The seabed has a complex layered structure in which one can distinguish a transitional layer of unconsolidated marine sediments bordering on the water. The transition layer, unlike the bury layers, is “active”. Bioturbation of benthic organisms has a profound effect on the physical and acoustic properties of marine sediments. Infauna is a type of benthos, whose organisms live directly inside the bottom sediments of rivers, lakes, ponds, seas. Burrowing, ingestion, digestion, defecation, tube building, change the porosity, grain size, bulk and shear properties of sediments. The article discusses the impact of certain types of infauna on the physical properties of precipitation. Within the framework of the GSEC theory of the propagation of elastic waves in marine sediments, the physical properties of the medium are restored from the measured frequency dependences of the speed of sound and the attenuation coefficient. The physical properties of the medium are associated with bioturbation. It is shown that bioturbation affects differently the physical properties of the medium, which determine the acoustic properties of the longitudinal and transverse waves. It is shown that the identification of bioturbation in the benthic boundary layer against the background of its general hydrodynamic variability is a difficult task.
marine sediments, phase-velocity dispersion, intergranular friction, attenuation coefficient, infauna, bioturbation
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