Thanks for looking up and trying this effect.
Also it may not be the only way to create this effect and if you find any other possibilities of this effect feel free to write me.
I think this is not actually a tutorial, we can call it as a "How to".
The 4000x3000 render of this effect with registered version of Terragen, took 01:09:00 (1 hours 9 minutes) on an AMD Athlon XP 1700+
Let's pass to the settings for this effect.