Seeing the seafloor in high definition: Modern mapping offers increasing clarity on Earth's vast underwater landscape

Fri, 20 May 2016 16:03:01 -0400

In the 1950s, Marie Tharp and Bruce Heezen, of what was then called the Lamont Geological Observatory, began creating seafloor maps based on single-beam sounding data from the U.S. Navy and other sources. Their compilation map of the global seafloor was published in 1977. Credit: Library of Congress, Geography and Map Division.

Gliding through pitch-black waters 50 meters off the ocean bottom, the “D. Allan B” can sense the seafloor below in striking clarity, despite the darkness. In its backyard off the California coast, the 5-meter-long, torpedo-shaped autonomous underwater vehicle (AUV) operated by the Monterey Bay Aquarium Research Institute (MBARI) has surveyed submarine topography ranging from deep canyons incising the continental shelf to subtle scarps weaving through blankets of ocean-bottom sediments. Since entering operation about a decade ago, the AUV’s mapping prowess — it can distinguish features less than a meter wide and just 10 centimeters tall, a level of precision that rivals NASA’s Mars-mapping HiRISE camera — has become an integral tool in MBARI’s efforts to study Earth’s surface beneath the waves.

Wealth of seafloor features emerges from new survey

Mon, 05 Jan 2015 19:54:58 -0500

A new survey of Earth’s deep ocean — 80 percent of which remains unmapped — has revealed a wealth of previously unknown features, including thousands of seamounts as well as a variety of undersea tectonic features that are either buried under too much sediment or were simply too small to be seen before. Researchers led by geophysicist David Sandwell of the Scripps Institution of Oceanography used high-resolution altimetry data from two Earth-observing satellites to produce a global marine gravity model that the team described in Science as twice as accurate as earlier incarnations.

Bathymetry on EARTH Magazine

Seeing the seafloor in high definition: Modern mapping offers increasing clarity on Earth's vast underwater landscape

Wealth of seafloor features emerges from new survey