The quicksand phenomenon, quite popular in movie scenes, is actually a specific condition of sandy, water-saturated soil. moving sand
In several cinematographic works, the occurrence of people trapped in quicksand makes one wonder if this phenomenon really exists and if the way in which objects and people are “sucked” by the ground, occurs even as it is presented on the screens. moving sand
Causes of Moving Sand?
For quicksand, known by the English name quicksand, to occur, very specific conditions need to occur. Let’s see:
- First , there must be a water-soaked sandy soil where the grains are suspended in the pores of the soil saturated in an aqueous medium. moving sand
- For this condition to occur, the sands must be soft, thus allowing water to penetrate into the spaces between one grain and another of sand.
- We know that a soil is soaked with water, due to some specific situation such as a flood, a large volume of rain, a high tide or even a tsunami.
- It can happen that this soil is saturated with water (both sandy and clayey), but it is known that over time, grains of sand or clay, which are denser than water, end up sedimentation. That is, the lightest water ends up at the top and the heaviest soil grains settle at the bottom.
So how do grains of sand stay suspended in quicksand?
For the necessary conditions for quicksand to be verified, there must be some type of mechanical vibration in the water-saturated soil. It is this continuous movement of the soaked sand that ensures that the sand grains remain in suspension, only separated by a thin film of water between them. This vibration can originate from: moving sand
- A source of water that rises like groundwater from a mine, spewing water in a continuous flow.
- An earth tremor that causes the ground to vibrate.
- A tsunami that changes the flow of groundwater or surface water.
- Large movements of herds of animals.
The set of indispensable conditions for quicksand to occur, unlike what is presented in hundreds of movies, makes episodes of this phenomenon rare. moving sand
There needs to be a specific relationship between the intensity of the water flow, the diameter, the density and the weight of the grains. It is a requirement for the phenomenon that there is a specific proportion of water in relation to the sand grains and the flow in relation to the physical characteristics of the sand grains.
Quicksand is not specific to any particular region. It can arise anywhere in the world.
However, in places that have experienced earthquakes and tsunamis, it is common for groundwater to rise, creating the specific characteristics for the occurrence of quicksand. It is also possible to find it in swampy regions and near natural springs.
Problems Caused by Shifting Sands
Quicksand can be a big problem if it occurs in a place where some engineering work is intended, such as construction of buildings, roads, ports and the foundation of beams in general.
The most common solution is to divert the water source and drain the soil. moving sand
Agricultural and especially livestock activities cannot be carried out on shifting sand soils. In particular, animal husbandry runs the risk of losing livestock that have been trapped in unstable soil, without being rescued.
People Trapped in Shifting Sands?
As we discovered in this text, the soaked sand must have a type of mechanical vibration to keep the sand grains in suspension.
If someone steps on quicksand and keeps moving, in motion, it will cause even more vibrations in the ground, which will liquefy even more quicksand and possibly that person will sink a bit.
The ideal in the situation is to remain calm and as static as possible. However, the density of unstable soil is always greater than the density of the human body, so if the trapped individual does not continue to make continuous downward movements, there is no risk of being totally absorbed by the quicksand.
The occurrence of animals completely washed away by quicksand, however, can occur, depending on their size and weight. moving sand
Once the animal becomes desperate and moves a lot with the intention of freeing itself, it can dive to the ground. Another situation that can happen is that the animal does not submerge completely, if a human does not seem to release it, it dies of hunger, thirst or becomes food for another animal that will take advantage of its condition. moving sand