New milestone announced in seafloor mapping
Celebrating collaborative efforts
Almost 30% of the world’s ocean floor has now been successfully mapped with approximately five million square kilometres of data added over the past year.
The Nippon Foundation-GEBCO Seabed 2030 Project this week confirmed a figure of 28.7% at the Assembly of the International Hydrographic Organisation (IHO), underway in Monaco.
The announcement also reflects a long-standing connection as the General Bathymetric Chart of the Oceans (GEBCO) was initiated in 1903 by Prince Albert I of Monaco – a pioneering oceanographer who recognised the need for a coordinated global effort to map the planet’s seafloor.
Bringing together delegations from 104 Member States, alongside observers from international organisations, maritime authorities and industry, the triennial Assembly provides an opportunity to review global progress in hydrography and set priorities for the years ahead.
The latest update represents approximately 104 million square kilometres of mapped seabed – an area equivalent to more than two-thirds of the Earth’s land surface. Over the past year alone, a further five million square kilometres of data have been incorporated into the GEBCO Grid.
This progress reflects ongoing contributions from a growing and increasingly diverse global community. A total of 220 organisations have now contributed, including 15 new contributors over the past year, with first-time data contributions from countries including Malaysia, Morocco, Papua New Guinea and Saudi Arabia, among others.
The 2026 update includes significant regional increases in mapped coverage. The ROPME Sea Area more than tripled in coverage, increasing from approximately 6.4% to 20.5%. Coverage also increased across the Eastern Atlantic, North Indian Ocean, Meso American and Caribbean Sea, and North Sea regions. At the national level, substantial increases were recorded within several Exclusive Economic Zones (EEZs).
Further highlights from the past year include the incorporation of a wide range of new and previously unshared datasets, including:
◼︎ Significant contributions from major data repositories, including NOAA-NCEI and PANGAEA.
◼︎ Expanded coastal mapping through datasets such as the Global Coastal SDB Dataset from Copernicus/EOMAP, adding new coverage in areas not represented in previous Grid releases.
◼︎ Notable satellite-derived bathymetry from the Greenwater Foundation, in partnership with TCarta and Caladan Oceanic.
◼︎ Additional bathymetric data from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), expanding coverage in the North Pacific.
◼︎ Deep-water mapping data from NOAA-led Seascape Alaska campaigns.
◼︎ Multibeam survey data contributed by the Directorate of Hydrography and Navigation of the Brazilian Navy.
◼︎ Multibeam data around the Comoros, contributed by the Bureau de Recherches Géologiques et Minières (BRGM), marking a new contributing organisation.
All data collected and shared with the Seabed 2030 project is included in the free and publicly available GEBCO global grid, supporting ocean science, policy and informed decision-making.
“The progress reflected in the 2026 Grid demonstrates what can be achieved through sustained international collaboration. At The Nippon Foundation, we are committed to supporting people and organisations working to deepen our understanding of the ocean, and to strengthening the connections between,” said Mitsuyuki Unno, Executive Director of The Nippon Foundation as he announced the new figure.
The Project is formally endorsed as a Decade Action of the UN Ocean Decade. GEBCO is a joint programme of the IHO and the Intergovernmental Oceanographic Commission (IOC) of UNESCO, and is the only organisation with a mandate to map the entire ocean floor.
“This update reflects what the global community can achieve when data is shared openly and collaboratively. Seabed 2030 exists to help bring those contributions together, and we are seeing that collective effort translate into meaningful results,” noted Seabed 2030 Director Jamie McMichael-Phillips.
PHOTO: Mapped seafloor shown in red and blue, with red indicating new bathymetric data added in the last year. (Credit: Seabed 2030)
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