Amazing Striped Icebergs & Amazing Striped Icebergs & Other Interesting FormationsOther Interesting Formations

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Icebergs: General Information

• An iceberg is a large piece of ice from freshwater that has broken off from a snow-formed glacier or ice shelf and is floating in open water. It may subsequently become frozen into pack ice. Alternatively, it may come to rest on the seabed in shallower water, causing ice scour (also known as ice gouging) or becoming an ice island.

Icebergs Cont.

• Because the density of pure ice is about 920 kg/m³, and that of sea water about 1025 kg/m³, typically only one-tenth of the volume of an iceberg is above water. The shape of the underwater portion can be difficult to judge by looking at the portion above the surface. This has led to the expression "tip of the iceberg", for a problem or difficulty that is only a small manifestation of a larger problem.

Most of the iceberg is under water.

How Big is Big• Though usually confined by winds and

currents to move close to the coast, the largest icebergs recorded have been calved, or broken off, from the Ross Ice Shelf of Antarctica. Iceberg B-15, photographed by satellite in 2000, measured 295 km long and 37 km wide (183-23 mi), with a surface area of 11,000 km² (4,250 mi²). The mass was estimated around three billion tons.

B-15 Comparison• Rhode Island:– Area 1,545 sq. mi.– Length: 48 miles– Width: 37 miles

• B-15:– Surface area 4,250

sq. mi.– Length: 183 miles– Width: 23 miles

• Comparison:– B-15 was almost

three times the size (surface area) of Rhode Island.

Amazing Striped Icebergs• the photographs were taken by Norwegian

sailor Oyvind Tangen from aboard a research vessel. The iceberg photographs were snapped in an area several hundred miles north of the Antarctic. As the message explains, blue stripes are formed as iceberg layers melt and refreeze quickly, while green stripes are created by the freezing of algae-rich sea water. Other colored stripes, such as black, brown and yellow, were created by sediment collected by the ice as it moved down a hillside towards the sea. The icebergs may have taken hundreds or even thousands of years to form.

Other Interesting Glacial Features • Sometimes referred to as “ice wave”

pictures, the pictures that follow show ice formations created by glaciation, melting and refreezing, and other natural forces, over very long periods of time. The "ice wave" photographs are not related to the striped iceberg images and were taken at a different time and place by a different photographer, scientist Tony Travouillon.