Icebergs are the most common in the Atlantic Ocean. Unique works of nature

Scientists have calculated that the ice cover, the largest island on Earth, is updated in about 6 thousand years. This means that a significant part of the Greenland glaciers during this time turns into icebergs that "wander" across the North Atlantic. The same process is constantly happening in Antarctica, where the largest glaciers on Earth are located.

Having reached the edge of the land, the glacier either hangs over the water surface in the form of a cornice or peak, or continues to move along the shelf (continental shallows). From time to time, huge blocks - icebergs - break off from the ice massif with a frantic roar. (“Iceberg” is translated from Dutch as “ice mountain”) At the same time, waves are formed that are very dangerous for ships that are nearby.

Some icebergs, in size, can compete not only with mountains, but also with entire mountain ranges. The largest iceberg ever discovered, which fell off the Ross Ice Shelf in Antarctica in 2000, had a surface area of about 10,000 km 2 and an altitude of more than 100 meters. Five years later, its fragment was more than 115 kilometers long and more than 2500 km 2 in area. According to scientists, such "ice mountains" are able to influence ocean currents and weather conditions, especially since sea currents carry icebergs many thousands of kilometers from their places of "birth". This is how the long-term wanderings of the icy mountains begin.

The density of sea water is about 1025 kg / m 3, and the density of ice is 920 kg / m 3. Therefore, only the tip, a tenth of the volume of the iceberg rises above the water, and the remaining ten ninths of the volume are under water and are invisible to the observer from the ship. This "hidden" part of the floating ice rock poses the most serious danger.

In the history of navigation, there are many cases of collision of ships with wandering giants. So, on February 20, 1856, near the island of Newfoundland, after a collision with an iceberg, an American sailing ship crashed. The entire team died - 135 people. And in 1928, the Danish pyatishoglovy longboat "Copenhagen" mysteriously disappeared. The ship was sailing from Montevideo to Australia and there were 59 people on board. In the latitudes where the launch route passed, giant Antarctic icebergs drifted. In 1943, in the North Atlantic, the British tanker Svend Foyn, along with her entire crew, sank into an iceberg. But the most famous of these disasters occurred on April 1, 1912. The newly built largest ocean liner Titanic, which launched its first transatlantic voyage, collided with a giant iceberg and sank, despite the fact that it was considered absolutely reliable and unsinkable. At the same time, out of 2208 people of passengers and crew, only 706 were saved.

With the advent of radar equipment on ships, the risk of such collisions has decreased. However, even the most modern devices sometimes fail. In November 2007, off the coast of the South Shetland Islands, the Explorer cruise ship crashed into an icy mountain and received a hole. Fortunately, all passengers managed to be evacuated and placed on another ship even before the liner disappeared under water.

An extraordinary feature of icebergs is their ability to "tumble". In warm waters, the ice melts much faster, and the position of the center of mass of the ice mountain changes, and from time to time the icebergs suddenly turn over. There is a known case when, as a result of such a “tumble”, a passenger ship, which was near a large iceberg, was picked up by it during capsizing and ended up on the ice surface. However, the new position of the iceberg turned out to be unstable, and in a short time he made a “somersault” in the opposite direction, and the ship was again afloat without receiving serious damage. It is interesting that the iceberg, which recently “turned over”, differs from its counterparts in the dark blue color of the ice.

Most of the ice mountains are table icebergs. A distinctive feature of these icebergs is a flat surface, like a table. Under the influence of sea waves and sunlight, the shape of icebergs changes over time. The "older" the ice mountain, the more inventive its appearance. Some of them, having traveled for several years in the waters of the North Atlantic or in the south of the Indian and Pacific Oceans, become like giant snow-white swans or rocky islands with wide valleys, sharp cliffs and picturesque bays. Many icebergs exist so long that they form colonies of seabirds - skuas, gulls, penguins, and seals.

The clusters of icebergs found at the Antarctic ice barrier usually look like ice cities, created by an architect with indomitable imagination and unlimited possibilities. Illuminated by the sun, they shimmer with all the colors of the purest fresh ice - from dazzling white to a deep blue-violet tone.

At the end of the 20th century, the European Space Agency and NASA created satellite systems that monitor the movement of ice traveling mountains in the oceans of the planet, the movement of ice sheets and the formation of new icebergs around the clock. In December 2009, the Yegmizat satellite discovered a huge iceberg off the coast. An ice block measuring 19 by 8 kilometers (larger than the area of Hong Kong) that fell away from the Ross Ice Shelf took 10 years to cover such a distance.

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“The ship was sailing 270 meters from the ice shelf, when a huge block weighing about a million tons broke off from its edge with a loud crack. pieces of it kept breaking off, and it became smaller and smaller. When the roar subsided, in the midst of numerous white fragments there remained a beautiful blue mountain, like the core of a flower among sleeping petals. The well-known Australian polar explorer, the conqueror of the South Magnetic Pole and the southernmost volcano of the Earth - Erebus - Douglas Mawson describes the picture of the birth of an iceberg in such a poetic and at the same time documentary way.

The formidable floating ice mountains are huge masses of ice that have broken off from glaciers sliding into the sea or broken off, as Mawson describes, from the edges of giant ice sheets covering Antarctica and Greenland. the surface of the sea comes at this time into great excitement, and the waves formed are so great that they overturn the boats and throw small fishing vessels far away.

ICEBERGS, large blocks of fresh ice that have broken off from glaciers descending into the sea or a near-glacial lake (ordinary floating ice and pack ice are formed when the surface of the sea freezes). The main sources of icebergs are the fjord glaciers of Greenland and the ice shelves of Antarctica. The length of Antarctic icebergs sometimes reaches 80 km. Some icebergs rise above the water surface by more than 60 m. Depending on the shape of the icebergs, their underwater part is 7-9 times larger than the surface part. The drift direction of icebergs depends mainly on ocean currents, so icebergs often move against the wind.

The word "iceberg" is translated into Russian as "ice mountain" This is no exaggeration, since icebergs really reach enormous sizes. In the ocean there were ice giants tens and even hundreds of kilometers long and hundreds of meters high. Back in 1854-1864, scientists for ten years followed the movement of a giant iceberg, which had a length of 120 kilometers and a height of 90 meters. And in 1927, an ice island was noticed from a Norwegian whaling ship, reaching a length of 170 kilometers. But the largest iceberg was discovered in Antarctic waters in 1956. It was 385 kilometers long and 111 kilometers wide. In terms of area, it was equal to almost half of a country like Slovenia, or three Luxembourg!

And the highest iceberg was met in 1904 off the Falkland Islands in the South Atlantic. The height of the peak of this ice mountain was 450 meters!

Due to the fact that ice is lighter than water, and also due to air bubbles in ice crystals, icebergs have good buoyancy. At the same time, only one eighth of the ice mountain is visible on the sea surface, the rest of its mass is under water. Therefore, icebergs are driven by the force of sea currents, not air currents, and often swim against the wind and even through ice fields up to two meters thick. Woe to a ship frozen in such an ice field - an iceberg will crush it like a matchbox!

Antarctic icebergs rarely move far north into the Indian Ocean and the South Pacific, where the main shipping routes pass, although they have been encountered 160 km south of Australia. In the South Atlantic, icebergs drift with the Falkland Current from Cape Horn to the Cape of Good Hope. The North Pacific Ocean is separated from the Arctic Ocean (with the exception of the narrow Bering Strait) and is free of icebergs. 10-15 thousand icebergs annually break off from the West Greenland glaciers, many of them come from eastern Greenland and from the northeast Arctic coast of Canada. The Labrador Current carries these icebergs south along Newfoundland, and then the Gulf Stream carries them across the Atlantic in a north-northeast direction. From April to August, icebergs are abundant on the busy North Atlantic shipping lanes and can be observed throughout the year in areas north of 43°N. Sometimes in the south they came across up to the latitude of the Azores.

In clear weather, due to their shiny surface, icebergs are visible from afar. At night, breakers form a warning white line around their base. In fog, they are poorly distinguishable at a distance of more than 90 m, and before the invention of radar, they were detected using a ship's siren, the sound of which was reflected from their surface. The sinking of the first-class liner Titanic in 1912 was the result of carelessness, and this was the reason for the very strict rules of navigational safety still in force. On a moonless night between 14 and 15 April, the ship continued to move at a speed of 22 knots despite radio warnings of floating ice in the area. It collided with an iceberg 40 seconds after it was spotted and sank 2 hours and 40 minutes later, with the loss of 1,513 lives.

The "parents" of icebergs are the vast glaciers of Greenland, Svalbard, Franz Josef Land and the island of Canada. 18,000 icebergs "start" from there every year.

The process of iceberg birth is slow. The area of the glacier slowly slides onto the water, driven by bad weather and washed away by oncoming waves. Then the breakaway part of the glacier crashes into the water. The air bubbles in the iceberg, and also due to the fact that ice is lighter than water, the iceberg has good buoyancy.

The process of the birth of an iceberg is accompanied by very interesting and unlike sounds

Large lakes are often found on the surface of flat icebergs, sometimes up to twenty kilometers in diameter. On such ice islands there are also rivers and streams flowing into the sea with beautiful waterfalls. One of these rivers reached a length of four kilometers and a depth of twelve meters.

Sea water washes deep tunnels and caves in icebergs. Sometimes, however, the caves go to the ice mountain "inherited" from the glacier that gave birth to it. The cracks formed during the movement of ice tongues along the mountain slopes can then close at the top if the glacier enters the plain, and then long subglacial cavities remain inside it, which eventually approach the coast and go along with the ice block containing them on a long voyage.

The interior of these sub-glacial, or, more precisely, "intra-ice" caves is a spectacle of amazing beauty. Here is what one of the participants of the Soviet Antarctic expedition of 1965 says about this:

"A round corridor about three meters high went into the depths of the ice mountain. The wavy walls were made of smooth, precisely polished ice. An unusual bluish-blue light passed through the entire ice massif, gently flowing, shimmering in the ice walls. Reflections of light that penetrated the ice played on the icicles. into the entrance hole. The fantastic blue color of the walls, the play of light, the steam escaping from the mouth in clubs, tuned in to a solemn mood. We involuntarily spoke in a whisper and slowly walked along the corridor ... The passages branching in all directions pierced the iceberg, and the most amazing thing about them was huge ice crystals that hung from the ceiling and completely covered the walls, it was a hoarfrost, similar to that which can be seen on the windows on a frosty day, only magnified many times over.

Ice needles, like flowers of the most bizarre forms, sparkled and sparkled in the blue diffused light. It was terrible not only to move, but also to breathe among this unusually fragile and indescribable beauty. We lit the matches, and they suddenly burst into a bright red flame. Sure, the fire from the lit match seemed so bright in contrast to the bluish lighting of the cave, but that didn't make it any less beautiful."

Once, our sailors met even a “singing” iceberg off the coast of Antarctica. Water washed through holes in it, in which the wind arranged rather melodic “concerts”, as if playing on a huge flute.

Sometimes icebergs resemble the outlines of medieval castles or watchtowers. They are called pyramidal. But more often there are flat, so-called table icebergs. Sometimes there are also colored floating islands: black, green or yellow. It is believed that the reason for the unusual color of the icebergs is the volcanic dust covering them.

Interestingly, floating ice mountains can be found not only in the seas and oceans. In the Tien Shan, at the foot of the majestic Khan Tengri peak, there is a glacial lake called Merzbacher. When a scientific expedition first came to the lake in the 1920s, its members were surprised to see, off the coast of Greenland, that large icebergs were floating on the lake, apparently detached from the Inylchek glacier that formed the lake. One of the scientists of the expedition described the picture he saw as follows:

"Icebergs, sparkling in the rays of the southern sun, floated in the water. Ice towers and castles, covered with snow and burning in the sun with myriads of snow crystals, translucent grottoes on the surface of icebergs, hanging icicles playing with all the colors of the rainbow - all this created a fabulous impression."

Icebergs have always posed a serious threat to ships. Especially dangerous in this regard are Greenland icebergs, which are driven by winds and currents to the south, to the shores of North America, where busy shipping lanes lie. Moreover, if in March the ice mountains reach only the island of Newfoundland, after which they melt and disappear, then in October they sometimes reach the latitude of New York, creating a dangerous obstacle on the way of transoceanic liners traveling from Europe to the USA and back.

The danger is aggravated by the fact that in this area the cold Labrador Current meets the warm waters of the Gulf Stream, which causes thick and prolonged fogs. Meanwhile, icebergs up to 20-30 meters high (the majority of them in the North Atlantic), even on a clear night, are distinguishable only from a distance of 500-600 meters, which does not allow the captain, even if he ordered "Full back!", to avoid a collision with a fatal obstacle .

The greatest maritime disaster of the 20th century forced maritime powers to take action to avoid similar tragedies in the future. As a result, in 1913 the International Ice Patrol in the North Atlantic was created. Patrol boats and aircraft monitor the appearance of icebergs and warn passing ships by radio. During the year, the patrol reveals up to four hundred dangerous ice mountains, on which special radio beacons are installed or their surface is painted with bright orange paint.

However, even patrolling does not give a full guarantee of avoiding collisions. So, already today, in 1959, the Danish ship "Hans Hedhof" crashed into an iceberg in the fog and sank with all passengers and crew. 95 people died. The danger is also approaching at close range to the floating ice mountain. Icebergs melting from below gradually lose their stability and can suddenly roll over, destroying an inadvertently approaching ship.

The capsizing of the iceberg was observed from the ship "Ob" in the Davis Sea, and eyewitnesses describe this event as follows:

“In calm weather, there was a strong roar, comparable in strength to an artillery salvo. Those on deck saw at a distance of no more than one kilometer a slowly overturning pyramidal iceberg about forty meters high. Huge blocks of ice broke off from its surface and fell into the water with a roar. When the surface part of the iceberg sank noisily into the water, a rather large swell began to diverge from it, causing the ship to roll. On the surface of the sea, among the wreckage, a new hilly and uneven top of the iceberg slowly swayed.

Many large icebergs live in the sea for several years. In the Antarctic, they are often inhabited by large colonies of penguins and other seabirds. Some even make nests there. The durability of icebergs gave people the idea to try using them to supply fresh water to arid countries in Africa and Arabia. Thus, a project arose to tow large icebergs by special ships to the shores of the Persian Gulf in order to use the water formed during their melting for water supply and irrigation of fields. It has been calculated that the amount of water generated by the melting of one medium-sized iceberg is equal to the annual flow of a large river. Time will tell how realistic the implementation of such a project will be.

During stormy weather, ships sailing off the coast of Antarctica often use icebergs to protect themselves from raging waves, sheltering on their leeward side from the storm. And pilots of Antarctic expeditions sometimes choose their flat surface as a landing strip. Of course, at the same time, one must always remember the insidious nature of the ice islands and be on the alert. After all, the behavior of icebergs is unpredictable and at any moment you can expect a surprise from it.

Here's how an iceberg once "joked" with the Canadian steamer "Porscia". It happened in 1893. The Portia was on a cruise with a large group of tourists on board, when suddenly a floating ice mountain appeared ahead of them. The passengers asked the captain to come closer - the iceberg was too beautiful, they wanted to get a better look at it and take a close-up photograph. But as soon as the ship sailed close to the iceberg and the tourists snapped their cameras, something incomprehensible happened. An unknown force began to lift the Portia out of the water. In a few seconds, the ship was already above the surface of the sea on a huge iceberg ledge, which had previously been under water. Apparently, the ice mountain was swaying in the water, and as the steamer approached it, the slope allowed the ship to pass over the underwater cornice. Then the iceberg began to roll in the other direction and lifted the steamer into the air. Fortunately, this didn't last long. When the iceberg leaned back again, the ship was in the water without even receiving minor damage. At full speed, the captain steered the ship away, away from the ice trap. The passengers did not even want to think about what could happen if the iceberg turned over.

I must say that, despite the well-deserved gloomy fame, icebergs make a striking impression on the traveler who sees them for the first time with their kind of unearthly, fabulously romantic beauty. Their forms can be the most bizarre and unusual: either it is a giant snow-white swan or a hilly island with wide valleys, in which only a cozy village is missing, or an island with high mountains, gorges, waterfalls and sheer cliffs that form beautiful, picturesque bays. There are icebergs that look like a ship with wind-blown sails, a column on a beautiful pedestal, a pyramid, an ancient city with walls, turrets and drawbridges...

And those who happened to see their fantastic outlines on the dark surface of the sea, reminiscent of floating enchanted castles, white-blue, blue-green or pink at sunset, will never forget this majestic and beautiful sight.

Even a relatively small ice mountain 150 m thick, 2 km long and half a kilometer wide contains almost 150 million tons of fresh water, which is completely clean, devoid of impurities and pollutants.

Of course, these projects are not easy to implement. Powerful tugs and reliable cables are needed. It is important to lay the most advantageous path for the iceberg in the ocean in order to use favorable currents and winds, and make the iceberg melt more slowly.

Iceberg is a majestic natural work of art. Huge ice sculptures up to 100 meters high, floating in the sea, are a formidable and at the same time bewitching sight. They make you tremble and revere the powerful forces of nature.

Unique works of nature

An iceberg is a natural phenomenon, the splendor and majesty of which can hardly be depicted on film, its incredible ice power can only be felt in person. What is it? No two icebergs are the same, shapes and sizes are very rare. The very fact of their appearance and formation is interesting.

Birth of the Frost Giants

An iceberg is a formation that consists of highly compacted snow that fell on the Greenland ice cap several thousand years ago, if not more. Due to constant change and movement, thousands of icebergs appear every year, which are mainly formed in the sea from glaciers in the central and northwestern region of Greenland, as well as on its eastern coast.

Size matters

Iceberg is a natural phenomenon that can appear in a variety of shapes, sizes and configurations. The tallest of them rise above the surface of the ocean at a height corresponding to a 15-story building, and the smallest are similar in size to a small hut. It is not uncommon for entire palaces of icebergs to gently drift under the influence of currents in arctic waters.

This is just the tip of the iceberg

No matter how big the iceberg may seem, this is just its top, the remaining 7/8 parts of its massif are at sea depth. Antarctica and Greenland, where all the ice sheets in the world are located, are the main sources of this natural phenomenon in the world. One eighth of the iceberg is visible above the water, the other is located below the surface of the water. This is where the phrase “tip of the iceberg” came from, meaning only part of an idea or problem.

Why are icebergs blue?

Some glaciers and icebergs have a bluish tinge. The chemical bond of oxygen and hydrogen in water absorbs light in the red end of the visible light spectrum. Blue glaciers and icebergs are blue for the same reason that the sky is blue, which is due to atmospheric scattering of light.

Large chunks of ice

An iceberg is not just a large piece of ice that has broken away from a glacier. It contains frozen fresh water. Most of them in the Northern Hemisphere come off the glaciers in Greenland. They sometimes drift south with currents into the North Atlantic. In the Southern Hemisphere, almost all icebergs come from Antarctica.

Some of them are small, just floating sea ice that extends no more than 5 meters above the ocean. Icebergs can also be huge, sometimes larger than some islands such as Sicily, the largest island in the Mediterranean.

dangerous ice

There are many different types of icebergs. For example, shaggy ice is a set of floating ice and icebergs no longer than 2 meters. Underwater icebergs are especially dangerous. Sharp hidden ice can easily make a hole in the bottom of a ship. A particularly treacherous part of the North Atlantic has become known as Iceberg Alley due to the large number of underwater ice formations. This place is located 250 miles east and southeast of Newfoundland (Canada).

In 1912, the Titanic, a large British ocean liner, collided with an ice mountain on its way to New York and sank in Iceberg Alley. More than 1500 people died. Shortly after the Titanic sank, the International Ice Patrol was set up to track icebergs and warn ships. This patrol continues to operate today.

Where do icebergs go

Iceberg - what is it? How long can it exist? Where is he sailing? Ice masses that are torn from glaciers and drift into warmer waters eventually melt. Scientists estimate the lifespan of an iceberg, from the first snowfall on the glacier to the final melt in the ocean, at around 3,000 years. For obvious reasons, it is very difficult to accurately determine the lifetime of an iceberg. The movement of the largest ice floating formations is monitored by satellites.

Shapes and sizes

Smaller icebergs may originate from glaciers or ice shelves, or may also be the result of a large iceberg breaking apart. They are also completely different in shape. Some icebergs have steep sides and flat tops, while others have domes and spiers.

Iceberg - what is it?

The word "iceberg" comes from Dutch and literally means ice mountain. As you know, about 91% of the entire floating ice massif is under water. It has to do with physical characteristics. Since the density of pure ice is about 920 kg/m 3 and that of sea water is about 1025 kg/m 3 , usually one tenth of the iceberg's volume is above water (according to Archimedes' principle). It is very difficult to determine the shape of the underwater part solely by looking at the part above the surface.

Icebergs typically range from 1 to 75 meters above sea level and weigh between 100,000 and 200,000 metric tons. The largest known iceberg in the North Atlantic stood 168 meters above sea level. This is the approximate height of a 55-story building. These icebergs originate from the glaciers of West Greenland and can have an internal temperature of -15 to -20 °C.

iceberg tracking

Icebergs are usually limited by winds and currents. More than 95% of the data used in sea ice analyzes comes from remote sensors on polar orbiting satellites that explore these remote regions of the Earth. Until the early 1910s, there was no system for tracking icebergs to protect ships from collisions, most likely because they were not considered a serious threat then, ships managed to survive even in direct collisions.

In 1907, the German liner "Kronprinz Wilhelm" rammed an iceberg and received very serious damage, but was able to complete its journey. However, the sinking of the Titanic in April 1912 changed all that and created a demand for systems to monitor icebergs. This is how the International Ice Patrol was formed.

New technologies control icebergs. Air surveillance of the seas in the early 1930s enabled the development of charter systems that could accurately detail ocean currents. In 1945, experiments tested the effectiveness of radar in detecting icebergs. Ten years later, oceanographic checkpoints were established to collect data; these outposts continue to serve environmental research.

11. Ice in the ocean.

Ice is a solid phase of water, one of its states of aggregation. Pure fresh water freezes at a temperature almost equal to zero (only 0.01-0.02°C below zero). At the same time, water purified in the laboratory to the maximum possible extent and in a calm state can be cooled without ice formation to a temperature of minus 33°C. But the smallest piece of ice or other tiny object placed in such supercooled water will instantly cause a violent formation of ice.

Normal ocean water, with a salinity of 35‰, freezes at minus 1.91°C. At a salinity of 25 ‰ (White Sea), water freezes at a temperature of minus 1.42 ° C, at a salinity of 20 ‰ (Black Sea) - at minus 1.07 ° C, and in the Sea of Azov (salinity of 10 ‰), surface water freezes at a temperature minus 0.53°C.

Freezing fresh water does not change its composition. The situation is different when sea water freezes. Freezing begins with the formation of thin, elongated ice crystals, in which there is absolutely no salt. Gradually, when the lumps of these crystals begin to freeze, salt gets into the ice.

Salinity of sea ice, i.e. the salinity of the water formed during its melting is on average about 10% of the salinity of ocean water. Over time, this figure also decreases, and multi-year ice can be almost fresh.

The volume of ice is 9 percent larger than the volume of water from which it was formed, because. in the crystal lattice of ice, the packing of water molecules is ordered and becomes less dense. Therefore, the density of sea ice is less than the density of sea water and ranges from 0.85-0.94 g/cm 3 . That is why floating ice rises above the surface of the water by 1/7 - 1/10 of its thickness.

The strength of sea ice is noticeably lower than that of fresh water, but it increases with decreasing temperature and salinity of the ice. Perennial ice has the greatest strength.

Ice 60 cm thick, formed on freshwater reservoirs in the dead of winter, can withstand a load of up to 15-18 tons, unless, of course, this load is applied in a concentrated manner, but in the form of, say, a caterpillar cargo platform, the bearing surface of which is approximately 2 .5 m 2.

At this point we will make a small digression, but not at all lyrical. Lake Ladoga, as is known, has only a weak relation to the oceans and ocean ice. But we want to remind you that in 1941-1942, an ice "Road of Life" was laid along this lake, which saved the lives of many tens of thousands of people. Our young readers should definitely familiarize themselves with the heroic and dramatic history of the construction and operation of this legendary road of life.

In the oceans, ice forms at high and temperate latitudes. In the polar regions, ice remains for several years. These perennial, so-called pack ice reaches its greatest thickness in the central regions of the Arctic Ocean - up to 5 meters. The melting of sea ice begins when their temperature exceeds minus 23°C. In the Arctic in summer, the thickness of ice due to the melting of its upper layers can decrease by 0.5-1.0 meters, but during the winter up to 3 meters of ice can freeze from below. These multi-year ices are gradually carried by currents to temperate latitudes, where they melt relatively quickly. It is believed that the lifespan of the Arctic ice that forms off the coast of Russia is from 2 to 9 years, and the Antarctic ice exists even longer. The ice cover in the oceans reaches its largest size at the end of winter: in the Arctic by April it covers an area of about 11 million km 2, and by September in the Antarctic - about 20 million km 2. If speak about permanent ice cover , then it makes up 3-4 percent of the total area of the World Ocean.

The ice cover may consist not only of fast ice, i.e. motionless, frozen to the shore of ice, but also mobile drifting ice. With a strong wind, coinciding in direction with the sea current, drifting ice can cover a distance of up to 100 km per day.

Falling snow often creates large drifts on the ice. The snow gradually freezes, increasing the thickness of the ice cover. Sometimes hurricane-force winds break the ice, creating high hummocks. On such ice, if we talk about the Arctic, only a polar bear can move, and even then with great difficulty.

But the ocean also contains ice formed on land. These are the so-called icebergs - huge blocks of fresh ice.(German Eisberg - ice mountain). Icebergs are supplied to the ocean by continental glaciers of polar latitudes. The largest ice sheet on Earth is in Antarctica. Its area is 13.98 million km 2, i.e. 1.5 times the area of Australia. At the same time, the area of the mainland of Antarctica itself is estimated at 12.09 million km 2. the rest is accounted for by ice covering almost the entire shelf of Antarctica. The average thickness of Antarctic ice is 2.2 km, and the largest is 4.7 km. The volume of ice is estimated at 26 million cubic kilometers. The enormous weight of ice pressed this continent into the earth's crust. As a result, a significant part of the surface of Antarctica lies below sea level. The glacier of Antarctica annually receives 2000-2200 km 3 of ice from snow and loses about the same amount to icebergs. Of course, this balance cannot be accurately calculated. Therefore, in the scientific world there is still no unequivocal answer to the question of whether the Antarctic glacier is increasing or decreasing.

Icebergs in the form of huge blocks, similar to mountains, slowly slide from the mainland into the sea, and then fall into the water with a roar. In Antarctica, the largest volume of ice in the form of icebergs is provided by two giant ice shelves advancing on the Ross and Weddell seas. For example, the Ross Ice Shelf has an area exceeding 500,000 km 2 , and the ice thickness here reaches 700 meters. In the Ross Sea, this glacier comes in the form of a huge ice barrier almost 900 km long and up to 50 meters high.

About 100,000 icebergs constantly float around Antarctica. Comprehensive, including iceberg monitoring, is carried out by 35 scientific stations operating here from different countries. Russia has 8 scientific stations here, the USA - 3, Great Britain - 2. Ukraine, Poland, Argentina and other states also have Antarctic research stations.

The international legal regime of Antarctica and other territories located south of 60°S is governed by the Treaty on Antarctica of December 1, 1959.

In the Northern Hemisphere, Greenland is the main supplier of icebergs to the ocean. It is believed that up to 15 thousand huge pieces of ice break off from the glaciers of this island every year. From here they sail into one of the busiest areas of the Atlantic Ocean.

Icebergs also break off the glaciers of the islands of the Arctic Ocean - Franz Josef Land, Novaya Zemlya, Severnaya Zemlya, Svalbard and the Canadian Arctic Archipelago.

In general, glaciers occupy 16.1 million km 2 of land, of which 14.4 million km 2 are ice sheets (85.3% - in Antarctica, 12.1% - in Greenland). In terms of area and volume of water, glaciers occupy the second place on Earth after the World Ocean, and in terms of fresh water content, they surpass all rivers, lakes and groundwater combined.

The shape of the icebergs are table-shaped and pyramidal. The table-like shape is characteristic of Antarctic icebergs, which are formed when they separate from a huge mass of ice of a homogeneous structure. When glaciers are moving relatively fast, the shape of the broken pieces often resembles a pyramid. As the uneven melting of the underwater and surface parts of the icebergs take on various, the most bizarre forms, and with a loss of stability, they can capsize.

Icebergs can reach huge sizes. Especially large icebergs are formed from the ice shelves of Antarctica. In 1987, with the help of Earth satellites, an iceberg 153 km long and 36 km wide was discovered in the Ross Sea area.

An iceberg broke off from the same glacier in 2000 and was named B-15. This giant had an area of more than 11,000 km 2. If an ice floe of such an area were on Lake Ladoga, then it would cover 63% of the surface of this large (17.7 thousand km 2) lake.

The mass of such giants can amount to hundreds of millions and even billions of tons. But this is pure fresh water, the shortage of which has long been felt by many countries.

The heat capacity of melting ice is very high. It takes 80 calories to melt 1 gram of ice, not counting the heat needed to warm the ice to zero degrees. It is no coincidence that projects for towing icebergs to the shores of such coastal states as Japan, Saudi Arabia, Kuwait, and the United Arab Emirates have long arisen. Calculations show that an iceberg of “medium” size: 1 km long, 600 m wide and 300 m in total height during the towing journey, for example, from Antarctica to Saudi Arabia, will lose no more than 20% of its volume. The initial weight of such an iceberg would be about 180 million tons (it is much less in water). If towing an iceberg of this size remains a technically difficult task, then the delivery of relatively small ice fragments with a volume of 200-300 thousand cubic meters is quite feasible and is already being carried out from time to time by the above countries.

Having broken away from glaciers, icebergs, picked up by currents and driven by winds, sometimes float away far beyond the polar regions. Antarctic icebergs reach the southern coasts of Australia, South America and even Africa. Greenland icebergs penetrate the North Atlantic up to the fortieth degree of northern latitude, i.e. latitude of New York, and sometimes further south, reaching the Azores and even Bermuda.

The sailing range of icebergs and the time of their existence in the ocean depend not only on the direction and speed of sea currents, but also on the physical properties of the icebergs themselves. Very large and deeply frozen (down to minus 60 degrees) Antarctic icebergs exist for several years, and in some cases even decades.

Greenland icebergs are melting much faster, in just 2-3 years, because. they are not so large in size and their freezing temperature is not more than minus 30 degrees.

It is unnecessary to explain what danger the floating ice mountains pose for shipping. More than once, collisions with icebergs have led to disasters at sea. But none of these catastrophes can compare with the tragedy that broke out in the early 20th century in the North Atlantic.

Today, the danger of colliding with icebergs has significantly decreased compared to the time of the Titanic. Sufficiently reliable radar and other equipment for tracking, alerting and warning of the danger of encountering icebergs is installed on sea vessels, in ports, and on artificial Earth satellites. In the northern part of the Atlantic, where busy sea routes lie, a special ice patrol . It warns ship captains about the location of large icebergs. The International Ice Patrol includes 16 countries. His ships detect icebergs, warn of the location of icebergs and the direction of their movement. The functions of the ice patrol also include the fight against icebergs, which is carried out with the help of explosions, the use of incendiary bombs, the dark color of ice blocks, for example, by applying a layer of soot to the surface of the iceberg to speed up the melting process, etc.

However, the measures taken cannot be exhaustive. Icebergs appear in the ocean according to the laws of nature. No one can fully guarantee sea vessels against ice danger. The ocean is large and often fraught with dangers, for which it is always necessary to prepare in advance.

An 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 Their existence was first reliably explained by M. Lomonosov. Due to the fact that about 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, constantly accumulating layers of ice and, from time to time, sending excess to the Atlantic Ocean. Under the influence of currents and winds, ice blocks are sent to the south side, 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. At this latitude, transoceanic sea routes pass.

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 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.

A 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 km2. 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

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 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. In the thickness of the ice there are significant inclusions of rocks, sand or silt that got into it while moving around the island or mainland.

Threat to ships

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 arises 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 contact with ships and aircraft, collecting information about icebergs and warning of danger. Predicting movement is almost impossible. To make them more noticeable, icebergs are marked with bright paint or with an automatic radio beacon.