Global Earth Relief Grids
Usage - Global Earth Relief Grids
You access a global relief grid by specifying the special name
@earth_relief_rru[_reg]
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 |
128 KB |
1 arc degree global relief (SRTM15+V2.1 @ 111 km) |
30m |
720 x 360 |
g,p |
435 KB |
30 arc minute global relief (SRTM15+V2.1 @ 55 km) |
20m |
1080 x 540 |
g,p |
918 KB |
20 arc minute global relief (SRTM15+V2.1 @ 37 km) |
15m |
1440 x 720 |
g,p |
1.6 MB |
15 arc minute global relief (SRTM15+V2.1 @ 28 km) |
10m |
2160 x 1080 |
g,p |
3.4 MB |
10 arc minute global relief (SRTM15+V2.1 @ 18 km) |
06m |
3600 x 1800 |
g,p |
8.8 MB |
6 arc minute global relief (SRTM15+V2.1 @ 10 km) |
05m |
4320 x 2160 |
g,p |
13 MB |
5 arc minute global relief (SRTM15+V2.1 @ 9 km) |
04m |
5400 x 2700 |
g,p |
19 MB |
4 arc minute global relief (SRTM15+V2.1 @ 7.5 km) |
03m |
7200 x 3600 |
g,p |
33 MB |
3 arc minute global relief (SRTM15+V2.1 @ 5.6 km) |
02m |
10800 x 5400 |
g,p |
71 MB |
2 arc minute global relief (SRTM15+V2.1 @ 3.7 km) |
01m |
21600 x 10800 |
g,p |
258 MB |
1 arc minute global relief (SRTM15+V2.1 @ 1.9 km) |
30s |
43200 x 21600 |
g,p |
935 MB |
30 arc second global relief (SRTM15+V2.1 @ 1.0 km) |
15s |
86400 x 43200 |
p |
3.2 GB |
15 arc second global relief (SRTM15+V2.1) |
03s |
432000 x 216000 |
g |
6.8 GB |
3 arc second global relief (SRTM3S) |
01s |
1296000 x 432000 |
g |
41 GB |
1 arc second global relief (SRTM1S) |
All of these data will, when downloaded, be placed in your ~/.gmt/server directory, with
the earth_relief files being placed in an earth/earth_relief sub-directory. If you
do not specify a CPT then this dataset default to the GMT master geo.
Technical Information - Global Earth Relief Grids
As you see, the 30s and lower resolutions are all derivatives of Scripps’ SRTM15+V2.1 grid (Tozer et al., 2019). 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_relief_01s or @earth_relief_03s we will automatically up-sample the relevant @earth_relief_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 SRTM15+V2.1 (here called @earth_relief_15s) and the gridline-registered SRTM tiles.
Data References - Global Earth Relief Grids
SRTM15+V2.1: [http://dx.doi.org/10.1029/2019EA000658].
SRTMGL3 tiles: [https://lpdaac.usgs.gov/products/srtmgl3v003].
SRTMGL1 tiles: [https://lpdaac.usgs.gov/products/srtmgl1v003].