Variations in sea-floor relief may be depicted by color and contour lines called depth contours or isobaths.īathymetry is the foundation of the science of hydrography, which measures the physical features of a water body. In the same way that topographic maps represent the three-dimensional features (or relief) of overland terrain, bathymetric maps illustrate the land that lies underwater. The term 'bathymetry' originally referred to the ocean's depth relative to sea level, although it has come to mean “submarine topography,” or the depths and shapes of underwater terrain.
