Quicksand - Definition and Overview

This article is about the geological feature. For other meanings, see Quicksand (disambiguation)

Quicksand is loose, water-logged sand which yields easily to weight or pressure. This can occur when water is flowing from a spring beneath the surface, which keeps the sand saturated or supersaturated. The undisturbed sand often is, or appears, solid until some shock or sudden increase in pressure, such as a person stepping on it, causes it to liquify and loose its cohesion.

Quicksand is not as dangerous as depicted in many movies. Because quicksand is denser than the human body, a person will usually float in it. The biggest danger comes from flailing the arms and legs, which literally "digs" that person deeper and can cause him/her to drown.

Quicksand can be found inland (near rivers) as well as in coastal areas. One region notorious for its quicksands is Morecambe Bay, England. As the bay is very broad and shallow, a person trapped by the quicksand would be exposed to the danger of the returning high tide which can come in extremely rapidly.

See also

• dry quicksand
• liquid limit
• plastic limit (soils)
• thixotropy

External links

• Howstuffworks.com - How quicksand works (http://science.howstuffworks.com/quicksand.htm)