Given the text: To investigate the subsoil in water areas Patzold, Köbke Engineers GmbH & Co. KG uses e.g. shallow seismic techniques (sub-bottom profiling). This integrates parametric sediment echosounders and towed systems such as Boomer and Chirp which are able to explore the structural substratum to a penetration up to 50 m, depending on type of sediment. Under certain conditions shallow seismics is also suitable for detection of buried objects such as boulders or wrecks. In seismogram, identified strata or layers can be correlated with exploration drillings such as vibrocores (VC) or else cone penetration test (CPT) to construct a subsoil technical model. For investigations on land geotechnical methods such as percussion drillings and dynamic penetrations are essentially used, but also geophysical methods such as geo-radar or geoelectrics can be applied. Compared to geo-radar, geoelectrics can penetrate the groundwater level and cohesive ground and is also applicable on water areas, e.g. to identify stratigraphic boundaries below the seabed.
How does shallow seismic techniques such as sub-bottom profiling help in exploring the structural substratum of water areas? Are there any other geophysical methods that can be used for subsoil investigation?
This prompt doesn't seem malicious.