Acoustic characteristics of the seismic airgun sound propagation in the East Siberian Sea

A passive acoustic monitoring has been conducted by Korea Polar Research Institute (KOPRI) since 2017 in the East Siberian Sea using an autonomous passive acoustic recorder. Seismic airgun sounds, generated from the multichannel seismic survey system of the ice-breaking research vessel Araon, were measured from 18.6 km to 164.2 km in September 2019. During the survey, the R/V Araon maintained the ship’s trajectory at a constant heading and speed to obtain useful acoustic data for investigating the acoustic propagation properties with a distance between the source and receiver in shallow water. The decrease in sound pressure levels as a function of distance was compared with the least-square regression curves and numerical propagation modeling based on the parabolic equation. The broadband sounds in a low-frequency range were propagated over long distances with distinctive characteristics such as precursor arrivals, modal dispersion, and rapid decrease in spectrum level at low frequencies. Our results will be discussed in comparison with the sediment structure and geological history of the measurement region. [This research was supported by Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries (20210605, Korea-Arctic Ocean Warming and Response of Ecosystem, KOPRI and 20210632, Survey of Geology and Seabed Environmental Change in the Arctic Seas, KOPRI).]