Iceberg - this is what? How icebergs are formed

Iceberg - this is a huge ice massif, slippingFrom the continent or island into the waters of the ocean or from the shores. 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 bulk of the iceberg (up to 90%) is hidden beneath the water surface.

Where icebergs are formed

In the northern hemisphere, their birthplace isGreenland, constantly accumulating layers of ice and, from time to time, sending excess into the Atlantic Ocean. Under the influence of currents and winds, ice blocks go south, crossing the sea routes that connect North and South America with Europe. The length of their travels in different seasons is different. In the spring they do not reach up to 50º c. w., and in the autumn can reach and 40º s. w. At this latitude there are transoceanic sea routes.

Iceberg is an ice block that canform off the coast of Antarctica. From this place begins their journey to the 40th 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 dimensions of the icebergs and their number are much higher than those of the northern hemisphere.

Table-shaped icebergs

Having learned what an iceberg is, you can consider themvariety. Table-shaped ice floes are the result of the process of chipping off large areas of ice shelves. Their structure can be very different: from firn to glacier ice. The color characteristic of the iceberg is unstable. Freshly peeled has a white matte shade due to a large proportion of air in the outer layer of compressed snow. Over time, the gas is displaced by drops of water, which makes the iceberg a light blue color.

The table-shaped iceberg is a very massive ice block. One of the largest representatives of this type measured 385 × 111 km. Another record holder had an area of ​​about 7 thousand km². The main number of table-like icebergsorders less than indicated. Their length is about 580 m, the height from the water surface is 28 m. On the surface of some, rivers and lakes with melt water can form.

Pyramidal icebergs

A pyramidal iceberg is the result of icelandslides. They are distinguished by a peak with a sharp end and a considerable height above the surface of the water. The length of the ice blocks of this type is of the order of 130 m, and the height of the above-water part is 54 m. Their color differs from the table-like ones by a soft greenish-bluish hue, but darker icebergs are also fixed. In the thickness of the ice, there are significant inclusions of rocks, sand or silt that hit it while moving around the island or the mainland.

Threat to ships

The most dangerous are the icebergs inNorth Atlantic Ocean. Annually in the ocean, fix up to 18 thousand new ice hulks. They can be seen only from a distance of not more than half a kilometer. This is not enough to have time to turn off or stop the ship to prevent a collision. The peculiarity of these waters is that a thick fog often arises here, which for a long time does not dissipate.

Seamen know the terrible meaning of the word "iceberg". The most dangerous are the old ice floes, which are substantially melted and hardly protrude above the ocean surface. In 1913, the International Ice Patrol was organized. Its employees are in contact with ships and aircraft, gathering information about icebergs and warning of danger. Predicting the movement of the ice hulk is almost impossible. To make them more visible, icebergs are marked with bright paint or a radio beacon operating in automatic mode.