Method for determining seabed penetration depth in marine seismic exploration

Abstract

   The paper introduces a straightforward method aimed at determining the depth of penetration into the seabed during marine seismic exploration through bottom sounding. This technique was developed to support the establishment of technical specifications for the components of an underwater robotic complex intended for seismic surveys beneath ice formations. These components include a suite of autonomous underwater vehicles (AUVs) outfitted with either geophones or short streamers equipped with hydrophone sensors, alongside high-precision positioning systems. The complex comprises an underwater docking station responsible for deploying AUVs to the designated work area, managing their operations, and towing low-frequency sound emitters. Moreover, it encompasses coastal infrastructure dedicated to the maintenance of AUVs and the support of the docking station. The developed method considers various factors including the pressure exerted by the sound emitter and the energy dissipation of the probing signal due to wave front expansion, signal transmission into and back from the ground, spatial damping during signal propagation in water and soil, and reflection from oil or gas-containing lenses. Illustrative examples demonstrate the computation of ground penetration depth in shallow and deep waters, contingent upon the pressure exerted by the sound emitter towed at a depth of 100 meters. It also assesses the method’s reliability by comparing the computed outcomes against existing experimental data.