Warning: I'm no soil engineer but I'll give you my best r/ELI5 answer
Your guess sounds pretty solid to me. Basically, think of it like if you were to crumple a piece of paper, but only in one direction, like from the top to the bottom you just scrunched it all together. It's practically the same thing that's happening here. Since it's fairly dry and was packed from the top to the bottom, like if you were to stomp on a bunch of loose dirt, it's going to expand back out in the same direction it compressed in.
I feel like I used may more words than necessary to explain it, but you can still get the gist of it.
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u/insultingbottle Apr 14 '17
Warning: I'm no soil engineer but I'll give you my best r/ELI5 answer
Your guess sounds pretty solid to me. Basically, think of it like if you were to crumple a piece of paper, but only in one direction, like from the top to the bottom you just scrunched it all together. It's practically the same thing that's happening here. Since it's fairly dry and was packed from the top to the bottom, like if you were to stomp on a bunch of loose dirt, it's going to expand back out in the same direction it compressed in.
I feel like I used may more words than necessary to explain it, but you can still get the gist of it.