Sediment Generated Noise in the Presence of Intense Internal Waves and Estimation of Bottom Parameters (vor Ort)
* Presenting author
As sediment generated noise (SGN) we understand irregular acoustic signals, generated by collisions and/or transport of sediment’s particles under influence of near bottom hydrodynamic perturbations/currents of different nature (in rivers, in tidal currents, in the presence of internal waves of large amplitude etc). The last one was found in framework of analysis of data of the Shallow Water 2006 experiment carried out in NJ shelf of USA, where trains of nonlinear internal waves (NIW) were registered and studied. Spectrum and intensity of SGN are demonstrated.Within the framework of Inman’s theory (Inman, J. of Sed. Petrol, 1949), it is shown that properties of SGN and threshold of velocity of near-bottom current, or value of NIW amplitude, exciting noise signal, are concerned with properties of sediment (size distribution and density of particles, etc). In particular usage of mentioned parameters of sediment, obtained by Goff et al , Mar. Geol. 2004, independently by direct measurements in area of experiment, for estimation of current/NIW amplitude threshold, give good agreement with the corresponding data of SW06. This circumstance gives the chance to use SGN characteristics in area of NIW activity for estimation of sediment’s parameters. Work was supported by RFBR, grant 20-05-00119.