GMRT Data Sources
GMRT brings together a variety of elevation sources which are delivered as multi-resolutional images and grids of land and ocean elevations. A mask layer is available that highlights the high-resolution data. We also keep track of cruises that we have reviewed but not included in the GMRT synthesis. To see a list of cruises currently being prepared for GMRT, click here. Please contact us if you would like to contribute data.
Source data in GMRT v4.5.0 include:
- Ship-based multibeam swath bathymetry data (100-m resolution) from research cruises assessed, cleaned, processed and curated by the GMRT Team. The current version (GMRT v4.5.0) was released in June 2026 and includes swath data from 1,644 cruises.
- Terrestrial elevation data (10-m resolution) for portions of the US from the USGS National Elevation Dataset (NED)
- Terrestrial elevation data (30-m resolution) from NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer global DEM (ASTER)
- Gridded seafloor depth data (variety of scales) contributed by the international science community
- Gridded seafloor depth data (15 arc-second resolution) from the General Bathymetric Chart of the Oceans (GEBCO 2026)
- Gridded seafloor depth data (2-km resolution) from the International Bathymetric Chart of the Arctic Ocean (IBCAO) version 2.23
- Gridded seafloor depth data and ice surface data (500 m resolution) from the International Bathymetric Chart of the Southern Ocean (IBCSO)
