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 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 of fresh water. This issue is especially relevant for the dry coasts of Australia and South America which are close to Antarctica. Iceberg water is immediately drinkable, and its cost will be lower than desalinated seawater.
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I saw icebergs only on the TV screen. Probably the most famous iceberg among those shown in films is the one that sank the Titanic. I still couldn’t understand how the sailors didn’t notice the huge floating block of ice. That's when I became interested in the formation and structure of icebergs.
What is an iceberg and how is it formed?
Floating ice blocks are formed by breaking off from glaciers (shelf, cover, outlet). In the Northern Hemisphere of the Earth, the birthplace of icebergs is considered to be the Greenland glaciers, which are thrown into Atlantic Ocean up to 300 km³ of ice per year. Greenland icebergs look like real ice mountains with a pyramidal or dome shape. These icebergs reach up to 40° north latitude, but sometimes end up further south, drift onto transatlantic sea routes and pose a threat to ships. As I already mentioned, in 1912, the Titanic sank due to a collision with an iceberg.
The Antarctic ice sheet is creating more icebergs. They float in the ocean for 6–12 years, then they fragment, melt and shrink. The most famous icebergs in Antarctica are table icebergs; they have vertical walls with horizontal layers of firn and flat tops.
Colored ice mountains
I never would have thought that icebergs could exist different colors. But that's true. The color of an iceberg directly indicates its age. The color of the iceberg can be:
- matte white;
- white with a blue tint;
- soft pink;
- black.
Matte white icebergs are the youngest (just broken off); as they become saturated with air, they acquire a bluish tint. In addition, do not be surprised by the striped or marbled color of the ice.
Black Glacier Shard
For the first time about the black iceberg in printed edition James Cook reported. Later, other sailors talked about black blocks near Antarctica. As it turned out, the black color of the icebergs is associated with the activity of volcanoes in the South Shetland Islands. The ice is covered with a layer of volcanic dust, which is not washed off even by salty sea water.
The origin of this iceberg isn't the most romantic, but I think it looks amazing!
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When they talk about icebergs, a scene from the movie “Titanic” immediately pops into my head, when the largest steamship in the world at that time, colliding with a small iceberg, crashed. It's a terrible picture, to be honest with you. But how is it that a seemingly small piece of ice caused so much trouble... But not everything is so simple, icebergs keep many secrets and mysteries.
The concept of icebergs
An iceberg is a large, free-floating piece of ice in the ocean. Huge blocks of ice break off from the ice edges and drift under the influence of currents and winds. Icebergs usually form near Greenland and off the coast of Antarctica. Thus, depending on the place of birth, such groups of icebergs are called Southern or Northern. Find out exactly how much at the moment time in the world of icebergs is impossible, since this figure is constantly changing. Icebergs can reach enormous sizes, so I learned that in 2000 an iceberg with an area of 11 thousand broke off from Antarctica square meters!!!
Types of Icebergs
There are several types of icebergs, including:
- shelf icebergs;
- icebergs from outlet glaciers;
- icebergs of cover glaciers.
The first type is huge in size and has a flat surface. Place of birth: Antarctica. The second type can be found both in the south and in the north. The form can be very different. The third type of icebergs has a flat surface with a bevel on one side.
I was surprised when I learned that some large icebergs can even form internal lakes, their own rivers and caves!!!
Global warming
Recently, more and more ice giants have begun to form on the planet. Plus, the new icebergs have become much larger than their predecessors. This is one of the signs of global warming on Earth; glaciers are disappearing. Huge blocks simply thaw from the glaciers and drift in the ocean, slowly melting. Such natural antics entail a lot of problems.
Thus, according to scientists, every hundred years, the level of the World Ocean rises by 1 meter. In 5 thousand years, when all the glaciers melt, almost all the land will go under water.
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I really enjoy rereading Hemingway. And recently I remembered that one of his stories, “The Old Man and the Sea,” is called an iceberg work, because part of it is always in sight, but most of it is hidden under water and is a mystery. I became very interested in how this mystery was born, and why so many sea vessels suffer from them.
How are icebergs born?
The main birthplace of these ice mountains is Antarctica, but there are also those that break off from ice shelves in the Arctic. Although, it is true, it is worth saying that Antarctic icebergs are much larger and more dangerous than their Arctic brothers. There are several types of icebergs in nature, but almost all of them are formed by the sliding of ice crust into the sea or ocean, where they float until nothing remains of them.
Under blocks of ice, softer layers can form, similar in density to honey, or even entire rivers, which provoke this movement. And sometimes very old layers break through and shift new ones, which, under the weight of their weight, also begin to slide into the ocean.
The process of education occurs at a certain speed. And this speed can be influenced by the following factors:
- global warming;
- changes in air circulation in the atmosphere;
- earthquakes;
- nuclear tests in the Pacific Ocean, etc.
Icebergs today
Not much time has passed since the Titanic sank. And science has advanced, making it possible to determine the location of these ice mountains as quickly as possible. But this does not completely solve the problem, especially since they are increasing in number and size. Due to increasing temperatures and certain geological processes, larger and larger icebergs began to break off and float into the vastness of the World Ocean. For example, a piece with an area of 11,000 square kilometers broke off from the Ross Glacier in 2000. Also, when they melt, something that has been stored in them for many centuries is released, including viruses.
Research work on the topic:
“Amazing natural phenomena. Iceberg."
completed
3 "B" class
Municipal educational institution "Secondary school No. 83"
Saratov
Research topic:“Amazing natural phenomena. Iceberg".
Purpose of the study: learn more about the world around us. Understand the connection between natural phenomena and humans. Learn to appreciate what surrounds us
Tasks: Find information on this issue. Understand what benefits can be derived from this natural phenomenon.
1. Introduction.
2. Birth and life cycle icebergs
3. Movement of icebergs.
4. How icebergs affect our lives.
5. Benefits of icebergs.
6. Interesting facts.
7. Threat.
8. Conclusion.
9. List of references.
Introduction.
In our environmental lesson we studied the properties of water. I learned that this unique liquid can be in three states:
liquid
gaseous
hard
It was the solid state that interested me, because the ice into which it turns does not sink, but floats. I thought, how can this be? It turns out that the process of freezing water is very unusual. As the water in lakes and seas cools, it becomes heavier and moves downward, but when the water reaches the freezing point, the reverse process occurs. Now it becomes easier and rises more cold water. Having turned into ice, it floats on the surface. I decided to conduct an experiment. I froze an ice cube and then threw it into a glass of water. Surprisingly, the ice cube floated on the surface. The piece of ice on the water reminded me of the icebergs I saw on TV. But how little I know about them. I decided to do a survey among my friends what they know about icebergs. I interviewed 15 people. Here is the survey table:
|
They don't know anything about icebergs |
Have some idea about them |
Have accurate, extensive information |
As we can see, few people have an accurate understanding of icebergs. I myself first learned about icebergs when I watched the movie Titanic. I remember the moment of the collision well.
“ICEBERG is straight ahead!” - shouts the alarmed lookout. The sailors on the captain's bridge responded immediately. The engines reversed to avoid a collision. But it's too late. The starboard side of the ship received a fatal hole.
I asked myself: how and why do icebergs appear? What can be done to protect people at sea from the danger of collision with it? And how can they influence people's lives? I started looking for information on this issue, and this is what I found out.
Birth and life cycle
Icebergs are like giant ice cubes of fresh water. They are born from glaciers and cover ice in the North and Antarctica.
One of the places where icebergs “emerge”
I was surprised to learn that the Antarctic ice cap produces about 90 percent of the earth's icebergs. It also produces the largest icebergs. Sometimes they rise 100 meters above the water level and can reach more than 300 kilometers in length and 90 kilometers in width. Large icebergs can weigh between 2 million and 40 million tons. This is power! And like snowflakes, no two icebergs are alike. Some are table-shaped, that is, with flat tops. Others are wedge-shaped, pointed or dome-shaped.
Usually only one-seventh or one-tenth of the iceberg is visible above the water. This is especially true for flat-topped icebergs. This all reminds me of my ice cube floating in a glass of water. However, the ratio of ice above and below water is different, depending on the shape of the iceberg.
In general, Antarctic icebergs have flat tops and sides, while Arctic icebergs are often irregularly shaped and turret-like. Arctic icebergs, most of which originate from the vast ice cap that covers Greenland, pose the greatest threat to humans as they can drift along the transatlantic shipping route.
How do icebergs form? In the northern and southern regions of the earth, the resulting snow cover often does not have time to melt, and cold rain does not evaporate. This causes the layers of snow that accumulate on the surface of the earth to turn into glacial ice. Year after year, as more snow and rain fall, constant compaction occurs. This creates massive ice fields over vast areas of land, such as in Greenland. Eventually, the ice becomes so thick and hard that it causes the heavy glacier to slowly slide down the high slopes into the valleys and then out to sea. The age of the iceberg from the moment of snow compaction at the sources of the glaciers until the start of drift is calculated in centuries.
I imagined a river of ice moving very slowly over the uneven terrain, like cold molasses. Already containing vertical cracks, this giant ice sheet will be a spectacular sight once it reaches the coastline. Due to the simultaneous effects of tides, wave movement and underwater destruction, a huge block of freshwater ice, which can extend approximately 40 kilometers out to sea, will break away from the glacier with a deafening roar. And then the iceberg was born! A person who observed it described it as a “floating crystal castle.” This must be an amazing sight.
In the Arctic, between 10,000 and 15,000 icebergs form each year. However, relatively few reach the southern waters off Newfoundland. What happens to those icebergs that reach this area?
Movement icebergs
Most of the icebergs that break away from the massif are carried away by the ocean current on a long journey, then turns some to the west, others to the south and, ultimately, brings them to the Labrador Sea, nicknamed Iceberg Alley. It would be great to ride on such a unique ice ship. Icebergs that survive after drifting for approximately two years from their birthplace into the open Atlantic towards the Labrador Sea and Newfoundland last a very short time. Once in warm waters, they begin to quickly deteriorate: melt, shrink and break into pieces. When I carried out the experiment, the ice cube really melted quickly.
It is typical that during the day the ice melts and water collects in the cracks. At night, the water freezes and expands in these cracks, causing the iceberg to break into pieces. This dramatically changes the shape of the iceberg and moves its center of gravity. Then the block of ice turns over in the water, presenting a completely different ice sculpture.
As this cycle continues and the ice castles shrink in size, breaking into pieces, they give rise to their own icebergs the size of an average house, and growlers the size of a small room. Some smaller growlers can even flounder in the shallows of shorelines and small coves.
However, the environment in more southern waters will cause the iceberg to rapidly disintegrate into small pieces of freshwater ice that will become part of the great ocean. However, until this happens, icebergs must be handled with care.
How icebergs affect our life
Fishermen who depend on the ocean for their livelihoods say icebergs are a nuisance and a danger. One fisherman said: “Icebergs may be a tourist attraction, but they are a threat to fishermen.” The fishermen returned to check their nets only to find that an iceberg, carried by the tide or current, had torn their expensive nets and released their catch.
Icebergs deserve respect. “I advise you to keep your distance,” says the captain of the sailing ship. “Icebergs are very unpredictable!” Tall icebergs can break off huge chunks, or when the icebergs hit the bottom, large chunks can break off and float up towards you. The iceberg can also spin and capsize - all of which could spell disaster for anyone who ventures too close!”
That icebergs are scraping ocean floor, represents another cause for concern. “If the iceberg's sediment is almost equal to the depth of the water, then it is known that its base can dig long and deep channels. In oil-producing areas, this has a devastating effect on bottom-dwelling installations such as wellheads,” said one person who observed the icebergs.
I thought about how I could prevent the damage that icebergs could cause. I heard that in some cities they use lasers to knock icicles off the roofs of houses. This makes the job easier for the people who keep track of it. I wondered if something like this could be used to cut off pieces of the iceberg that could cause harm. It would also be good to track wandering icebergs and warn people about a possible collision with them. But it turns out that such work is already underway.
International ice patrol
After the tragedy of the ocean liner Titanic, the International Ice Patrol was formed in 1914 to locate icebergs, predict their movements based on knowledge of ocean currents and wind directions, and then warn people about the ice. In order to provide protection from these "crystal" giants of the sea, every effort is being made to accumulate knowledge about characteristic features and behavior of ice. The technology used includes visual and radar surveys from aircraft, ice detection reports from commercial vessels, satellite photography, oceanographic surveys and forecasts.
The benefits of icebergs
Maybe we would live better without icebergs. However, not everything associated with icebergs is bad. I found information on how you can use icebergs for the benefit of people. One Newfoundlander noted: “A long time ago, when not everyone had a refrigerator, people in some coastal villages would bring small pieces of iceberg and put them in their wells to keep the water as cold as ice. They also served another purpose: chunks of ice were stored in boxes with sawdust to be used in making homemade ice cream.”
How else could we apply them in our lives? I'm thinking, since icebergs are frozen fresh water, couldn't we use it to deliver it to people who need it? It would be nice to attach, not the largest iceberg, to a cargo ship and tow it to the shore. Of course, part of the iceberg will melt along the way, but some part will float to its destination and can be useful. Or, on the spot, right in the sea, cut off a piece, melt it and pass it through a filter, and only then deliver it in bottles to the shore.
Since these “ice palaces” are impressive with their beauty, many people want to see all this beauty with their own eyes. On Newfoundland's rugged coastline, they look for a spot with panoramic views of the Atlantic to admire the giants of the sea. Cameras are clicking to capture this moment on film. Icebergs come in amazing sizes and even colors. I would love and with great pleasure to look at them in their natural environment.
By the way, the pale blue tint of some icebergs appears due to the re-freezing of melt water, which fills the gullies in the icebergs. Ancient ice blocks reflect sunlight and change color depending on the angle at which the light hits them.
Some icebergs are a favorite habitat of penguins.
Interesting facts.
To understand the full power and greatness of icebergs, I want to give some interesting facts about their sizes.
Two or three medium-sized icebergs contain a mass of water equal to the annual flow of the Volga (the annual flow of the Volga is 252 cubic kilometers).
The largest icebergs are found in Antarctica. In 1956, the American icebreaker Glacier circumnavigated an iceberg 350 km long and 40 km wide.
In October 1999, an iceberg the size of London broke off from Antarctica.
90% of all fresh water on our planet is stored in the eternal Antarctic ice. Almost 5 thousand icebergs break off from Antarctic glaciers every year - this is 100 million tons of frozen fresh water. Among them there are sometimes giants, comparable in size to the islands. For example, in 1956, an iceberg was discovered in the South Pacific Ocean, the length of which was 335 km and the width of 97 km. And in the 58th year of the last century, a record high iceberg with a height of 167 m was discovered near Greenland. Similar record holders appear constantly. In the fall of 1987, an ice floe 159 km long and 40 km wide, with a total area of 6200 km and a thickness of more than 220 m, broke off from the ice sheet of Antarctica. The fresh water flooded from this iceberg would be enough to meet the needs of Moscow for about 650 years. Currently, this iceberg is gradually falling apart, drifting in the Ross Sea, and has a size of 95 x 35 km, with a total area of 3365 km.
Threat.
I was very concerned that this amazing natural phenomenon was in danger. The fact is that due to the “greenhouse effect”, glaciers and icebergs are rapidly melting. It would be a shame if over time people will no longer be able to admire these floating castles. In addition, this poses a huge threat to the entire planet. After all, if all the glaciers melt, the level of the world's oceans will rise significantly, which may lead to various natural disasters. I tried to find out what the “greenhouse effect” is and what causes it.
The Earth's atmosphere, like the glass of a greenhouse, does not release the sun's heat. The sun heats the earth, but the heat carried by infrared radiation cannot escape freely from the atmosphere. Greenhouse gases block the radiation and reflect it back to the ground, causing the air near its surface to warm up.
I am very sorry that our planet may be in danger. Since many people believe that this problem is caused by man, can't it be solved by man himself? What can I personally do? It turns out that a lot depends on everyone’s efforts. For example, car use and deforestation contribute to global warming. Our family doesn't have a car, but those who do might think they can contribute to the environment by using it only when necessary and walking occasionally. Also, the energy consumed by various devices in standby mode leads to increased operation of the power plant, which releases gas that contributes to the “greenhouse effect.” Therefore, I personally can make sure that I do not leave appliances in “standby” mode in our house and use electricity wisely. I am glad that I can contribute to the conservation of our planet and the icebergs that I have met.
Conclusion.
During the research work I learned a lot interesting information about icebergs, how they appear, what they are like. As we gaze upon these towering, sparkling wonders of the sea we marvel at these amazing creations. I would really like people on our planet to learn to see the beauty of natural phenomena, appreciate what surrounds us and remember that man and nature are interconnected. The main thing is to learn to live in harmony with each other!
References:
1. Children's encyclopedia "Cyril and Methodius"
2. Periodical publication of Awake magazine.
3. Website: www.
After the famous blockbuster Titanic, no one needs to explain what an iceberg is. Of course, a huge ice mountain floating in the open sea-ocean.
But in fact, a lot of this natural phenomenon remains unknown to the general public. For example, you know...
Why does an iceberg float?
More precisely, why does ice float on water? If you melt sugar and throw a piece of refined sugar into it, it will drown. Solid wax sinks in its own melt. Thousands of other substances behave in exactly the same way. But water behaves differently.
Unlike many other liquids, its molecules do not float in a glass or river on their own, but each is connected to four or five others. And when it freezes, it turns into crystals, where the “packing” of molecules is no longer so dense. That is, ice has a lower density than water, which is why it floats. It wouldn’t surprise you if a piece of wood or sunflower oil? They also have a lower density than water. But when ice freezes, it also traps air bubbles. How can he not swim!
“An iceberg grows out of the fog like an icy mountain...”
An iceberg can emerge from the fog, from the darkness, from around a corner. But where do such mountains of ice come from? Even if the sea freezes, flat ice floes will appear, albeit thick, but not such shapeless hulks as icebergs.
In fact, the sea has nothing to do with it. Because icebergs are born... on land, in the polar North and Antarctica. The eternal snow that covers the northern mountains, for example, Greenland, is compressed and turned into an ice sheet over a kilometer thick.
Under their own weight, the glaciers slowly slide down and their edges hang over the ocean. Giant fragments break off from them with a roar. Sometimes, even on the slope, a crack runs across the ice tongue and its multi-ton “tip” slides into the water. And then the fate of the iceberg is decided by winds and currents.
While it moves through shallow water, its sharp underwater edges can plow deeply seabed. Once in open waters, it drifts. The underwater part is gradually overgrown with plant organisms, and small crustaceans are attached to it. Birds travel on top of icebergs. 
The most impressive thing about an iceberg is its enormity. Despite the fact that no one has ever seen the entire iceberg from top to bottom: after all, over 90% of its mass is hidden under water. A 75-meter surface height and a mass of 200,000 tons are not uncommon in the world of icebergs. The largest recorded in the North Atlantic had an apparent height of 55 stories. In 1956, an iceberg wandered in the south Pacific Ocean, which cannot even be called a mountain - it was real island the size of Ireland and larger than Belgium. In 2000, an iceberg weighing over 3,000,000,000,000 (three trillion!) tons floated near Antarctica.
"And this iceberg will melt..."
The iceberg is not doomed to melt. It can be frozen for a long time in the thick ice covering the sea. Then thaw, swim and freeze again. Inside the ice mountain, the temperature stays at –15…–20°C. However, the outer layers gradually melt, especially if the iceberg ends up in warm latitudes.
When melting, huge caves are formed inside the iceberg, blocks break off from the ice monolith with noise. By the way, when melting, an iceberg makes short hissing sounds. These frozen compressed air bubbles are released and burst, jumping out to the surface of the ocean. Eventually, all the millions of tons of frozen fresh water turn into liquid and dilute the ocean. Icebergs live on average for two years.
Since the 1950s, experts have recorded a general decrease in Antarctic ice cover. Its fragments go into the ocean like icebergs and, of course, do not return. Of course, new ice grows instead, but the overall stability of the ice sheet decreases. Scientists fear that huge glaciers will creep toward the water, and no one knows what this will lead to.
Keep your eyes open!
It is clear that even not very large icebergs are dangerous for shipping. Nowadays, large ships are equipped with radars that warn the crew of possible unpleasant surprises. 
Since the beginning of the 20th century, an international system for detecting and tracking icebergs has been established. Now these tasks are performed by spacecraft around the clock, regardless of earthly weather. Each “newborn” iceberg receives its own code name (such as D-16), and the fate of the ice mountain is monitored. It broke up - they “monitor” every large fragment. It seems that the fate of one and a half thousand people who died on the Titanic taught humanity something.
An iceberg is a huge floe of ice floating in the world's oceans.
Where do icebergs come from?
Huge pieces of ice break off from the glaciers that cover the continents and float freely. For example, northern icebergs break off from the Greenland ice sheet, and southern ones from Antarctica, and southern icebergs are much larger in size than northern ones. Not only does the duration of existence and the range of its voyage depend on the properties of an iceberg, it also depends on factors such as the direction and speed of the current in the ocean.
The largest in size and frozen down to -60 C, the icebergs of Antarctica “live” for many years, sometimes even more than a decade. Whereas Greenland icebergs are slightly smaller in size and their deep freezing temperature reaches -30C. They live much shorter, and their melting period is 2-3 years.
Ice is much lighter than water, which explains why even the deepest bodies of water do not freeze completely in winter. If it were the other way around, then, in fact, the ice falling to the bottom would displace the lower layers of water to the surface, and gradually all the water in the reservoir would simply freeze.
But when water freezes, the exact opposite happens. When water transforms into ice, its volume increases by about ten percent, and as a result, the density of ice is much less than that of water. This explains why ice floats on the surface.
At considerable depths of the world's oceans, the water temperature is below zero degrees, but the water there does not freeze. This is interpreted by the pressure that the upper layers of water form.
For the first time, Mikhail Lomonosov answered the question why icebergs do not sink. The density of the iceberg is 920 kg/m?. Additionally, an iceberg or block of ice is made of fresh water and is separated from ice shelves.
Due to the fact that sea water is denser than an iceberg and does not sink completely. And then it is important to know that only a tenth of it floats on the surface of the water - the top, everything else - 90% of this block of ice is hidden under water.
Meeting him is very dangerous for ships on the high seas. If the ship does not notice the moving iceberg in time, then in a collision it can receive very serious damage or even die.
Who wants to fly over Iceland (Jokulsarlon glacier lagoon. 360° aerial panorama) click on the link above. And then we’ll look at photos of beautiful icebergs and learn something interesting about them.
“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. The main mass of the broken ice mountain either rose high out of the water, then dived again, disappearing from sight. This was repeated many times, and from Pieces of it were breaking off all the time, and it became smaller and smaller. When the roar died down, among the numerous white fragments there remained a beautiful blue mountain, like the core of a flower among the sleeping petals." This is how the famous Australian polar explorer, conqueror of the South Magnetic Pole and the southernmost volcano of the Earth - Erebus - Douglas Mawson describes the picture of the birth of the iceberg so poetically and at the same time accurately documenting it.
Formidable floating ice mountains are huge masses of ice that have broken off from glaciers sliding into the sea or, as Mawson describes, from the edges of the giant ice sheets covering Antarctica and Greenland The moment of iceberg breaking off is a grandiose and terrible sight, accompanied by an eerie roar reminiscent of cannon fire All The surface of the sea becomes very rough at this time, and the resulting waves are so large that they capsize boats and throw small fishing vessels far away.
ICEBERGS, large blocks fresh ice, broken off from glaciers descending into the sea or a periglacial lake (ordinary floating ice floes 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 direction of iceberg drift 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 monitored the movement of a giant iceberg for ten years, which had a length of 120 kilometers and a height of 90 meters. And in 1927, a Norwegian whaling ship spotted an ice island reaching a length of 170 kilometers. But the largest iceberg was discovered in Antarctic waters in 1956. Its length was 385 and its width was 111 kilometers. In area it was equal to almost half of a country like Slovenia, or three Luxembourg!
The tallest iceberg was found 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 the air bubbles found in ice crystals, icebergs have good buoyancy. At the same time, only one-eighth of the ice mountain is visible on the surface of the sea; the rest of its mass is under water. Therefore, icebergs are moved by the force of sea currents, and not air flow, 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 - the iceberg will crush it like a matchbox!
Antarctic icebergs rarely travel far north into the Indian Ocean and South Pacific, where major shipping lanes lie, although they have been encountered as far as 160 km south of Australia. In the South Atlantic, icebergs drift with the Falkland Current from Cape Horn to Cape Good Hope. The North Pacific Ocean is separate from the Arctic Ocean (except for the narrow Bering Strait) and is free of icebergs. 10-15 thousand icebergs break off from the West Greenland glaciers every year, many of them coming from East Greenland and the northeastern 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 along busy North Atlantic shipping lines and can be seen year-round in areas north of 43°N latitude. Sometimes in the south they were found up to the latitude of the Azores.
In clear weather, thanks 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 over 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 negligence, and this was the reason for the very strict safety regulations that still apply to navigation. On the moonless night of April 14-15, the ship continued to move at a speed of 22 knots, despite receiving radio warnings about the presence of floating ice in the area. It hit the iceberg 40 seconds after it was spotted and sank 2 hours 40 minutes later, claiming 1,513 lives.
The “parents” of icebergs are the vast glaciers of Greenland, Spitsbergen, Franz Josef Land and the island of Canada. From there, 18 thousand icebergs “start” their voyage every year.
The process of iceberg birth is slow. The glacier area is slowly sliding onto the water, driven by bad weather and washed away by the oncoming waves. Then the broken part of the glacier falls into the water with a roar. Air bubbles located in the iceberg, and also due to the fact that ice is lighter than water, the iceberg has good buoyancy.
The process of iceberg birth is accompanied by very interesting and unlike anything else sounds
On the surface of flat icebergs they are often found big lakes, sometimes up to twenty kilometers in diameter. On such ice islands there are also rivers and streams flowing into the sea 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, caves are “inherited” by an ice mountain 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 goes out onto the plain, and then long subglacial cavities remain inside it, which over time approach the shore and set off together with the ice block containing them on a long voyage.
The interior of these subglacial, or more precisely, “intra-ice” caves is a spectacle of amazing beauty. Here's what one of the participants in the 1965 Soviet Antarctic expedition says about it:
"A rounded corridor about three meters high went deep into the ice mountain. The wavy walls were made of smooth, as if polished ice. An extraordinary bluish-blue light passed through the entire ice massif, flowed softly, shimmering in the ice walls. The reflections of the 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 clouds set us in 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 hanging from the ceiling and completely covering the walls. It was frost, similar to that which can be seen on the windows on a frosty day, but only increased many times.
Ice needles, like flowers of the most bizarre shapes, sparkled and sparkled in the blue diffused light. It was scary 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. Of course, the fire from the lit match seemed so bright in contrast to the bluish lighting of the cave, but this did not make it any less beautiful."
Once our sailors even met a “singing” iceberg off the coast of Antarctica. The water washed through the holes in it, in which the wind staged rather melodic “concerts”, as if playing a huge flute.
Sometimes icebergs resemble the outlines of medieval castles or watchtowers. They are called pyramidal. But flat, so-called table icebergs are more common. Sometimes you come across 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 went 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 broken off from the Inylchek glacier that formed the lake. One of the expedition scientists 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 shipping. Greenland icebergs are especially dangerous in this regard, which are driven south by winds and currents to the shores North America where there are busy shipping routes. 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, causing thick and long-lasting fogs. Meanwhile, icebergs up to 20-30 meters high (and these are the majority in the North Atlantic) even on a clear night are visible 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 .
Greatest maritime disaster The 20th century forced maritime powers to take measures to avoid similar tragedies in the future. As a result, the International North Atlantic Ice Patrol was created in 1913. Patrol boats and aircraft watch for icebergs and radio warnings for passing ships. Over the course of a year, the patrol identifies 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 provide a complete 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 its passengers and crew. 95 people died. Approaching too close to a floating ice mountain is also dangerous. Icebergs melting from below gradually lose stability and can suddenly capsize, destroying a ship that approaches carelessly.
The capsizing of the iceberg was observed from the board of the motor ship "Ob" in the Davis Sea, and eyewitnesses describe this event as follows:
“In calm weather, a strong roar was heard, 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 part and fell into the water with a roar. When The surface part of the iceberg noisily sank into the water, and a rather large swell began to emanate from it, causing the ship to rock on the surface of the sea, among the debris, a new hilly and uneven top of the iceberg slowly swayed.
Many large icebergs live in the sea for several years. In Antarctica, large colonies of penguins and other seabirds often settle on them. Some even make nests there. The durability of icebergs gave people the idea of trying to use them to supply fresh water to arid countries in Africa and Arabia. This is how a project arose to tow large icebergs by special ships to the shores of the Persian Gulf in order to use the water generated during their melting for water supply and irrigation of fields. It is estimated that the amount of water generated by the melting of one medium-sized iceberg is equal to the annual runoff 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 for protection from the raging waves, taking shelter on their leeward side from the storm. And pilots of Antarctic expeditions sometimes choose their flat surface as a landing strip. Of course, you must always remember the treacherous nature of the ice islands and be on your guard. After all, the behavior of icebergs is unpredictable and you can expect a surprise from them at any moment.
This is how an iceberg once “joked” with the Canadian steamship Porsche. This happened in 1893. The Porsche was on a cruise with large group 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 photo close up. But as soon as the ship sailed close to the iceberg and the tourists clicked their cameras, something incomprehensible happened. An unknown force began to lift the Porsche out of the water. A few seconds later, the ship was already above the surface of the sea on a huge ice ledge of an iceberg, which had previously been under water. Apparently, the ice mountain swayed in the water, and when the steamer approached it, the tilt allowed the ship to sail over the underwater cornice. Then the iceberg began to roll in the other direction and lifted the ship into the air. Fortunately, this did not last long. When the iceberg tilted back again, the ship found itself in the water without even receiving minor damage. Full speed ahead the captain directed the steamer away, away from the ice trap. The passengers didn’t even want to think about what could happen if the iceberg capsized.
It must be said that, despite their well-deserved gloomy fame, icebergs make a striking impression on the traveler seeing them for the first time with their unearthly, fabulously romantic beauty. Their shapes can be the most bizarre and unusual: either a giant snow-white swan or a hilly island with wide valleys, lacking only a cozy village, or an island with high mountains, gorges, waterfalls and steep cliffs forming 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 anyone who happened to see their fantastic outlines on the dark surface of the sea, reminiscent of floating enchanted castles, blue-white, 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 out the most favorable path for the iceberg in the ocean in order to use favorable currents and winds, and make the iceberg melt more slowly.
