What about the ROUS's?

April 10, 2006 3:21 AM

Quicksand without lots of water. What gives?

I was walking around the Umpqua dunes in western Oregon last week and suddenly fell in! That is, the previously flat ground gave way beneath me and I fell into a newly formed hole which was about waist deep.

There wasn't a lot of water in the sand, which is what I have heard of as quicksand. There was enough moisture that when I climbed out, the vertical sideds of the whole were able to hold themselves up and not just collapse like totally dry sand would.

I figure ther was some air pocket in the sand that I broke through to and fell in. Questions: Is this common? How big a hole can this make? Is there a name for this phenomenon?

posted by aubilenon to science & nature (8 comments total)

Also: Any speculation or actual knowledge on how these conditions form is welcome!
posted by aubilenon at 3:23 AM on April 10, 2006

Wikipedia has a good article on dry quicksand
posted by Psychnic at 4:44 AM on April 10, 2006

Watch Lawrence of Arabia once. Yes they can be in areas of no water. It's basically a depression filled with very lightweight particles that are blown in by the winds. Volcanic dusts and sands in particular are very lightweight and cannot support the weight of a person. So if there is a good sized depression filled with them, you could sink deep.
posted by JJ86 at 6:02 AM on April 10, 2006

In Kesey's Sometimes a Great Notion, Lee falls into what they call a "devil's stovepipe." When blowing sand dunes cover a forest, the trees eventually rot away, leaving a deep, buried hole, perfect for falling into (p. 319).
posted by steef at 7:19 AM on April 10, 2006

Basically a sinkhole, it sounds like. Whatever water source eroded the underlying soil leaving the top intact, but unable to support any load. Regular quicksand is the result of a water source, typically originating from a higher elevation, "floating" a low density soil so that it's unable to support any load. A lot of mining accidents are the result of quick conditions occuring to the mine tailings.
posted by electroboy at 7:36 AM on April 10, 2006

Giant Western Antlion. You're lucky you got away with your life.
posted by Baby_Balrog at 8:02 AM on April 10, 2006

I imagine some variety of air pocket might make just such a trap. Just be glad it wasn't some random pit of Carkoon.
posted by vanoakenfold at 9:26 AM on April 10, 2006

Baby_Balrog wins.
posted by eritain at 11:53 AM on April 10, 2006