I have not the possibility to make a testrender. But the height above surface is about 12m. At first sight.
Looking at the nodes of the crack-function, I am amazed by the delicate use of scale.
Everything is calm - displacements of -0.5 to 1.0.
The Warping-The-Cracks node has a displacement of 30. I am not sure if it works only lateral. I rather guess that it goes vertical, too.
In other words you might be sitting within a displacement.
Reducing the warper's displacement 5 should be fine.
Just a guess.
Volker