GMT 6.1.0 has been released!

The GMT Team is wishing you a happy 4th of July which happens to coincide with the long-awaited release of GMT 6.1.0!

Apart from innumerable bug-fixes, better documentation, and other simplifications, this version adds four new modules (batch, grdmix, grdinterpolate, and grdgdal), strengthens modern mode in various ways (such as automatic legend generation from plot, plot3d, and the contouring tools), and offers a series of enhancements to existing modules. In addition, we have expanded the remote dataset service to provide updated global DEMs from SRTM152.1+ and making available three new global data sets: Seafloor crustal ages [from EarthByte], land/ocean masks [via GSHHG], and day/night images of the Earth from the Blue and Black Marbles [from NASA]. For more details about the datasets, see here.

GMT 6.1.0 is a recommended upgrade for all users, and new installers are available from For more information, see the ChangeLog.

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This is great news about the GMT 6.1.0 release. I was reading about the global DEMs in the web page, and it says the 1-arcsecond and 3-arcsecond DEMs are from NASA, but the link to information on the SRTM version used is broken. The reprocessed SRTM data that is officially called NASADEM was officially released in February 2020. It was in a temporary status for more than a year before that. This is the NASADEM release announcement:

Thanks Eric, I ended up using their links to the SRTMGL? pages

#. SRTMGL3 tiles: [].
#. SRTMGL1 tiles: [].

since I am not sure if the NASADEM files differ - will have to check a few. Also, the nasadem does not mention 3s.

OK, so you are using the previously released SRTM version 3 DEM products. It would be good to specify that version.
There are many improvements in the new NASADEM at both local and continental scales. They reprocessed the original SRTM raw data with updated continental reference information from Icesat-1 and Icesat-2 and improved the phase unwrapping and void filling in high-relief areas, among other things. The voids in the SRTM data are filled with an edited versions of several other DEMs. The differences are largest in mountains and canyons, including the Grand Canyon. The file format is the same, but I think they made a subtle change to the file naming. I thought they released both a 1-arcsecond and 3-arcsecond version but I am not sure.

Thanks for the info, Eric, when I find some time I will download some tiles and check if I got an early-release of these or not. If new then I can update on our server.

It is a little confusing, because there were two different NASA Measures projects to improve the SRTM DEM products. The first project resulted in the SRTM version 3 released in 2015 that had void filling but was still the originally processed SRTM elevation data (done with support from NGA) outside of the voids. The second project did a complete reprocessing from the raw SRTM data to make the NASADEM. They changed the name to in part to make it clear that NASADEM is fully reprocessed completely by NASA without any restrictions that were earlier imposed by NGA. Some background is described here: