NASA's SWOT Satellite Reveals Unprecedented Detail of Earth's Ocean Floor Using Gravity Measurements

Summary

NASA has released a groundbreaking map of Earth's seafloor captured by the SWOT (Surface Water and Ocean Topography) satellite, a collaboration between NASA and France's CNES space agency. The satellite uses an ingenious gravity-based method to detect underwater terrain features by measuring subtle bumps in the ocean surface caused by the gravitational pull of seafloor formations like seamounts and ridges. This represents a major advancement in oceanographic mapping, as SWOT can detect seamounts smaller than half a kilometer—previously undetectable by older satellite technology—potentially increasing known seamount counts from 44,000 to 100,000.

Launched in December 2022, SWOT orbits Earth every 21 days and can cover 90% of the globe, providing unprecedented resolution compared to traditional ship-based sonar. The detailed seafloor mapping has practical applications including improved shipping routes, optimal placement of communications cables, detection of maritime hazards, and better understanding of ocean currents, tides, and plate tectonics. The research team, including geophysicist David Sandwell from Scripps Institution of Oceanography, published their findings in December 2024 and plans to continue calculating precise depths of newly identified features as part of a global initiative to achieve comprehensive seafloor mapping by 2030.

• Seafloor mapping applications include navigation optimization, infrastructure planning, hazard detection, and advancing knowledge of ocean ecosystems and plate tectonics