Quicksand: The myth and science behind this natural phenomenon

Quicksand is a natural phenomenon that has captured the popular imagination for centuries, thanks in part to its depiction in movies and books as death traps that ensnare their victims. However, science gives us a more accurate and less frightening view of what quicksand really is, how it forms, and how dangerous it can be.

What is quicksand?

Quicksand is a type of semi-liquid mixture formed by sand particles saturated with water that lose their solid structure when disturbed. Despite its name, quicksand is not exclusively sand; They may be composed of a combination of mud, clay, silt, or any other type of fine sediment.

The peculiar state of quicksand is due to an unstable equilibrium between solid particles and water. When a person or object applies pressure on them, this balance is broken, causing the mixture to lose its ability to support weight, and become an extremely fluid medium. However, quicksand does not “swallow” people in the dramatic sense shown in movies, leading to a widespread myth.

How is quicksand formed?

Quicksand forms in places where fine soil particles are saturated with water, but cannot drain properly due to low permeability of the underlying soil. Generally, they are found in areas such as:

1. Nearby rivers and lakes: Quicksand usually appears on the banks of bodies of water where constant flow keeps the soil saturated.

2. Swamps and marshes: These humid environments with muddy soils provide the perfect conditions for the formation of quicksand.

3. Deserts and coasts: In some cases, underground water reservoirs or tides can create temporary saturated conditions in arid regions or beaches.

When groundwater flows upward or pools on the surface, it can suspend sand particles, creating a mixture that appears stable to the naked eye, but can collapse under enough pressure.

(Photo: Wikimedia Commons)

Is quicksand really dangerous?

Unlike Hollywood depictions, where quicksand “devours” a person completely, the real danger is much less. Quicksand is not deep or dense enough to drag a person completely beneath the surface. The density of the human body is greater than that of quicksand, which makes you float instead of sinking hopelessly.

The real danger of quicksand comes not from being “swallowed,” but from becoming stuck and fatigued, especially if you are in a dangerous location, such as a coast with rising tides or in a remote area. The effort to free oneself can be exhausting, and if not acted upon appropriately, one risks dehydration, hypothermia, or, in extreme circumstances, drowning if the area is flooded.

What to do if you fall into quicksand?

If you find yourself stuck in quicksand, staying calm is crucial. Contrary to what many believe, fighting hard to get out only makes the situation worse by stirring up the mixture and increasing the risk of sinking deeper. Here are some steps to free yourself safely:

1. keep calm: Quicksand only becomes dangerous if you panic and try too hard to free yourself. The key is to move slowly.

2. Relax the body: Instead of trying to fight the mixture, try floating by leaning back to increase the contact surface between your body and the quicksand. This will help you stay on the surface.

3. Move your legs slowly: To release your legs, make small, slow movements, trying to create space around your feet for the water to penetrate and facilitate your release.

4. Use nearby objects: If possible, hold onto a firm object like a branch or rock to help redistribute your weight and make it easier to get out.

The physics behind quicksand

Quicksand behaves like a non-Newtonian fluid, meaning that its viscosity changes depending on the amount of stress or pressure applied. At rest, sand particles are held together by friction, creating a structure that appears solid. However, when pressure is applied, the particles lose contact with each other and become suspended in the water, making the mixture much more fluid.

Once someone falls into quicksand, the weight of the body pushes down, but the water within the mixture does not have enough time to move, creating a sort of partial vacuum that prevents the particles from rearranging quickly. That’s why moving suddenly can cause you to sink more, as it increases the pressure on the mixture.

Demystifying quicksand

Quicksand has been a recurring theme in popular culture, from classic movies to television shows. They are often presented as inescapable death traps, but scientific reality tells us otherwise. Below, we debunk some common myths about quicksand:

· Myth 1: Quicksand sucks you completely underground.
Quicksand is actually less dense than the human body, so you will float before being completely submerged.

· Myth 2: The more you fight, the faster you sink.
While it’s true that sudden movement can make you sink deeper, the process is much slower than what the movies show. Struggling may cause exhaustion, but it won’t make you instantly disappear beneath the surface.

· Myth 3: Quicksand is everywhere.
Although they exist in various natural environments, quicksand is not as common as many think. Its formation depends on very specific soil and water conditions.