Does quicksand really exist?

Answer

Quicksand does exist, but it is not a separate type of sand or soil. In principle, any sand can become quicksand, as long as it has absorbed enough water. Dry sand derives its bearing capacity from grains of sand stacked on top of each other, which rub against each other and thus offer resistance when a weight rests on it. But if the sand grains are stirred up by a lot of water, they become so loosely stacked that they no longer have contact with each other. Everywhere they are separated from each other by a thin layer of water. Due to a shock, such as from a weak earthquake, but also from a footstep, the sand can then suddenly soften and change into quicksand condition.

Such a thing often happens on the beach, at the high tide line when the water rises. The surface may then appear solid, but underneath it a stick can be pushed deep into the ground without difficulty. You may well know the feeling of stepping onto such a stretch of beach and then feeling the whole layer shake like a pudding.

That is therefore ‘wet quicksand’, the same can also occur when grains of sand are separated from each other by a lot of air, a phenomenon that can often occur in deserts.

But it is still true that the density of quicksand is greater than that of the human body. Therefore, people will float in or on quicksand, and not just sink completely into it. However, once it has ended up in quicksand, it is very difficult to get out. Thus it is not smart to try to pull oneself out by stamping one’s feet; this only results in sinking deeper. However, it is recommended to lie flat so that the pressure can be better distributed.

Sources: TU Delft, University of Twente, Wikipedia