Dezian Lamb, age 15, of Keen, N.H., for his question:

WHAT CAUSES A WHIRLPOOL?

A whirlpool is a spinning mass of water that is going around in a circular pattern with much speed and force. A whirlpool may form for a number of reasons. It may form when moving water hits a bank that has a peculiar shape. Ox it may happen when opposing currents meet.

A whirlpool may form because of the action of the wind. Ox perhaps because rocks or tides get in the way of ocean currents.

There are some well known whirlpools. One of the most famous is located in the gorge below the falls of the Niagara River. This whirlpool was caused by the wearing away of a side basin out of the line of the river's course. The Maelstrom, found off the coast of Norway, is a famous whirlpool that is formed by rocks and tines that oppose the current. The Charybdis, found between Sicily and Italy, is caused by winds that act against the tidal currents.

Water draining from a bowl or tub often forms a whirlpool. Under ideal laboratory conditions, a whirlpool spins counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere