Abstract
A simple analysis is presented to examine the forces necessary to create a large shear wall of ice which was observed in the Beaufort Sea. This shear wall was approximately 130 m long and 23 m high (from the seabed). Two types of analysis are presented. First, a distinct feature of a 0.8 m thick ice floe which had been pushed up the 8 m high (above the ice level) rubble pile was analyzed by considering a number of analytical models for ice ride-up. The analysis showed that the line loads were estimated to be on the order of 65 to 150 kN/m, and 90 to 208 kN/m for friction values of 0.3 and 0.5 respectively. A second analysis of the creation of the shear wall by a large-scale shearing event suggested the global force would have been on the order of 42 to 90 MN. These values are in agreement with measurements of global ice loads on offshore caisson structures. The analysis was extended to estimate the pack ice driving force for this event. Although a number of gross assumptions were made, the calculated values are in good agreement with other previous estimates of the pack ice driving force in the Beaufort Sea. Overall this study has indicated that observations of these large ice features and subsequent analysis can be a very useful method for gaining additional insight on pack ice driving forces.
