Extra correct maps primarily based on knowledge from the SWOT mission can enhance underwater navigation and end in higher information of how warmth and life transfer all over the world’s ocean.
There are higher maps of the Moon’s floor than of the underside of Earth’s ocean. Researchers have been working for many years to alter that. As a part of the continuing effort, a NASA-supported crew lately revealed probably the most detailed maps but of the ocean ground, utilizing knowledge from the SWOT (Floor Water and Ocean Topography) satellite tv for pc, a collaboration between NASA and the French house company CNES (Centre Nationwide d’Études Spatiales).
Ships outfitted with sonar devices could make direct, extremely detailed measurements of the ocean ground. However up to now, solely about 25% of it has been surveyed on this means. To supply a worldwide image of the seafloor, researchers have relied on satellite tv for pc knowledge.
NASA’s Scientific Visualization Studio
Extra correct maps of the ocean ground are essential for a variety of seafaring actions, together with navigation and laying underwater communications cables. “Seafloor mapping is essential in each established and rising financial alternatives, together with rare-mineral seabed mining, optimizing delivery routes, hazard detection, and seabed warfare operations,” mentioned Nadya Vinogradova Shiffer, head of bodily oceanography applications at NASA Headquarters in Washington.
Correct seafloor maps are additionally necessary for an improved understanding of deep-sea currents and tides, which have an effect on life within the abyss, in addition to geologic processes like plate tectonics. Underwater mountains known as seamounts and different ocean ground options like their smaller cousins, abyssal hills, affect the motion of warmth and vitamins within the deep sea and may entice life. The consequences of those bodily options may even be felt on the floor by the affect they exert on ecosystems that human communities rely upon.
Mapping the seafloor isn’t the SWOT mission’s main objective. Launched in December 2022, the satellite tv for pc measures the peak of water on almost all of Earth’s floor, together with the ocean, lakes, reservoirs, and rivers. Researchers can use these variations in peak to create a type of topographic map of the floor of fresh- and seawater. This knowledge can then be used for duties similar to assessing adjustments in sea ice or monitoring how floods progress down a river.
“The SWOT satellite tv for pc was an enormous leap in our skill to map the seafloor,” mentioned David Sandwell, a geophysicist at Scripps Establishment of Oceanography in La Jolla, California. He’s used satellite tv for pc knowledge to chart the underside of the ocean because the Nineties and was one of many researchers chargeable for the SWOT-based seafloor map, which was revealed within the journal Science in December 2024.
The examine authors relied on the truth that as a result of geologic options like seamounts and abyssal hills have extra mass than their environment, they exert a barely stronger gravitational pull that creates small, measurable bumps within the sea floor above them. These refined gravity signatures assist researchers predict the type of seafloor characteristic that produced them.
Via repeated observations — SWOT covers about 90% of the globe each 21 days — the satellite tv for pc is delicate sufficient to choose up these minute variations, with centimeter-level accuracy, in sea floor peak attributable to the options under. Sandwell and his colleagues used a 12 months’s value of SWOT knowledge to deal with seamounts, abyssal hills, and underwater continental margins, the place continental crust meets oceanic crust.
Earlier ocean-observing satellites have detected huge variations of those backside options, similar to seamounts over roughly 3,300 toes (1 kilometer) tall. The SWOT satellite tv for pc can choose up seamounts lower than half that peak, doubtlessly growing the variety of recognized seamounts from 44,000 to 100,000. These underwater mountains stick up into the water, influencing deep sea currents. This may focus vitamins alongside their slopes, attracting organisms and creating oases on what would in any other case be barren patches of seafloor.
The improved view from SWOT additionally offers researchers extra perception into the geologic historical past of the planet.
“Abyssal hills are essentially the most ample landform on Earth, overlaying about 70% of the ocean ground,” mentioned Yao Yu, an oceanographer at Scripps Establishment of Oceanography and lead writer on the paper. “These hills are just a few kilometers large, which makes them arduous to look at from house. We had been stunned that SWOT may see them so properly.”
Abyssal hills kind in parallel bands, just like the ridges on a washboard, the place tectonic plates unfold aside. The orientation and extent of the bands can reveal how tectonic plates have moved over time. Abyssal hills additionally work together with tides and deep ocean currents in ways in which researchers don’t totally perceive but.
The researchers have extracted almost all the knowledge on seafloor options they anticipated to search out within the SWOT measurements. Now they’re specializing in refining their image of the ocean ground by calculating the depth of the options they see. The work enhances an effort by the worldwide scientific group to map your entire seafloor utilizing ship-based sonar by 2030. “We gained’t get the total ship-based mapping accomplished by then,” mentioned Sandwell. “However SWOT will assist us fill it in, getting us near reaching the 2030 goal.”
The SWOT satellite tv for pc was collectively developed by NASA and CNES, with contributions from the Canadian Area Company (CSA) and the UK Area Company. NASA’s Jet Propulsion Laboratory, managed for the company by Caltech in Pasadena, California, leads the U.S. element of the venture. For the flight system payload, NASA supplied the Ka-band radar interferometer (KaRIn) instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. The Doppler Orbitography and Radioposition Built-in by Satellite tv for pc system, the twin frequency Poseidon altimeter (developed by Thales Alenia Area), the KaRIn radio-frequency subsystem (along with Thales Alenia Area and with assist from the UK Area Company), the satellite tv for pc platform, and floor operations had been supplied by CNES. The KaRIn high-power transmitter meeting was supplied by CSA.
To study extra about SWOT, go to:
Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
2025-040
