Oceanography

Properties of sea ice

The physical properties of sea ice depend upon the a) salinity of sea water from which it forms,b) temperature,c) air-content or porosity, d)pressure,e)speed of ice formation,and f)age and history of the ice. As soon as the temperature of the sea surface reaches the freezing point, pure ice begins to form. At this stage, sea water is trapped among the ice crystals. On further cooling, the various salts present in the sea water crystallize gradually depending upon the temperature. For example, sodium sulphate (Na₂SO₄ 10 H₂O) crystallizes at -36.0^oC and calcium chloride (CaCl₂) crystallizes at -55.0^oC (Ringer, 1928).