quicksand

Factual Questions
1

I know what it is. I even know how to save myself if I should fall in. But I’ve never seen it outside of the movies. Is it a common phenomenon?

Maybe it’s a regional thing. I’ve lived most of my life in relatively dry, mountainous areas. But I’ve visited a few swamps, marshes, bogs and sloughs and never come across it.

Is it simply a convenient plot device? It seems like you can’t go ten steps in most jungle movies without falling into it (and the otherwise ubiquitous vines are always just out of reach). Mel Brooks found some out in the desert in “Blazing Saddles” and almost lost a perfectly good handcart.

Do any of the Teeming Millions have any personal experience with it?

2

Hi pluto

This was covered by Cecil himself.

Is there really such a thing as quicksand?

3

Thanks, Trion. I should have checked there first.

But even The Great One didn’t answer the part I was most curious about. How common is it? As I said, I’ve never come across it and I’ve never met anyone who has. I’m looking for someone who has at least seen it, or maybe thrown a rock into it to see what would happen.

Or I need a very gullible person to volunteer for an experiment.

4

There is/was something like qs under the buildings in the Marina district of San Francisco. Caused much havoc during the last big earthquake.
Also, when I was a kid in Bakersfield, there was sometimes qs in the Kern River. Mostly at a place called “The Wiers”, where irrigation canals drained from the river. It wasn’t very deep, and changed location a lot. Us kids liked to play in it.
Peace,
mangeorge

5

The Encyclopædia Britannica article has information about where quicksand is found, but not about how common it is.

6

If you could find a spring where there was actual upward flow but was choked with sand particles, you would find quick sand. Maybe that is why the above posts mention it is found near rivers. Most springs flow clear unless continually covered over by river sediment. The problem in the Marina District was quicksand but is referred to in engineering circles as liquifaction. Loosly deposited sand forms an open structure with lots of voids. These voids are filled with water (saturated). During an earthquake, the loose sand structure collapses into a denser, more compact structure. With less voids, the water previously in the pore space between the now compacted sand particles flows with quick sand like results (sand and mud boils, sinking buildings and people etc.)

To see this in minature, next time you are at the beach or the edge of a river, find some damp sand near the water. With the ball of your foot lightly but rapidly vibrate the sand. This will collapse the loose sand and you will see water come to the surface in a quick condition.