Quicksand nostalgia

Hey Matt:

What's the deal with quicksand? As a child I saw movies where people died in the stuff. Cartoon characters sank in it. Yet in all my years of reading the newspaper and hearing of the many weird ways people die, I've never heard of anyone sinking in quicksand. Is there even such a thing as quicksand?

-- Sandy Quik, Sandy Iego, CA

Quicksand lives. It's just not this great deadly sucking hole into which hapless wanderers fall for the enjoyment of moviegoers. Quicksand is almost more a condition than a thing. It's when water from some ground source wells up through silty, sandy clay, breaking the friction bonds between the dirt grains and decreasing their ability to support weight. If the water source is constant, then the quicksand condition remains as a damp, boggy pool. Quicksand can be created during earthquakes, when the ground shaking can make certain kinds of soil act like a liquid. You can even create your own miniquicksand pit at the shoreline, where waves might suspend sand grains in an area enough to make your feet sink into it. So say you step in quicksand, what happens? Depends on how deep the quicksand goes, the ratio of dirt grains to water, and whether you remain calm. Quicksand is likely to be a pretty dense slurry, so even if the area is deeper than you are tall, odds are you will float pretty well. Spread out your arms and legs to distribute your weight around. And move sloooooowly. Panic and thrash and you'll just work yourself down deeper. That's only cool in old movies.