Determining the influence of waves on the physical behaviour of the sea ice with mechanically generated waves

The interaction of the ocean wave field with the sea ice was investigated by creating a wave generating machine to generate waves which have clearly defined parameters such as amplitude and frequency. A block of ice was cut from the ice sheet and attached to a computer controlled hydraulic activator suspended from a steel frame. The movement of the block in and out of the water generates a cyclical force on the ice through the frame which generates the waves that then propagate out in a cylindrical fashion. The waves are detected by tilt meters placed at distances up to 5km from the source. By relating the phase and amplitude of the detected waves with the phase and amplitude of the source the influence of waves on the physical behaviour of the sea ice was determined. This was tested over two seasons and the source was positioned in an area of known cracks and an array of tilt meters were radiating out from the source and spanning the crack for measurements. The relative locations on the source and detectors as well as the cracks were mapped by GPS. The results should enable the construction of a model of wave propagation in the presence of imperfections and consequently further enhance the understanding of the break up processes occurring in the marginal ice zone.