Prediction of an Iceberg Drift Trajectory During a Storm

A numerical model is presented for predicting iceberg drift trajectories from known or derived information regarding iceberg characteristics and the environmental forces affecting the motion of an iceberg. The validity of such a model is studied by comparing predicted and observed trajectories of icebergs near Saglek, Labrador, during a storm on 21–22 August. 1972. At this time, iceberg positions (determined by radar), winds, and currents were monitored as part of an oceanographic study, conducted by the Faculty of Engineering and Applied Science, Memorial University of Newfoundland. The comparison between observed and predicted iceberg drift trajectories is good when the characteristics of the iceberg are assumed to be those of a mediumsized non-tabular iceberg. In order to appreciate the effect of wind and current forces on the drift of the iceberg, several trajectories arc plotted in which various environmental forces are excluded. From this study, it is evident that a good prediction of an iceberg drift trajectory is only possible if rather detailed information is available on the current and wind field.