Multi-modal and short-range transmission loss in ice-covered, near-shore Arctic waters

Prior to the 1970s, extensive research has been done regarding the sound propagation in thick (kilometers) ice sheets in Arctic and Antarctic environments. Due to changing climate conditions in these environments, new experimentation is warranted to determine sound propagation characteristics in, through, and under thin-ice sheets (meters). In April 2016, several experiments were conducted approximately 1 mile off the coast of Barrow, Alaska on shore-fast, first year ice, approximately 1.5 m thick. To determine the propagation characteristics of various sound sources, Frequency Response Functions (FRFs) were measured between a source location and several receiver locations at various distances from 50 m to 1 km. The primary sources used for this experiment were, an underwater speaker with various tonal outputs, an instrumented impact-hammer on the ice, and a propane cannon that produced an acoustic blast wave in air. In addition, several anthropogenic sources, namely, a snowmobile, generator, and ice auger, were characterized. The transmission characteristics of the multipath propagation (air, ice, and water) are investigated and reported.