Peculiarities of Waves in Fast Ice in the Southwestern Sea of Okhotsk

Waves in the ice using the data of waves obtained by autonomous bottom recorders in the area of the southeastern shelf of Sakhalin Island from 2009 to 2017 is analyzed. It is shown that wave attenuation under the ice significantly depends on the period and increases as the period decreases. For waves with a period of 6 s, the weakening of energy is ~5.5 orders of magnitude compared to the open sea surface. The waves with a period of 500 s or greater attenuate insignificantly. A rise in the energy of the level fluctuations under the ice that refers to the range of infragravity (IG) waves is found for periods of 13–70 s. The analysis of wave propagation under the sea showed that the ice thickness and modulus of elasticity exert the strongest effect on wave dispersion.