The soil here is mostly mixed sand and clay, liberally sprinkled with pebbles and larger rocks. And at the start of every winter, as soon as there’s a rain or snow immediately followed by a ground freeze, the pebbles all look like they’re trying to burrow underground and hibernate.

And it stays that way all winter, renewing itself every daily thaw and every nightly freeze, until spring when the ground stops heaving, dries out and slumps back to normal.
















































Hoarfrost. The ground freezes and expands upward, making the rocks look like they’re going down. It can get pretty intense around here. I’ve seen crystals four inches high.
I’ve always heard it called frost heave. Might be a regional name. The moisture in the soil freezes and expands. The expansion follows the path of least resistance which is around the rocks and upward.
Yeah, it’s called frost heaving in Michigan, too.
Yep, exactly the same here in Alaska. Frost heave is entertaining enough there are plenty of areas where the roadways become nothing but a series of rolling bumps.
Hoarfrost is when moisture precipitates directly from the air.
This is frost heave with a touch of differential heating/heat retention from different materials.
Okay, okay, y’all are correct! I was being sloppy with my terminology, using “hoarfrost” for any case of when the crystals form into long strings instead of fuzz.