Seabed mapping

Abstract

Navigational charts are the marine equivalent to topographic maps. Both use measures of height/depth points and outlines to depict an image. The arrival of multibeam hydrographic echo sounders in the early eighties marked a true revolution in seabed mapping, achieving results for marine measurements almost equivalent to those obtained on land. There came a change from validating specific data to having a continuous registration of the seabed. These technologies have even indirectly made it possible to obtain a highly precise verification of the composition of the marine seabed with errors smaller than 10 centimetres. The equipments for bathymetric studies are installed in ships arranged for mapping the seabed. These are usually oceanographic ships for mapping deep waters and small-size boats for shallow waters. In the first case, the detailed studies of deep zones serve as an important research component, whereas in the case of bathymetries for coastal or shallow waters, the foundation is more technical, as in the case of navigable channels, which must be periodically dredged, of harbour works, regeneration of beaches, etc.