The initiative that seeks to galvanise the creation of a full map of the ocean floor says one-fifth of this task has now been completed.
When the Nippon Foundation-GEBCO Seabed 2030 Project was launched in 2016, only 6% of the global ocean bottom had been surveyed to what might be called modern standards.
Some 14.5 million sq km of new bathymetric (depth) data was included in the GEBCO grid in 2019 – an area equivalent to almost twice that of Australia.
“Today we stand at the 19% level. That means we’ve got another 81% of the oceans still to survey, still to map. That’s an area about twice the size of Mars that we have to capture in the next decade,” project director Jamie McMichael-Phillips told BBC News.
Black represents those areas where we have yet to get direct echosounding measurements of the shape of the ocean floor. Blues correspond to water depth (deeper is purple, shallower is lighter blue).
It’s not true to say we have no idea of what’s in the black zones; satellites have actually taught us a great deal. Certain spacecraft carry altimeter instruments that can infer seafloor topography from the way its gravity sculpts the water surface above – but this only gives a best resolution at over a kilometre, and Seabed 2030 has a desire for a resolution of at least 100m everywhere.