Quick Sand

Cecil, quick sand can be a little more serious than you said in your column. I recently went hiking in Death Hollow Utah, named because of a cow that died in quick sand in a steep narrow canyon. This cow blocked the way out for the other cattle. This lead to many dead cows in the canyon. When we were hiking down the canyon we encountered miles of the stuff. Generally it was shallow so we only sank up to our ankles, but several times we stepped into deep pockets and quickly sank. When that happened we dropped to our knees and hands and crawled out. Had we not done that, we could have been in some serious trouble. I don’t know if any of the pockets were deap enough to drown in, but when a person or cow steps in the stuff, you sink like a rock. We encountered so much quick sand because of flash floods that occured almost nightly in the canyon. The flashfloods would add the necessary water to the sand bars on the side of the stream, then when the water receaded, the sand was left above water level, but loaded with water.

Please link to the column so we know what you are responding to.

Presumably referencing: http://www.straightdope.com/classics/a1_158b.html

So which part of Cecil’s answer are you disagreeing with? All he said was that quicksand cannot completely swallow up a person or animal, that you should be able to float in it. That doesn’t mean that it is impossible to drown - it just means that if you keep calm, you will stop sinking with your head still in the air. Though I don’t know how much of your head will remain in the air…

Ok the parts I disagree with:

  1. People and animals don’t float in quicksand, not even for a moment unless you distribute your weight across the quicksand. Thats why I fell to my hands and knees and crawled out of the stuff.

  2. Quicksand is not caused by swirling water.We saw a lot of the stuff that was in pools away from the stream.

  3. There are pools of quicksand deep enough, particularly in the Colorado Plateau that can easily kill cows, or equally stupid people, standing there and waiting to quick sinking is a particularly bad plan.

How do you know people won’t float? Have you ever tried?
Quicksand is denser then water, you float in water, why wouldn’t you float in quicksand?
As a matter of fact, I’ve read answers similar to Cecil’s in guidebooks, but it always made sense to me. Lighter then water-probably lighter then quicksand.

I would imagine part of the danger is not that you don’t float, but that the sand would restrict your motion, and keep you from establishing a good swimming motion. And water-logged clothing makes a good anchor. Ever gone swimming fully dressed? I have as part of a swimming safety class - it makes a difference. So fall in quick sand while fully dressed and get water-logged, then hamper your movement by restricting you in thick goo, and you have a good opportunity to drown.

JOHNPICKETT, I don’t follow your comments about dropping to hands and knees and crawling out. It seems that you were in deep pockets, so to be crawling on the bottom you would have to have been completely submerged. Thus I get the impression you were crawling on top of the quicksand.

As for not being caused by swirling (circulating was the word Cecil used), how do you propose the sand stays afloat in the water, given that sand is more dense than water? Just because the quicksand is not in the main flow of the stream does not make it non-circulating.

Well, no, you don’t float at first. The weight of your body has to exceed the weight of the quicksand before you start floating. If you’re walking in some liquid that only goes up to your knees, then of course your legs plus the rest of your body is going to weigh less than liquid that used to be where your legs are, unless you’re walking in mercury (aka quicksilver :)) or something like that. Try walking in water up to your knees. Do you float? Of course not! But once you get all the way into the water, you will float. And seeing as how cows can drown in water, the fact that they can drown in quicksand doesn’t seem all that surprising.

Ok I see what you folks are talking about floating, yes you can float in quicksand just like you can float on water. But the viscous nature of quicksand makes it important to not wait until you quit sinking to distribute your weight across the quicksand, thus letting you float. The problem is the stuff has suction, if you get up to your hips, you are majorly stuck. Thats how cows die, they sink and then struggle, trip or fall and then drown if the pool is deep enough.

About the suspension, I dont think it is a suspension. I am an accountant, so I am not aware how it works, but I think quicksand works under the same principal that enables a person to fill a glass of water over the rim of a glass without spilling. Quicksand looks just like a sandbar. During our trip we would walk over to a sandbar and have lunch. Sometimes we would walk over to a sandbar and sink like rocks. There is no way to tell the two apart visually, and both can be up to two feet above waterline. Note that either type sandbar would be submerged under the flashfloods that occured at night. If you touch a sandbar made of quicksand, barely jostling it, then the sand slumps and water rushes out of it.