Some interesting Info about Quicksand

[abdulhakeem]

What's Quicksand?

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

Quicksand is not a unique type of soil; it is usually just sand or another type of grainy soil. Quicksand is nothing more than a soupy mixture of sand and water -- in essence, the sand is floating on water. It can occur anywhere under the right conditions, according to Denise Dumouchelle, geologist with the United States Geological Survey (USGS).

*picture: quicksand friction (see below)*

Quicksand forms when uprising water reduces the friction between sand particles, causing the sand to become "quick."

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.
Earthquakes - 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.
Vibration tends to enhance the quickness, so what is reasonably solid initially may become soft and then quick, according to Dr. Larry Barron of the New South Wales Geological Survey.

The vibration plus the water barrier reduces the friction between the sand particles and causes the sand to behave like a liquid. 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.

While quicksand can occur in almost any location where water is present, there are certain locations where it's more prevalent. Places where quicksand is most likely to occur include: Riverbanks
Beaches
Lake shorelines
Near underground springs
Marshes The next time you're at the beach, notice the difference in the sand as you stand on different parts of the beach that have varying levels of moisture. If you stand on the driest part of the beach, the sand holds you up just fine. The friction between the sand particles creates a stable surface to stand on.

If you move closer to the water, you'll notice that the sand that is moderately wet is even more tightly packed than the dry sand. A moderate amount of water works to increase the friction between sand particles. This is what allows you to build sand castles.

But beach sand could easily become quicksand if enough water were thrust up through it. If an excessive amount of water flows through the sand, it forces the sand particles apart. This separation of particles causes the ground to loosen, and any mass on the sand will begin to sink through it. In the next section, you will find out how to save yourself if you happen to fall into a pit of quicksand.

http://science.howstuffworks.com/quicksand1.htm

[abdulhakeem]

Quicksand forms when uprising water reduces the friction between sand particles, causing the sand to become "quick."

[abdulhakeem]

How to Escape

If you ever find yourself in a pit of quicksand, don't worry -- it's not going to swallow you whole, and it's not as hard to escape from as you might think.

The human body has a density of 62.4 pounds per cubic foot (1 g/cm3) and is able to float on water. Quicksand is denser than water -- it has a density of about 125 pounds per cubic foot (2 g/cm3) -- which means you can float more easily on quicksand than on water. The key is to not panic. Most people who drown in quicksand, or any liquid for that matter, are usually those who panic and begin flailing their arms and legs.

It may be possible to drown in quicksand if you were to fall in over your head and couldn't get your head back above the surface, although it's rare for quicksand to be that deep. Most likely, if you fall in, you will float to the surface. However, the sand-to-water ratio of quicksand can vary, causing some quicksand to be less buoyant.

"By the same token, if the quicksand were deep, as in up to your waist, it would be very difficult to extract yourself from a dense slurry, not unlike very wet concrete," said Rick Wooten, senior geologist for Engineering Geology and Geohazards for the North Carolina Geological Survey. "The weight of the quicksand would certainly make it difficult to move if you were in above your knees."

Watch animation here (Macromedia Flash 5 Player required) (http://static.howstuffworks.com/flash/quicksand-sinking.swf)

With quicksand, the more you struggle in it the faster you will sink. If you just relax, your body will float in it because your body is less dense than the quicksand.

The worst thing to do is to thrash around in the sand and move your arms and legs through the mixture. You will only succeed in forcing yourself farther down into the liquid sandpit. The best thing to do is to make slow movements and bring yourself to the surface, then just lie back. You'll float to a safe level.

"When someone steps in the quicksand, their weight causes them to sink, just as they would if they stepped in a pond," Dumouchelle said. "If they struggle, they'll tend to sink. But, if they relax and try to lay on their back, they can usually float and paddle to safety."

When you try pulling your leg out of quicksand, you are working against a vacuum left behind by the movement, according to The Worst-Case Scenario Survival Handbook. The authors of the book advise you to move as slowly as possible in order to reduce viscosity. Also, try spreading your arms and legs far apart and leaning over to increase your surface area, which should allow you to float.

While quicksand remains the hackneyed convention of bad adventure movies, there's very little to be afraid of in real life. As long as you keep a cool head in the situation, the worst result will be a shoe full of wet sand.

http://science.howstuffworks.com/quicksand2.htm

[abdulhakeem]

related info:

How to escape Quicksand (http://www.mycamouflage.co.uk/features/survivalQuicksand.asp)

Losing my Quicksand Virginity (Highly recommended) (http://qskerry.stormpages.com/quicksand.htm)

thixotropy (http://www.britannica.com/eb/article?eu=1342)

Mud-trap boy in brush with death (http://www.mucknmire.com/mangrove/articles/news2.htm)

Deadly sands of Morecambe Bay (http://news.bbc.co.uk/1/low/england/lancashire/3465109.stm)

[abdulhakeem]

by the way did you know that in the desert more people are dying by drowning than by thurst?

if it rains in the desert then it is usually a heavy rain - and while walking in the desert it may happen that you hear a loud roaring in a valley and within seconds you may be confronted with a 2 meter water wall or wave that is about to catch you.

besides, it is more likely to find quicksand at beaches, banks/shores and headwater or source regions than in the desert

[abdulhakeem]

How to overcome that sinking feeling in quicksand

Wed Sep 28, 2005

By Patricia Reaney

LONDON (Reuters) - Quicksand is not the bottomless pit portrayed in Hollywood films that sucks in unsuspecting victims and swallows them whole.

It is true the more people struggle, the deeper they will sink into the soupy mixture but its buoyancy makes it impossible to be completely submerged, scientists said on Wednesday.

"Everybody thinks, thanks to Hollywood, that you can drown in quicksand. Basically if you do a simple buoyancy calculation, the Archimedes force, it is immediately evident that you can't drown completely," said Daniel Bonn, of the Van der Waals-Zeeman Institute at the University of Amsterdam in the Netherlands.

Quicksand consists of salt, water, sand and clay. It is the water content that makes quicksand, which is found near estuaries, beaches and rivers, so dangerous.

"If you tread on quicksand, or liquefy it by moving, it goes from something that is almost completely solid to something that is almost completely liquid," Bonn told Reuters.

He and his colleagues showed that Hollywood had got it wrong by measuring the viscosity, the resistance to flow, of quicksand and its sinking ability.

They also calculated the amount of force necessary to get a trapped foot out -- and found it was the equivalent needed to lift a medium-sized car. Their findings are reported in the science journal Nature.

If someone falls into quicksand they begin to sink and the sand packs densely around the feet, forming a type of trap. In films people sinking in quicksand usually grab on to an overhanging tree branch or are pulled out just as they are about to disappear under the mucky surface.

But Bonn and his team said in real life the victim would sink halfway into the quicksand but would not disappear.

The scientists advised people trapped in quicksand not to panic and to wiggle.

"All you have to do to get your foot out is to introduce water into the sand and if you can do that along your leg by wiggling your leg around, that is the best way to get out," Bonn said.

http://today.reuters.co.uk/news/newsArticle.aspx?type=oddlyEnoughNews&storyID=2005-09-28T170954Z_01_YUE861843_RTRIDST_0_OUKOE-UK-QUICKSAND.XML

[forskeNed Life]

:salams

Interesting read. I always thought quicksand was deadly and once a person was in, there was no way out.

:wswrwb:

Nomie