|New satellite radar could find 100,000 underwater mountains|In: Science (Washington). American Association for the Advancement of Science: New York, N.Y. ISSN 0036-8075, more
With only about 10% of the sea floor mapped with high-resolution sonar from ships, scientists assembling global maps have to rely on an indirect method: using orbiting radar satellites to trace subtle bumps and depressions in the water surface, which mirror the shape of the sea floor. Even the most advanced map made by that technique has trouble identifying and locating seamounts less than 2 kilometers tall. But a new study demonstrates how a French radar instrument on an Indian satellite could greatly enhance seamount maps, putting submariners on safer courses while helping with climate science, fisheries science, and tsunami forecasts. Tests in the Pacific Ocean showed that the instrument, a radar altimeter called AltiKa, can spot seamounts as small as 1 kilometer tall. Researchers say it could boost the number of known seamounts from 10,000 to 100,000.