How does quicksand suck its victims down

A.� It doesn't suck, rather the victim sinks, as they would do in any other liquid. The myth about quicksand sucking people in probably springs from the fact that it's very thick, providing suction, especially if the quicksand meets resistance from the victim's boots or flat-soled shoes. The quicksand's density can sometimes create vacuums if the victims struggles - adding to the suction myth.

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In fact, since it's denser than water it's actually easier to float in quicksand than it is in water, especially if you fill your lungs with air if you do fall in.

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Q.� What is quicksand

A.� It's basically a mixture of sand and water. Water percolates up through it, creating a drag force on the sand grains. If the water is moving fast enough then the upward force exceeds the downward pull of gravity, suspending the sand in it and it behaves like a liquid -�a process known as 'fluidisation'.

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As a thin film of water surrounds each grain, the sand particles lose contact and friction. Toss a rock onto what looks like solid sand, and it'll disappear just as if you'd thrown it into water.

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Q.� Why is the sand describe as 'quick'

A.� 'Quickness' is a scientific terms used to describe the way that water, when flowing through sand, can lift and separate its small grains.

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Q.� Is quicksand hard to spot

A.� It can be, because the cushion of water that is holding the sand grains slightly apart is invisible. So what appears to be a normal solid surface of sand actually in fact a liquid.

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Q.� Where can I find quicksand

A.� Quicksand can be found anywhere where water and sand live side by side. Hilly areas with limestone caves containing underground springs are particularly prone to quicksand. Quicksand can also be hidden under leaves and dried out crusts of mud.

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Q.� What should I do if I fall into quicksand

A.� The main thing is don't struggle. Slowly get rid of anything heavy that you're wearing and work yourself into a floating position on your back.

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by Lisa Cardy