Aquatic ecology researchers have long been exploring the oceans to discover the mysteries of the aquatic ecosystems far below the surface of the water, piecing together a picture of just what these subterranean worlds look like. Now, we have a more comprehensive look at the bottom of the ocean, as scientists have created the most detailed map of the seafloor ever produced.
How was the mapping data gathered?
The map was published in the journal Science as part of a study conducted in collaboration by scientists at the University of Sydney, the National Oceanic and Atmospheric Administration, Scripps Institution of Oceanography and the European Space Agency.
It was developed using data from satellites measuring the variations of the gravitational field of Earth. These space instruments bounce signals off of the surface of the ocean, and this recurring pinging, after being analyzed and corrected for waves and tides, provides a picture of its overall topography of the ocean floor, including underwater hills and valleys.
For instance, the satellites revealed thousands of seamounts (extinct volcanoes rising from the floor of the ocean), as David Sandwell, a geophysicist at the Scripps Institution of Oceanography in San Diego, California, explained to Science.
"A seamount, for example, exerts a gravitational pull, and warps the sea surface outward," he says. "So we can map the bottom of the ocean indirectly, using sea-surface topography."
The two satellites utilized for this project were NASA's Jason-1 and the European Space Agency's CryoSat-2, which are capable of taking images with sharper focus than those used to create the last version from almost two decades ago. For example, CryoSat-2 has a high-range precision altimeter and four years worth of data, more than any other information-gathering projects. As geophysicist Paul Wessel, a geophysicist at the University of Hawaii, Manoa, told Science, it's a huge advancement in ocean mapping technology.
"[The study authors] have dramatically improved the signal-to-noise ratio in their marine gravity grid, allowing very subtle features to be resolved," Wessel said. "This work brings home the importance of collecting new data, as well as applying expert processing to older data – squeezing out more information than was thought possible."
How can researchers use this map?
The map provides vivid images of the least-explored parts of the ocean, providing scientists with a new tool to discover uncharted parts of the ocean. This could be used to direct aquatic ecology researchers to remote ocean basins where new marine life may be waiting to be discovered. It also gives scientists clues about the formation of the continents and will serve as the basis for the Google's ocean maps.
"One of the most important uses will be to improve the estimates of seafloor depths in the 80 percent of the oceans that remain uncharted or [where the sea floor] is buried beneath thick sediment," the study authors wrote, according to ECO Magazine.