common in rivers, outfalls, or other fast-flowing cold-water areas where turbulence prevents the crystals from coalescing into a uniform mass. As freezing continues, frazil crystals can accumulate and later organize into larger ice forms, but the initial action is defined by these rapid, suspended crystals.

Clear ice, by contrast, comes from slow, uniform freezing in still water, producing a transparent solid. Rotten ice refers to ice that has decayed or weakened due to warm conditions or sediment interaction. Drift ice describes large floating chunks carried by winds and currents.