"Scientists have devised a new map of the Earth's seafloor using satellite data, revealing massive underwater scars and thousands of previously uncharted sea mountains residing in some of the deepest, most remote reaches of the world's oceans.

The researchers said on Thursday they used gravity measurements of the seafloor from radar equipment aboard the European Space Agency's CryoSat-2 satellite and NASA's Jason-1 satellite to capture underwater geological features in unprecedented detail.

"The pull of gravity reflects the topography and tectonics of the seafloor," said David Sandwell, a geophysicist at Scripps Institution of Oceanography at the University of California, San Diego who led the study.

University of Sydney geophysicist Dietmar Müller, another of the researchers, said about 71 percent of the Earth's surface is covered by water and roughly 90 percent of the seafloor is uncharted by survey ships that employ acoustic beams to map the depths."

Will Dunham reports for Reuters October 3, 2014. [2]