Acoustical determination of the ice growth in the Arctic

Abstract

A crosshole tomography experiment was conducted in the Arctic between April 1992 and March 1993 to determine the time evolution of the acoustic/elastic properties of sea ice. Data were taken every third day for 9 months using an array of vertical and horizontal transducers located in the ice and water column below the ice. A method to monitor the growth of the underside of the ice consisted of comparing the arrival times of both the direct path and reflected path from transmitters in the water column to the receivers in the water column. The differences in arrival times over the 9 months indicates as much as 1-m growth of ice. In addition to the ice growth estimates, the reflection coefficient was determined as a function of time and angle. Acoustic characteristics of the ice in the skeletal layer at the ice/water interface was also estimated.