How is quicksand formed in the desert?

Reasons for the formation of quicksand: The reason is that soft sediments filled with water are stimulated by external forces. When water is surrounded by sand piles and cannot be drained, water and sand form unbearable liquid soil. Quicksand can be formed by still water, upwelling water (such as groundwater) or earthquakes. In the case of upwelling, the momentum of water counteracts gravity, resulting in suspended sediment particles.

Quicksand refers to the phenomenon that saturated loose sand, especially silty sand and fine sand, liquefies and flows under the action of earthquake force or hydrodynamic force. True quicksand is a kind of hydrocolloid substance in sand, which is difficult to discharge and eliminate. Pseudo-quicksand is a kind of sand which contains no hydrocolloid substance and is easy to drain. After draining, its fluidity disappears.

When an earthquake occurs, vibration will increase the water pressure of surface water, leading to liquefaction of sand and gravel and sediment accumulation. In both cases, the liquefied ground loses its bearing capacity, which leads to the ground collapse or the buildings on the ground tilt. Water-bearing sand may look dry and solid, but if the pressure changes or is suddenly shaken, the water between the sand grains will penetrate above the sand layer, forcing the sand grains to separate and expanding the sand pile. At this time, a layer of water cushion will be formed between the sand grains, forming quicksand. An object trapped in quicksand will sink until it reaches a depth equivalent to the specific gravity of quicksand, and it will be suspended at that depth due to buoyancy.

Extended data:

Once the surface of quicksand is disturbed, it will "liquefy"

Bourne of the University of Amsterdam in the Netherlands met a local shepherd while on vacation in Iran. Pointing to quicksand, he told Bowen that once a camel sank in the village and disappeared immediately. Bern was skeptical about this and immediately studied it after returning to China. He carefully watched and analyzed dozens of movies describing the scene of quicksand eating people, and found that the descriptions of quicksand in these movies were simply full of mistakes. Later, Bourne mixed fine sand, clay and salt water in the laboratory and reconstructed a miniature indoor quicksand model for research.

Baidu Encyclopedia-quicksand (geographical term)

Baidu encyclopedia-quicksand phenomenon