What I want to do is have the animation start at the bottom of the composition, with the cracks closer together, then flow up to the top while the space between the cracks expands. Here is a sloppy example I made: https://i.imgur.com/dR7TnVS.png
It doesn't need to be as intricate as this. I would also like to find a way to loop the animation (15 seconds), so the "texture" should repeat.
Any ideas on how I could achieve this? I was thinking fractal noise of some kind and simply warping it so it becomes larger at the top, but after messing around for a bit I couldn't figure out how to make the fractal noise into cracks.