Why do icebergs form? What types of icebergs are there? Dimensions of ice mountains

What is an iceberg?

Icebergs are pieces of ice that form on land and float in the sea or lake. Icebergs come in all shapes and sizes, from small ice cubes to chunks of ice the size of a small country. The term "iceberg" generally refers to a piece of ice larger than 5 meters (16 feet) across. Small icebergs, iceberg fragments, can be especially dangerous to ships because they are more difficult to detect. The North Atlantic and the waters surrounding Antarctica are the main habitat for most of the icebergs on Earth.

How do icebergs form and move?

Icebergs form from the ice of glaciers, ice shelves, or break off from an even larger iceberg. Icebergs move with ocean currents, sometimes stop in shallow water or land on the shore.
When the iceberg reaches warm waters, the temperature affects it. On the surface of an iceberg warm air melts snow and ice, small lakes can form on it, which can seep through the iceberg, through cracks in it, thereby expanding them and destroying the iceberg itself. At the same time, warm water acts on the iceberg in its underwater part, gradually melting it and reducing its volume. The underwater part melts faster than the surface part.

Why is it important to study icebergs?

Icebergs pose a hazard to ships passing through the North Atlantic and the waters around Antarctica. After the Titanic tragically sank off Newfoundland in 1912, the United States and twelve other countries created the International Ice Watch to warn ships of the presence of icebergs in the North Atlantic.
The International Ice Survey uses aircraft and radar to track icebergs floating in the paths of major shipping lanes. In the US, the National ICE Center uses satellite data to monitor icebergs off the coast of Antarctica. However, it is only able to track icebergs over 500 square meters(5400 square feet).

Icebergs can also serve as material for scientists to learn more about climate and ocean processes.
By studying the factors that cause icebergs to form, researchers hope to better understand the reasons that lead to the collapse of ice shelves.

Oceanologists are exploring the iceberg, also because of the large volume of cold fresh water they can affect ocean currents and ocean circulation.

Biologists study icebergs to find out how they affect ocean life. How change happens nutrients in the ocean when an iceberg melts. Recent studies have shown that the waters around icebergs are filled with plankton, observed large cluster fish and other marine life.

Photos of icebergs:

An iceberg is a huge mass of ice that slides off a continent or island into the ocean or breaks off from the shore. This word is translated as Their existence was first reliably explained by M. Lomonosov. Due to the fact that approximately 10% less the main part of the iceberg (up to 90%) is hidden below the water surface.

Where do icebergs form?

In the northern hemisphere, their birthplace is Greenland, which constantly accumulates ice and, from time to time, sends the excess into the Atlantic Ocean. Under the influence of currents and winds, ice blocks are sent to south side, crossing sea ​​routes, which connect the Northern and South America with Europe. The length of their journey differs in different seasons. In spring they do not even reach 50º C. las., and in the fall they can reach 40º C. w. Transoceanic sea routes pass at this latitude.

An 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 Panama and However, the dimensions of icebergs and their number here far exceed those in the northern hemisphere.

Table-shaped icebergs

Having learned what an iceberg is, you can consider their varieties. Table-shaped ice floes are the result of the process of calving off large areas of ice shelves. Their structure can be very different: from firn to glacier ice. The color characteristics of an iceberg are not constant. Freshly broken snow has a white matte tint due to the large proportion of air in the outer layer of compressed snow. Over time, the gas is displaced by droplets of water, causing the iceberg to turn light blue.

A table iceberg is a very massive block of ice. One of the largest representatives of this type had dimensions of 385 × 111 km. Another record holder had an area of ​​about 7 thousand km 2. The majority of table-shaped icebergs are orders of magnitude smaller than those indicated. Their length is about 580 m, height from the water surface is 28 m. On the surface of some, rivers and lakes with melt water can form.

Pyramid icebergs

The pyramidal iceberg is the result of ice landslides. They are distinguished by a peak with a sharp end and a significant height above the surface of the water. Length ice blocks This type is about 130 m, and the height of the surface part is 54 m. Their color differs from table-shaped icebergs in a soft greenish-bluish tint, but darker icebergs have also been recorded. The thickness of the ice contains significant inclusions of rocks, sand or silt, which fell into it while moving across the island or mainland.

Threat to seagoing vessels

Icebergs located in the northern part are considered the most dangerous. Atlantic Ocean. Every year, up to 18 thousand new ice bodies are recorded in the ocean. They can only be seen from a distance of no more than half a kilometer. This is not enough time to turn away or stop the ship to prevent a collision. The peculiarity of these waters is that thick fog often occurs here, which for a long time does not dissipate.

Sailors are familiar with the terrible meaning of the word "iceberg". The most dangerous are old ice floes that have melted significantly and barely protrude above the ocean surface. In 1913, the International Ice Patrol was organized. Its employees are in contact with ships and aircraft, collecting information about icebergs and warning of danger. It is almost impossible to predict the movement. To make them more visible, icebergs are marked with bright paint or an automatic radio beacon.

I recently heard that an iceberg broke off from the Pine Island Glacier in West Antarctica. The area of ​​the ice floe is huge and amounts to 300 km² (this is the same as the area of ​​my hometown). I was very interested in this news and decided to learn more about icebergs.

Formation of floating ice

I think that even a child knows that icebergs pose a great danger to sea ​​vessels and animals. It’s not strange, because these ice mountains reach colossal sizes, and their main threat is the part of the ice hidden under water. Icebergs themselves are formed by breaking off glaciers due to the action of wind, currents, tides and water pressure. The largest number of them are carried into the ocean from the glaciers of Antarctica, Greenland, as well as from the northern islands of the Canadian Arctic archipelago. Ocean currents are responsible for the drift of icebergs, so they often move against the wind. If an iceberg floats in the sea for a long time, then through gullies can form in it, due to which the block makes sounds in windy weather. Such ice floes are called singing ones.

Dimensions of ice mountains

The size of the icebergs is impressive. Sailors came up with their own classification, according to which ice blocks are:

• Very large sizes(height more than 75 m, length more than 213 m);
• large sizes (height 46–75 m, length 123–213 m);
• medium size (height 16–45 m, length from 61 to 122 m);
• small sizes (height from 6 to 15 m, length 16–61 m);
• fragments or pieces of icebergs (height up to 5 m, length up to 15 m).

It is noteworthy that these dimensions are established only for the surface part of icebergs. I'm even scared to imagine what is under water.

Sources of “canned” water

Icebergs are usually seen only as a threat. However, in the 21st century, people also benefit from floating blocks. The main goal is to use glacial fragments as a source fresh water. This issue is especially relevant for the arid coasts of Australia and South America, which are close to Antarctica. Iceberg water is immediately drinkable, and its cost will be lower than desalinated water. sea ​​water.

Iceberg (German: Eisberg, "ice mountain")- a huge ice floe that has broken off from the edges of a glacier and is drifting in the ocean or sea.
The nature of icebergs was first correctly explained by the Russian scientist Mikhail Lomonosov.

How does an iceberg form?

Icebergs formed from continental ice Antarctica, can rise above the water to a height of 100 meters. The largest iceberg ever measured had 322 km long And 97 km wide.

Icebergs formed from glaciers Greenland and the Arctic islands, much smaller - the largest of them rise up to 70 m above the water surface.

In just one year, about 26,000 icebergs.

For about a year 370 icebergs They pose a threat to navigation, especially in the Atlantic Ocean, as currents carry them into areas where ships move. Therefore, in the open ocean they are constantly monitored by a special service.

In addition, floating in warm waters The ice mountain is usually shrouded in dense fog and it is possible to see the iceberg too late. But today, sailors are warned of danger by radars (radars), which can “see through the fog.

Iceberg (German Eisberg, “ice mountain”) is a large free-floating piece of ice in the ocean or sea. Typically, icebergs break off from ice shelves. Since the density of ice is 920 kg/m³ and the density of sea water is about 1025 kg/m³, about 90% of the iceberg's volume is under water. Long-term snowfalls and compaction of the snow cover cause the “growth” of the iceberg, turning it into a collection of billions of tiny ice mirrors that reflect light.

Where do icebergs form?

In the northern hemisphere, their birthplace is Greenland, which constantly accumulates ice and, from time to time, sends the excess into the Atlantic Ocean. Under the influence of currents and winds, ice blocks are sent south, crossing the sea routes that connect North and South America with Europe. The length of their journey differs in different seasons. In spring they do not even reach 50º C. las., and in the fall they can reach 40º C. w. Transoceanic sea routes pass at this latitude.

An iceberg is a block of ice that can form off the coast of Antarctica. From this place their journey to the forties latitudes of the Pacific, Atlantic and Indian Oceans begins. These areas are not so popular among sea carriers because their main routes go through the Panama and Suez Canals. However, the dimensions of icebergs and their number here are much greater than those in the northern hemisphere.

Table-shaped icebergs

Having learned what an iceberg is, you can consider their varieties. Table-shaped ice floes are the result of the process of calving off large areas of ice shelves. Their structure can be very different: from firn to glacier ice. The color characteristics of an iceberg are not constant. Freshly broken snow has a white matte tint due to the large proportion of air in the outer layer of compressed snow. Over time, the gas is displaced by droplets of water, causing the iceberg to turn light blue.

A table iceberg is a very massive block of ice. One of the largest representatives of this type had dimensions of 385 × 111 km. Another record holder had an area of ​​about 7 thousand km2. The majority of table-shaped icebergs are orders of magnitude smaller than those indicated. Their length is about 580 m, height from the water surface is 28 m. On the surface of some, rivers and lakes with melt water can form.

Pyramid icebergs

The pyramidal iceberg is the result of ice landslides. They are distinguished by a peak with a sharp end and a significant height above the surface of the water. The length of ice blocks of this type is about 130 m, and the height of the surface part is 54 m. Their color differs from table-shaped ones in a soft greenish-bluish tint, but darker icebergs have also been recorded. The thickness of the ice contains significant inclusions of rocks, sand or silt, which fell into it while moving across the island or mainland.

Threat to seagoing vessels

Icebergs located in the North Atlantic Ocean are considered the most dangerous. Every year, up to 18 thousand new ice bodies are recorded in the ocean. They can only be seen from a distance of no more than half a kilometer. This is not enough time to turn away or stop the ship to prevent a collision. The peculiarity of these waters is that there is often a thick fog that does not dissipate for a long time.

Sailors are familiar with the terrible meaning of the word "iceberg". The most dangerous are old ice floes that have melted significantly and barely protrude above the ocean surface. In 1913, the International Ice Patrol was organized. Its employees are in contact with ships and aircraft, collecting information about icebergs and warning of danger. It is almost impossible to predict the movement of the ice giant. To make them more visible, icebergs are marked with bright paint or an automatic radio beacon.

The shape of an iceberg depends on its origin:

Icebergs from outlet glaciers are table-shaped with a slightly convex upper surface, which is dissected by various types of irregularities and cracks. Characteristic of the Southern Ocean.
Icebergs from cover glaciers are distinguished by the fact that their upper surface is practically never flat. It is slightly inclined, like a pitched roof. Their sizes, compared to other types of icebergs in the Southern Ocean, are the smallest.

Icebergs of ice shelves, as a rule, have significant horizontal dimensions (tens and even hundreds of kilometers). Their average height is 35-50 m. They have a flat horizontal surface, almost strictly vertical and smooth side walls.

In 2000, the largest known ice cap broke off from the Ross Ice Shelf as a result of mechanical ablation. this moment iceberg B-15 with an area of ​​over 11,000 km². In the spring of 2005, its fragment - iceberg B-15A - had a length of more than 115 kilometers and an area of ​​more than 2,500 km² and was still the largest iceberg observed.

The iceberg that broke off the Ross Ice Shelf, named B7B, measures 19 by 8 kilometers (ice area more area Hong Kong) was spotted in early 2010, using satellite imagery from NASA and ESA, at a distance of approximately 1,700 kilometers south of Australia. The original size of this iceberg was about 400 square kilometers. It took iceberg B7B about 10 years to travel this far north. The coordinates of iceberg B7B at the beginning of 2010 are 48°48′ S. w. 107°30′ E. d.HGYAO.

Icebergs, especially table-shaped ones, are characteristic of the south polar region. In the northern subpolar regions, icebergs are more rare; icebergs of relatively small sizes from outlet and cover glaciers predominate among them. From the moment an iceberg of any kind is formed, the process of its destruction continuously occurs, especially actively in the seaward part of the ocean. Numerous forms of icebergs - pyramidal, inclined, round, with arches, rams - arise when they are destroyed. Sloping icebergs are a characteristic initial form of failure, especially of shelf table icebergs. The wave-cut underwater terrace, trying to emerge, lifts one edge of the iceberg. Sloping icebergs are different great height. The average lifespan of icebergs in Antarctic waters is about 2 years (with a volume of iceberg runoff into the ocean of 2.2 thousand km3/year and a total volume of them in the ocean of 4.7 thousand km3).

The color of an iceberg directly depends on the age of the iceberg: only the ice mass that has broken off contains a large number of air in upper layers, therefore has a matte white color. Thanks to the replacement of air with water droplets, the iceberg changes its color to white with a blue tint. Also, don’t be surprised by the pale pink iceberg.