Modelling of iceberg drift

El-Tahan, Mona Salah Shahwan (1980) Modelling of iceberg drift. Masters thesis, Memorial University of Newfoundland.

[English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (26MB) [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

Abstract

The need for a numerical model to predict iceberg drift arises primarily due to the hazards that icebergs present to the drilling vessels and platform in the offshore areas near Newfoundland and Labrador. -- A dynamic model has been developed and used to study the behaviour of icebergs under different wind and current conditions. -- The forces considered are due to wind, current, Coriolis effects, pressure gradients (ocean surface slope) and the acceleration of water body surrounding the iceberg. Two different techniques were used to solve the coupled non-linear differential equations of motions: i) analog computer simulation and ii) digital computer using 4th-order Runga-Kutta method. -- The validity of this model is verified by comparing the predicted and observed iceberg trajectory during a storm on August 21-22, 1972 when an oceanographic study, conducted by the Faculty of Engineering and Applied Science of Memorial University of Newfoundland, was in progress near Saglek, Labrador to monitor iceberg positions with the help of radar. The detailed wind and current data measured in-situ near the icebergs, provided a unique opportunity to verify the model and to study the effect of each of the environmental forces. Several trajectories are obtained after excluding each one of the environmental forces used in the model in order to appreciate its effect on the drift of icebergs. -- In an attempt to obtain better understanding of the observed looping and spiral motions of icebergs, several trajectories are plotted for iceberg drifting under the environmental conditions thought to be responsible for this strange behaviour. Changes in the ocean surface due to low pressure systems were found, using finite element analysis to have no effect on the currents, and hence on the iceberg trajectory. -- This study has demonstrated the importance of each of the environmental forces included in the model. A good prediction of an iceberg drift trajectory is only possible if all the environmental forces are accounted for and detailed wind and current data in the immediate vicinity of the iceberg as well as good estimates of iceberg parameters are available as input to the model.

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