Geophysical investigations of icebergs in Antarctica

Abstract

One of the most important technical questions relating to iceberg transport are the causes of disintegration of the iceberg at sea. In order to obtain a better understanding of the factors involved in the response of icebergs to the environment, an automatic data collection platform was placed on a tabular iceberg in the Antarctic in February 1979. This experiment, and an analysis of some of the collected data, form the basis of this thesis. The background for the experiment, details of the instruments, the mounting of the platform and the data collection are outlined. Some relevant research in glaciology, physics and mechanics of ice, oceanography and other related topics is summarised. The collected data (over a period of one year) are divided in three sets:- the dynamical behaviour of the iceberg; thermodynamical data; and mechanical data. Preliminary results of research on the dynamical data have been obtained at other scientific institutes and a summary is given. No analysis of the thermodynamical data has been made. The mechanical data, including surface strain measurements and tilting of the iceberg~ have been analysed at Scott Polar Research Institute by the author. Results from the analysis are given. It's found that the 'instantaneous' surface strain caused by the iceberg's bending in the ocean waves, together with the existence of cracks and crevasses in the iceberg's surface, may be large enough to produce fracture. Other conclusions from the analysis are summarised. Comparisons with other relevant papers on iceberg tilting and bending have been made.