Prospects of hydroacoustic detection of ultra-high and extremely high energy cosmic neutrinos

The prospects of construction of deep underwater neutrino telescopes in the world’s oceans for the goals of ultra-high and super-high energy neutrino astrophysics (astronomy) using acoustic technologies are reviewed. The effective detection volume of the acoustic neutrino telescopes can be far greater than a cubic kilometer for extreme energies. In recent years, it was proposed that an existing hydroacoustic array of 2400 hydrophones in the Pacific Ocean near Kamchatka Peninsula could be used as a test base for an acoustic neutrino telescope SADCO (Sea-based Acoustic Detector of Cosmic Objects) which should be capable of detecting acoustic signals produced in water by the cosmic neutrinos with energies $1019–21 eV$ (e.g., topological defect neutrinos). We report on simulations of super-high energy electron-hadron and electron-photon cascades with the Landau-Pomeranchuk-Migdal effect taken into account. Acoustic signals emitted by neutrino-induced cascades with energies $1020–21 eV$ were calculated. The possibilities of using a converted hydroacoustic station MG-10 $(MG-10M)$ of 132 hydrophones as a basic module for a deep water acoustic neutrino detector with the threshold detection energy $1015 eV$ in the Mediterranean Sea are analyzed (with the aim of searching for neutrinos with energies $1015–16 eV$ from Active Galactic Nuclei).