Know about Quicksand

August 10, 2018

Know about Quicksand

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Quicksand - a terrible hazard we might encounter when we visit in the jungle yet at the same time , it is interesting to know the cause and why it is deadly or not .

There are so many films featuring death by quicksand such as the Tom and Jerry : The Fast and The Furry , Indiana Jones , Krull and etc. The characters in the film may stumble upon in a very large pool of mud that may sink them till death . But what if we fall into the quicksand in real life , will we sink like the other people did in the movies ?.

Quicksand usually consists of sand or clay and salt that’s become waterlogged, often in river deltas. The ground looks solid, but when you step on it the sand begins to liquefy. But then the water and sand separate, leaving a layer of densely packed wet sand which can trap it. The friction between the sand particles is much-reduced, meaning it can’t support your weight anymore and at first you do sink . Some people said that the more you struggle,the further you sink until you drown . The evidence what people know about quicksand are too shallow . After a long year study about the secret behind this hazard ,the scientists specially the geologist proven that quicksand is no longer harm to anyone therefore it is not risky if you know what to do when you are in that situation .

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But first , let me introduce the background about quicksand (which is literally important to know ).

makeitstranger.com

Quicksand is an interesting natural phenomenon -- it is actually solid ground that has been liquefied by a saturation of water. The "quick" refers to how easily the sand shifts when in this semiliquid state.

Quicksand is created when water saturates an area of loose sand and the ordinary sand is agitated. When the water trapped in the batch of sand can't escape, it creates liquefied soil that can no longer support weight. There are two ways in which sand can become agitated enough to create quicksand:

Flowing underground water - The force of the upward water flow opposes the force of gravity, causing the granules of sand to be more buoyant.

Earthquake - The force of the shaking ground can increase the pressure of shallow groundwater, which liquefies sand and silt deposits. The liquefied surface loses strength, causing buildings or other objects on that surface to sink or fall over.

To understand quicksand, you have to understand the process of liquefaction. When soil liquefies, as with quicksand, it loses strength and behaves like a viscous liquid rather than a solid, according to the Utah Geological Survey. Liquefaction can cause buildings to sink significantly during earthquakes.

Places where quicksand is most likely to occur include:

Riverbanks
Beaches
Lake shoreline
Marshes

Furthermore, quicksand is a shear thinning non-Newtonian fluid: when undisturbed, it often appears to be solid ("gel" form), but a minor (less than 1%) change in the stress on the quicksand will cause a sudden decrease in its viscosity("sol" form). After an initial disturbance—such as a person attempting to walk on it—the water and sand in the quicksand separate and dense regions of sand sediment form; it is because of the formation of these high volume fraction regions that the viscosity of the quicksand seems to decrease suddenly.

Quicksand is denser than the human body. People and animals can get stuck in it, but they don’t get sucked down to the bottom—they float on the surface. Our legs are pretty dense, so they may sink, but the torso contains the lungs, and thus is buoyant enough to stay out of trouble.

If you do find yourself stuck in quicksand, the best idea is to lean back so that the weight of your body is distributed over a wider area. Moving won’t cause you to sink. In fact, slow back-and-forth movements can actually let water into the cavity around a trapped limb, loosening the quicksand’s hold. Getting out will take a while, though. Physicists have calculated that the force required to extract your foot from quicksand at a rate of one centimeter per second is roughly equal to the force needed to lift a medium-sized car. One genuine danger is that a person who is immobilized in quicksand could be engulfed and drowned by an incoming tide—quicksands often occur in tidal areas—but even these types of accidents are very rare.