Make A Map Of The Bottom Of An Ocean. The map was created by measuring the shape and gravity field of Earth using. Oceanographers use sonarsound wavesto map the ocean bottom.
Each consist of three sheets a base bathymetric map a magnetic map and a gravity map and where practicable a sediment overprint NOS 1308N-17S. Uses satellites to measures subtle but permanent differences in sea-surface height. See the coordinates of any place on earth by clicking the grid icon on the bottom left of the menu.
Uses multiple echo-soundings to map narrow 2-10 km sections of the ocean floor.
Two main methods are used to map the shape and depth of the seafloor. Beginning in 1957 Tharp and her research partner Bruce Heezen began publishing the first comprehensive maps that showed the main features of the ocean bottommountains valleys and trenches. The maps we create are a product of extensive scientific research. The actual physical bottom of the ocean or substrate is generally some type of rock or sediment and can be categorized as terrogenous biogenous or hydrogenous.
