What are these shadow lines on my terrain and how do I remove them?

Hey there and thanks for stopping by,

I’ve been teaching myself Unity and I’m currently playing around with Voxel/Minecraft style terrain generation for fun and experience. Today I’ve been playing with lighting and I’ve noticed an interesting issue- dark shadow lines form on my terrain at a distance. I’ve looked at my lighting settings, directional light settings, and shader settings a million times and I can’t figure out what might be causing them. Here’s a gfy of the issue: GIF | Gfycat

As you can see, as I get farther away, a shadow sort of moves down and covers the terrain, and then another one follows after it. I’m not moving the directional light or anything. What can I do to stop this from happening, or at least make it happen at a greater distance? It wouldn’t be noticeable if it was a bit farther away.

Thank you very much! Hopefully you can help me where googling could not. The only other issue I encountered that seemed similar was out of date and didn’t seem to get an adequate answer.

A shot in the dark:

It looks like that these “lines” of shadow are actually the cascades used in the shadow mapping that unity is using which is called Parallel Split Shadow Maps. My guess would be to increase either the shadow map resolution and or increase the amount of cascades. See these doc articles for further informations: this and that
But remember increasing the cascades and texture resolution can have a significant impact on performance.

The issue was related to my mipmap settings! The mipmaps generated caused the slightly darker effect. Thanks so much to everyone who looked at this, I appreciate it!