GEBCO Bathymetric Contours (NOAA NCEI Visualization)

This tiled map service displays bathymetric contours derived from the General Bathymetric Chart of the Oceans GEBCO_2024 grid, which is a global bathymetry compilation at 15 arc-second resolution. Depths are displayed in meters. At large scales (1:5,000,000 and closer), the contour interval is 500m; at medium scales (1:5,000,000 to 1:30,000,000) the contour interval is 1000m; and at small scales (1:30,000,000 and greater), the contour interval is 2000m. Supplementary contours are shown in shallow waters (less than 500m). A "smoothing" process was done in ArcGIS Pro to generate these contours: Create a version of the GEBCO grid using the Convolution raster function "Smoothing 3x3" option. Generate contours at selected intervals using "Contour List". Generalize the contours using "Simplify Line" with a tolerance of 0.005 degrees. These contours are also available as a downloadable file geodatabase. Please also see NOAA/NCEI's color shaded-relief visualization of the GEBCO grid. See here for a map with both hillshade and contours included.