I came across a map of the earth that left me almost breathless, as breathless as a map can make you

I have several questions regarding it, but for the sake of simplicity I'll narrow it down to the main ones:

1. Are their any tutorials or tips to create mountains in GIMP or Photoshop as they are on this map?

2. Also, the terrain blending is obviously fantastic. Any tuts/tips on this?

This might be a satellite image, but I get the sense that it isn't. Any help with my questions would be great, thanks!

Here's the map; http://naturalearth.springercarto.co..._clouds_8k.jpg