Experimental analysis of flexural waves in river ice

Results of a full-scale experiment on reception of vibroacoustic signals excited in river ice by a pulsed source are discussed. The oscillograms of signals reveal the presence of air acoustic and bottom seismic waves, as well as flexural waves propagating in ice, which manifest themselves in the form of wave trains separated in arrival time. Experimental data are used to measure the group velocity and the damping decrement of flexural waves and the velocity of bottom-seismic waves. The theoretical estimate obtained for the group velocity of flexural waves in terms of the liquid-thin plate model agrees well with the value obtained from the experiment.