"when one showing exactly what they are talking about exists in a press release from the European Geosciences Union they link to in their own article?"
Cus you can't just jack photos without permission ?
Cus you can't just jack photos without permission ?
Indeed. The origin of the image is the German Research Centre for Geosciences (GFZ Potsdam, http://icgem.gfz-potsdam.de/home) which has approved use of a very similar render under Creative Commons Attribution (cc-by) as noted in its wikipedia page: https://en.wikipedia.org/wiki/File:Geoid_undulation_10k_scal...
The source of this picture is their interactive renderer: http://icgem.gfz-potsdam.de/vis3d/longtime
The author of the blog post from the European Geosciences Union was at the time a postdoc at GFZ Potsdam.