We recently got the idea of trying to see if we could see sand dunes moving using Google Earth historical imagery. The biggest problem is that for the best results we needed frequent satellite imagery over as long a time period as possible, but most deserts have very little satellite imagery. Google Earth imagery tends to focus on populated areas, so we looked for towns that have sand dunes on the outskirts. We started with Nouakchott, the capital of Mauritania. We had come across this article, which suggests that Nouakchott may be slowly obliterated by creeping sand dunes. But what we found, in the places we looked, was that the opposite was the case – the city was slowly taking over the sand dunes.
We recommend watching the videos full screen.
We tried a little to the east of Nouakchott and, since the image jumps around quite a lot due to poor image alignment in Google Earth, we cannot definitively say which way the dunes are moving, if at all. They do change shape quite considerably in the first few frames:
Next we tried Namibia and chose some sand dunes just east of Lüderitz. This time there is no doubt that the dunes are moving northwards.
We also looked at sand dunes east of Oranjemund, also in Namibia. There isn’t much imagery and it gets updated in sections, but the overall movement is still clear. If it wasn’t for the town of Oranjemund staying in one place you might think the sand was stationary and the imagery was just being moved.
Still in Namibia, we go to Walvis Bay and here we can see dunes slowly moving north-west.
You can download the Google Earth tours used to create the above videos.
To create the above videos we used our advanced Google Earth historical imagery tour maker and Google Earth Pro’s built-in Movie Maker.
We presume that how fast sand dunes move depends on many factors, including wind speeds, dune size and grain size.