A lot of things we think are static do actually change quite a bit. Tiny changes add up to a lot over time. I once buried a little canister with some money inside (in a shallow hole next to a distinctive tree) in the woods while hiking, just to see if anyone would find it. I came back a couple months later, took me a very long time to find, I did eventually, and it was much, much deeper than I had buried it. The soil must have shifted way more than I thought it would in that short period of time but it's not something you would ever notice from day to day.