This is the most detailed map of the seafloor ever made.

The ocean still holds many secrets to discover. Despite significant advances in technology, the ocean's surface remains less well known than the surface of the Moon. That's why the NASA-CNES SWOT (surface water and ocean topography) satellite is so interesting.

SWOT completed its seafloor mapping in just one year after launching in December 2022. The map has a resolution of 8 km, surpassing 30 years of data from previous satellites. Researchers discovered 'thousands of abyssal hills and underwater volcanoes' that had never been recorded before.

Previously, most underwater surveys relied on satellite altimetry, which infers seafloor topography from variations in ocean surface elevation. Seamounts, for example, alter local gravity, causing water to accumulate above them. However, SWOT improves on this technique by measuring variations in two dimensions, which can help distinguish previously unknown geological structures.