MAPPING THE SEA-FLOOR FROM SPACE

Highly sensitive radar altimeters in Earth orbit sense minute changes in sea level caused by the gravitational attraction of topography on t he seafloor. Algorithms that predict the shape of the seafloor implied by the altimeter data allow researchers, for the first time, to produ ce detailed maps of the largely unexplored Southern Oceans, These new charts have found a number of applications, such as in finding new fis hing grounds on shallow submarine banks, improving estimates of the in ventory of submarine volcanism, determining the azimuths of faults whi ch mark the past and present drift of tectonic plates, and planning be tter oceanographic expeditions.