REMOTE ACOUSTIC MONITORING OF MANGANESE NODULES ON THE OCEAN-BOTTOM

A wide set of experimental and theoretical investigations have been co nducted to find out acoustic properties of the deep-sea bottom covered with manganese nodules. The field experiments have been carried out i n four regions of the Pacific and Indian oceans at the frequency range 2-20 kHz with the aim to detect acoustically the presence of bottom n odules and to estimate their parameters. The theoretical model of soun d scattering and reflection by a set of nodules on the bottom has been developed, in which the explicit form of connection between character istics of bottom reradiated acoustic signals and nodules parameters ha ve been established. It made possible to explain all the obtained expe rimental data and to solve some inverse problems. The main results of the investigations are discussed and considered as the basis for acous tic monitoring of nodules deposits.