GEBCO Earth Reliefs
Usage
You access the GEBCO global relief grid by specifying the special name
@earth_gebco[_rru[_reg]]
This grid only contains observed relief and inferred relief via altimetric gravity. A second grid that gives sub-ice (si) elevations is also available and can be accessed via
@earth_gebcosi[_rru[_reg]]
and is the one displayed above. The following codes for rru and the optional reg are supported (dimensions are listed for pixel-registered grids; gridline-registered grids increment dimensions by one):
Code
Dimensions
Reg
Size
Description
01d
360 x 180
g,p
103 KB
1 arc degree global relief (GEBCO 2024 @ 315 km)
30m
720 x 360
g,p
350 KB
30 arc minute global relief (GEBCO 2024 @ 157 km)
20m
1080 x 540
g,p
729 KB
20 arc minute global relief (GEBCO 2024 @ 105 km)
15m
1440 x 720
g,p
1.3 MB
15 arc minute global relief (GEBCO 2024 @ 79 km)
10m
2160 x 1080
g,p
2.7 MB
10 arc minute global relief (GEBCO 2024 @ 52 km)
06m
3600 x 1800
g,p
7.1 MB
6 arc minute global relief (GEBCO 2024 @ 32 km)
05m
4320 x 2160
g,p
10 MB
5 arc minute global relief (GEBCO 2024 @ 26 km)
04m
5400 x 2700
g,p
16 MB
4 arc minute global relief (GEBCO 2024 @ 21 km)
03m
7200 x 3600
g,p
27 MB
3 arc minute global relief (GEBCO 2024 @ 16 km)
02m
10800 x 5400
g,p
58 MB
2 arc minute global relief (GEBCO 2024 @ 11 km)
01m
21600 x 10800
g,p
211 MB
1 arc minute global relief (GEBCO 2024 @ 1.9 km)
30s
43200 x 21600
g,p
752 MB
30 arc second global relief (GEBCO 2024 @ 2.6 km)
15s
86400 x 43200
p
2.6 GB
15 arc second global relief (GEBCO 2024 original)
03s
432000 x 216000
g
6.8 GB
3 arc second global relief (SRTM3S original)
01s
1296000 x 432000
g
41 GB
1 arc second global relief (SRTM1S original)
Note that resolutions 05m and higher are tiled. See Remote Data Sets for more information.
See GMT remote dataset usage for when resolution codes are optional or required.
All of these data will, when downloaded, be placed in your ~/.gmt/server directory, with
the earth_gebco files being placed in an earth/earth_gebco sub-directory,
and earth_gebcosi files in an earth/earth_gebcosi sub-directory. If you
do not specify a CPT then the default CPT (the GMT master geo CPT) will be used.
Technical Information
As you see, the 30s and lower resolutions are all derivatives of GEBCO’s 2024 15 arc second grids (GEBCO_Compilation_Group, 2024). We have downsampled it via Cartesian Gaussian filtering to prevent aliasing while preserving the latitude-dependent resolution in the original 15 arc sec grid. The full (6 sigma) filter-widths are indicated in parenthesis. The 3 and 1 arc second data are the SRTM 1x1 degree tiles from NASA. Note: The 3 and 1 arc second grids only extend to latitudes ±60˚ and are only available over land. When these grids are accessed as @earth_gebco_01s or @earth_gebco_03s we will automatically up-sample the relevant @earth_gebco_15s tiles to fill in the missing ocean values. If you just want the original land-only SRTM tiles you may use the special names @srtm_relief_03s or @srtm_relief_01s instead. Almost all grids are available in both gridline- and pixel-registered formats except the original pixel-registered GEBCO 2024 (here called @earth_gebco_15s) and the gridline-registered SRTM tiles.
Data References
GEBCO Compilation Group (2024) GEBCO 2024 Grid (https://doi.org/10.5285/1c44ce99-0a0d-5f4f-e063-7086abc0ea0f)
SRTMGL3 tiles: [https://lpdaac.usgs.gov/products/srtmgl3v003].
SRTMGL1 tiles: [https://lpdaac.usgs.gov/products/srtmgl1v003].