Observations on the Physical Properties of Sea-Ice at Hopedale, Labrador

Preliminary results are reported of field studies 1955-56 by the U.S. Air Force Cambridge Research Center, the Hydrographic Office and SIPRE on the general physical properties of sea ice; methods of measurement are described. Characteristics of sea water during the freezing period are outlined: formation, structure, and salinity of the initial ice cover, formation and characteristics of infiltrated snow-ice, growth of the ice and influencing factors, density of the ice at various periods, and crack formation are discussed. Data on the salinity of sea ice formed during during wave action and that of sheet-ice, hourly averages of air and ice temperatures at various levels, snow and slush density and thickness, observed slush levels and theoretical water levels are shown. Salinity of ice before and after the slush layer froze, and that of deteriorating ice , salinity of ice vs. ice thickness, thickness of ice versus degree-days, the density of the ice, and measured ice densities vs. theoretical density of air-free sea ice at -15 C are figured and discussed. The orientation of sea ice c-axes and of infiltrated snow-ice c-axes are diagrammed.--From SIPRE