system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: when someone walks in the snow, how come those footprints disappear when it snows again? Why aren’t the footprints always there, just with more inches of snow?
gpt
If the snow falls straight down sometimes you’ll still see the outline of the footprints.

Usually snow is accompanied by wind though, and the drifting snow fills in gaps and smooths out the surface layer again.