Global Seafloor Map Reveals Stunning Details Of Earth's Depths

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 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.


The map reveals major seafloor and sub-seafloor structures.

They include a mid-ocean ridge beneath the Gulf of Mexico with a length about equal to the width of Texas as well as another ridge under the South Atlantic west of Angola about 500 miles (800 km) long that was formed just after the continent of South America separated from Africa. 

Such "spreading ridges" are cracks in the Earth formed where the planet's tectonic plates moved apart and molten material called magma came up to fill them, the researchers said.

Müller said the conclusions the researchers made about seabed topography may be less accurate than acoustic beam methods employed by ships.

CryoSat-2 was dedicated to monitoring changes in the thickness of marine ice floating in the polar oceans and variations in the thickness of the vast ice sheets that overlie Greenland and Antarctica. Jason-1 was dedicated to map the change in the topography of the oceans due to ocean currents.



REUTERS