A human or animal does not sink entirely into quicksand due to the higher density of the fluid. However, a person does not drown in quicksand. If animals or people stand on it, they sink into it.
It has the characteristic of thixotropy: it looks solid, but when pressure is applied it liquifies (acts like a liquid). Don’t fear the quicksand, just respect it.Quicksand is a mixture of water and sand or silt. Most importantly, don’t hike alone and be aware of hazards in silty wet places. Many people can extract themselves relatively easily provided they can get leverage and move their legs/feet slowly and pull out. Don’t panic and move slowly and deliberately towards safe ground. This will loosen the material around your limbs. Instead, move a little back and forth to create a space for water to move into. When you try pulling your leg out of the semi-liquid, you are working against a vacuum left behind. Stopping can cause the viscosity of the material to increase (like when you stop stirring the corn starch). Selectively increasing the stress is the key to escape. If you discover you are rapidly sinking up to your waist, toss off any extra backpacks and attempt to redistribute your weight by lying back.
The so-called Black Grounds along the land’s edge consists of jelly-like mud. Accessible only during low tide, the trail has claimed some who have gotten stuck in the quicksand and could not escape before the tide returned “faster than a man could run”. The Broomway path in the UK is a well-known hazard in Southend-on-Sea, England along the edge of the aptly named Foulness Island. As with other areas, it was difficult to tell what ground was unstable until you stepped in it.
In 2014, a 78-year old woman who frequently hiked alone in Arches National Park, Washington without issue became stuck in quicksand for 14 hours before rescuers helped free her. A similar event in 2012 in Geelong, Australia required the horse to be sedated to get him out before the tide came in. In 2019, two horses had to be rescued from Merthyr Mawr beach in Glamorgan, South Wales after they sunk into quicksand.
We were assured that quicksand is real but you can’t sink in more than halfway. The results of the experiment made news headlines. In 2005, researchers published in Nature how they simulated natural quicksand from a location in Iran using sand, clay, and saltwater. You are almost guaranteed to lose your shoes during a quicksand escape if they aren’t laced tight. The high viscosity of the saturated sand creates resistance and suction. It is always more dense than water alone. Quicksand doesn’t suck you down, but you sink into as you would in any liquid. No scary creatures live in the sand to consume you. As mentioned, quicksand pits are not bottomless. “Quick” refers to how easily the sand changes character from solid to liquid. “Quick” suggests the sand comes to life but instead it gives way. Kids experiencing quicksand at Mont-Saint-Michel, an island in Normandy, France. Therefore, thrashing around will indeed cause you to sink and become more engulfed. The higher the stress applied to the material, the more liquid it becomes. Is this a liquid or a solid? It’s a thixotropic solution.) (Add water to corn starch while slowly stirring to make it just liquid. Clay deposits can exhibit thixotropic behavior and lose their shear strength suddenly due to vibration. Silty areas can more easily liquify than sand. Natural areas of quicksand can be found where there is upward flowing water, like at the outflow of spring, or near rivers or on beaches where water is present just below the surface. Buildings constructed on wet ground can collapse during the shaking when the shear strength is suddenly reduced and the particles flow past each other. Vibration, such as from an earthquake, can trigger a complex process called liquefaction. The sand suddenly loses stability and collapses. The sand may look stable and can hold light weight but a force such as a foot bearing down disrupts the balance. Additional water reduces friction, the particles separate and the mixture flows. A moderate amount of water and sand results in packed grains that are held fairly tightly together and can sustain weight. Think about how you moisten sand at the beach to build up a sand castle. “Lighning sand” from the The Princess Bride (1987) Sediment + water