Iceberg is a huge mass of ice that slides from a continent or island into the waters of the ocean or breaks off the coast. This word is translated as "ice mountain". Their existence was first reliably explained by M. Lomonosov. Due to the fact that the density of ice is about 10% less than the density of water, the main part of the iceberg (up to 90%) is hidden below the water surface.
Where icebergs form
In the northern hemisphere, their birthplace is Greenland, constantly accumulating layers of ice and, from time to time, sending the excess to the Atlantic Ocean. Under the influence of currents and winds, ice blocks are sent to the south, crossing the sea routes that connect North and South America with Europe. The length of their journey varies from season to season. In spring, they do not even reach 50º C. sh., and in autumn they can reach 40º s. sh. Transoceanic sea routes pass at this latitude.
Iceberg is a block of ice that can form off the coast of Antarctica. From this place begins their journey to the fortieth latitudes of the Pacific, Atlantic and Indian oceans. These areas are not so in demand among sea carriers, because their main routes go through the Panama and Suez canals. However, the size of icebergs and their number here far exceed those of the northern hemisphere.
Table icebergs
Having learned what an iceberg is, you can consider their varieties. Table-shaped ice floes are the result of the process of breaking off large areas of ice shelves. Their structure can be very different: from firn to glacial ice. The color characteristic of the iceberg is not constant. Freshly chipped has a white matte hue due to the large proportion of air in the outer layer of compressed snow. Over time, the gas is displaced by water droplets, causing the iceberg to turn a light blue color.
Table iceberg is a very massive block of ice. One of the largest representatives of this type measured 385 × 111 km. Another record holder had an area of about 7 thousand km22. The main number of tabular icebergs is orders of magnitude less than indicated. Their length is about 580 m, the height from the water surface is 28 m. Rivers and lakes with melt water can form on the surface of some.
Pyramidal icebergs
Pyramidal iceberg is the result of ice landslides. They are distinguished by a peak with a sharp end and a significant height above the water surface. The length of ice blocks of this type is about 130 m, and the height of the above-water part is 54 m. Their color differs from table-like ones by a soft greenish-bluish tint, however, darker icebergs have also been recorded. There are significant inclusions of rocks, sand or silt in the ice column, whichgot into it while moving around the island or mainland.
Maritime threat
The most dangerous are icebergs located in the North Atlantic Ocean. Up to 18 thousand new ice giants are recorded in the ocean every year. You can only see them from a distance of no more than half a kilometer. This is not enough time to turn away or stop the ship to avoid a collision. The peculiarity of these waters is that thick fog often appears here, which does not dissipate for a long time.
Sailors are familiar with the terrible meaning of the word "iceberg". The most dangerous are the old ice floes, which have melted significantly and almost do not protrude above the ocean surface. In 1913, the International Ice Patrol was organized. Its employees are in touch with ships and aircraft, collecting information about icebergs and warning of danger. Predicting the movement of the ice giant is almost impossible. To make them more noticeable, icebergs are marked with bright paint or with an automatic radio beacon.
