Oceanographers have a saying: Scientists know more about the surface of Mars than they do about the landscape at the bottom of our oceans. But that may soon change. Using data from satellites that measure variations in Earth’s gravitational field, researchers have found a new and more accurate way to map the sea floor. The improved resolution has already allowed them to identify previously hidden features—including thousands of extinct volcanoes more than 1000 meters tall—as well as piece together some lingering uncertainties in Earth’s ancient history.
Roughly 90% of the deep-ocean sea floor remains unmapped, a fact that’s been thrown into sharp relief by searchers’ inability to locate Malaysia Airlines Flight 370, which is thought to have crashed somewhere in the southern Indian Ocean in March. What maps do exist have been largely generated by instruments such as ship-based multibeam sonar systems, which take soundings of the depth to the sea floor as they crisscross select areas of ocean. That leaves “big holes hundreds of kilometers across with no data,” says David Sandwell, a geophysicist at the Scripps Institution of Oceanography in San Diego, California
via Satellites reveal hidden features at the bottom of Earth’s seas | Science/AAAS | News.
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