Using data from NASA’s and European Space Agency’s satellites that measure variations in gravitational field, a multinational team of researchers led by Dr David Sandwell of Scripps Institution of Oceanography has produced a new map of the world’s seafloor, offering a much more vivid picture of the structures that make up the deepest, least-explored parts of the ocean.
North Atlantic; red dots are earthquakes. Image credit: David Sandwell / SIO.
The new map is based on data gathered by ESA’s CryoSat-2 satellite, which primarily captures polar ice data but also operates continuously over the oceans, and NASA’s Jason-1.
It reveals thousands of previously uncharted undersea mountains, or seamounts, extending a kilometer or more from the ocean bottom.
Combined with existing data and improved remote sensing instruments, it gives scientists powerful new tools for high-resolution exploration of regional seafloor structure and geophysical processes.
“The new map is twice as accurate as the previous version produced nearly twenty years ago,” Dr Sandwell and his colleagues said.
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 that were active 150 million years ago and are now buried by mile-thick layers of sediment.
Central Indian Ocean. Image credit: David Sandwell / SIO.
“One of the most important uses of the new data will be to improve the estimates of seafloor depth in the 80 percent of the oceans that remains uncharted or is buried beneath thick sediment,” said the scientists, who reported their results in today’s edition of the journal Science.
In addition, they discovered that seamounts and earthquakes, which were also mapped, are often linked.
Most seamounts were once active volcanoes, and so are usually found near tectonically active plate boundaries, mid-ocean ridges and subducting zones.
The new map also provides a foundation for the upcoming new version of Google’s ocean maps.
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David T. Sandwell et al. 2014. New global marine gravity model from CryoSat-2 and Jason-1 reveals buried tectonic structure. Science, vol. 346, no. 6205, pp. 65-67; doi: 10.1126/science.1258213
