depths
131Earth exploration — Introduction the investigation of the surface of the Earth and of its interior. By the beginning of the 20th century most of the Earth s surface had been explored, at least superficially, except for the Arctic and Antarctic regions. Today the… …
132undersea exploration — Introduction the investigation and description of the ocean waters and the seafloor and of the Earth beneath. Primary objectives and accomplishments Included in the scope of undersea exploration are the physical and chemical… …
