SNOWSTORMS FACE DOWN ON THE LAND. BUT THEY CAN ALSO FACE UP UNDERWATER

The first description of a snowflake as a six-sided, or hexagonal-shaped, ice crystal may have come from Archbishop Magnus of Swe­den in 1555. The word crystal comes from an old Greek word KRYL-LOS, meaning "frost". Further study of a snowflake's shape came later, as the microscope was invented and perfected.

Snow is made of ice crystals, or frozen water vapour. The shape of a snowflake is determined by the supply of water in the air and the temperature of the air. If there is a large supply of water, the snowflake forms rapidly, and as many as fifty crystals will bunch together to make a fern-like shape. Colder air has less moisture, and so, the crys­tals develop more slowly, often in a star shape. In the below-freezing temperature range of 0°C to -40°C, a very strange thing happens. The ice crystal can form around a speck of dust or clay, or metal that happens to be floating in the air!

About one-third of the world gets some kind of snow. Snow even falls in areas on the equator. But many areas of the world have never seen snow and these areas, where you'd expect snow, may be quite far from the equator.

No two snowflakes are alike. Some look like stars, needles, cob umns, plates, triangles, or cones. Others are double-decked with con­necting columns, or spokes.

An important study on snowflakes was done by Wilson Bentley, a Vermont farmer. Over 5,000 of his best snowflake pictures were pub­lished in a book in 1931 called "Snow Crystals".

While Wilson Bentley may have been content to observe snowfalls on land, scientists exploring underwater later went on to make some even more startling and spectacular discoveries — underwater snow­falls! In very deep water, as soon as the temperature goes below 4°C, the water starts expanding. When the water temperature reaches 0°C, that expanding water forms into ice crystals or snowflakes. Keeping that shape, the snowflakes move up in the water, creating the effect of an underwater snowfall, falling UP\ When those snowflakes reach warmer water near the surface, they meet. However, if the surface of the water is frozen, those snowflakes cling to the ice, forming strange but beautiful ice formations.

Heavy snowfalls on land create dangerous situations such as mountain avalanches. Scientists are constantly studying ways to balance snowfalls in some areas by seeding clouds to create snow in other areas.