Laboratory experiments on oil spreading in broken ice

In December 2000, laboratory tests were conducted at Hamburgische Schiffbau Versuchsanstalt (HSVA) to investigate the process of oil spreading in cold waters with broken ice. A total of 20 tests was carried out. In each of them, oil was poured on the water surface. Oil spreading and floe motion were closely monitored by video cameras and the pictures were analysed to find how different parameters influence the oil spreading. The following parameters were varied: floe motion, ice concentration, slush concentration and oil type. It was found that spreading rates decreased for increasing ice concentrations, but the effect was small for ice concentrations below 20–30%. The presence of slush strongly reduced the spreading, so that the effect from varying the ice concentrations was reduced. Increased motion in the ice cover resulted in increased spreading rates, and this effect was especially pronounced in the presence of slush.