Scientists have created a new map of the world’s sea floor, accessing two previously untapped streams of satellite data to create a much more vivid picture of the structures which make up the deepest, least-explored parts of the ocean.
Thousands of previously uncharted sea mountains nd new clues about the formation of the continents have emerged through the new map, which is twice as accurate as the previous version produced nearly 20 years ago.
The new map extracts data from the European Space Agency’s (ESA) CryoSat-2 satellite which primarily captures polar ice data but also operates continuously over the oceans, and Jason-1, NASA’s satellite which was redirected to map the gravity field during the last year of its 12-year mission.
Combined with existing data and improved remote sensing instruments, the new map, described in the journal Science, has revealed details of thousands of undersea mountains, or seamounts, extending a kilometre or more from the ocean bottom.
The new map also gives geophysicists new tools to investigate ocean spreading centres and little-studied remote ocean basins.
“The kinds of things you can see very clearly now are abyssal hills, which are the most common land form on the planet,” said David Sandwell, lead scientist of the paper and a geophysics professor in the Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics at Scripps Institution of Oceanography.
Previously unseen features in the map include newly exposed continental connections across South America and Africa and new evidence for seafloor spreading ridges at the Gulf of Mexico which were active 150 million years ago and are now buried by mile-thick layers of sediment.
“One of the most important uses of this new marine gravity field will be to improve the estimates of seafloor depth in the 80% of the oceans that remains uncharted or is buried beneath thick sediment,” the authors say in the report.