What is a quick sand ? How do you escape from a quick sand ?
Quicksand is actually solid ground that has been liquefied by a saturation of water. 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. It can occur anywhere under the right conditions.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.
Quicksand forms when uprising water reduces the friction
between sand particles, causing the sand to become "quick."
As long as it’s left alone, the structure remains stable. But as soon as it’s disturbed, by stepping on it, the clay changes from a jelly-like consistency to a runny liquid. The effect is the same as stirring a pot of yoghurt. Liquefying the clay makes the quicksand about one million times runnier, and the whole house of cards comes tumbling down, with you inside it.
Very quickly, the sand sinks to the bottom and the water floats to the top. This is where the salt comes in. When there’s enough salt present, as soon as the clay particles liquefy, electrical charges make them begin to stick together to form bigger particles and these also settle with the sand.
The result is a very stodgy layer of sand and clay, which is twice as dense as the original quicksand and packed tightly around the trapped body parts.
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
How do you escape from a quicksand ?
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.
If you step into quicksand, it won't suck you down. However, your movements will cause you to dig yourself deeper into it. 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. Try spreading your arms and legs far apart and leaning over to increase your surface area, which should allow you to float.
Reference taken from: http://science.howstuffworks.com/quicksand1.htm , http://science.howstuffworks.com/quicksand2.htm , http://www.thenakedscientists.com/HTML/articles/article/whatisquicksand-1/
