News

Science Time 2 - Whirlpools Sunday, July 27 2008

Those tuning in to Discovery this week to learn about whirlpools and Adam's ride down one, were disappointed to learn there was no show on whirlpools, or anything else for that matter.

So, with the help of Wikipedia and Encyclopedia.com, we'll explore whirlpools today.

A whirlpool is a revolving current in an ocean, river, or lake. It may be caused by the configuration of the shore, irregularities in the bottom of the body of water, the meeting of opposing currents or tides, or the action of the wind upon the water.

As we would have learned in the episode, vortex is the proper term for any whirlpool that has a downdraft.

A good, small scale whirlpool can be seen when a bath or a sink is draining, but these are produced in a very different manner from those in nature. Small whirlpools also appear at the base of many waterfalls or around bridge pillars.

Most whirlpools are not very powerful; the more powerful ones are called maelstroms. The most powerful whirlpools are created in narrow shallow straits with fast flowing water.

Powerful whirlpools have killed unlucky seafarers, but Adam and Jamie showed how much their power tends to be exaggerated. There are virtually no stories of large ships ever being sucked into a whirlpool and the guys proved that it would take a maelstrom stronger than any recorded to do so. Tales like those by Paul the Deacon, Jules Verne and Edgar Allan Poe are entirely fictional.

The closest equivalent might have been the short-lived whirlpool that sucked in a portion of Lake Peigneur in New Iberia, Louisiana after a drilling mishap in 1980. This was not a naturally-occurring whirlpool, but a man-made disaster caused by breaking through the roof of a salt mine. The lake then behaved like a gigantic bathtub being drained, until the mine filled and the water levels equalized. Although some boats and semi trailers were pulled into it in the classic whirlpool stereotype, no human lives were lost.

There are no true whirlpools really dangerous to shipping; the Moskstraumen, near Norway, and Charybdis, near Sicily, are subjects of legend and myth - they are considered the world's most powerful whirlpools, reaching speeds of around 25mph. The Corrievrekin , near Scotland, was feared by the sailors of small boats. The Whirlpool Rapids below Niagara Falls are remarkable for their volume and violence, caused by an irregularity in the Niagara River channel.

But none of these have ever sucked in a ship, or a person, in recorded history, so feel free to jump in a speedboat and grab some skis. Well, maybe not, but at least you know you won't have to be afraid next time you're chugging out to sea from the shores of Norway.