Very low‐frequency reverberation in the Arctic Ocean

During March and April of 1978 a camp was established on the Arctic ice over the Canada Abyssal Plain, including a horizontal receiving array, a multichannel data handling and storage system, and a digitally operated data analysis system. With the use of TNT charges of up to 880 pounds, acoustic reverberation in the Arctic Ocean was measured. Emphasis in data analysis was placed on the frequency range centered on 10 Hz. Reverberant (scattering) returns were obtained for elapsed times up to and greater than about 30 min (ranges greater than about 1300 km). The receiving array was about six wavelengths long, and helped to identify various topographic features in the Arctic Ocean. Measurement results and theoretical models will be presented and discussed. [These efforts were undertaken jointly with The Woods Hole Oceanographic Institution, the Lamont‐Doherty Geological Observatory, and the Bedford Institute of Oceanography. Work supported by the Arctic Program Office of ONR.]