How are icebergs formed? What is an iceberg? The further fate of the icebergs

I don’t think I’m original, but I immediately remembered the tragic fate of the Titanic, which, if it had not encountered one of these boulders, probably would have remained one of the ordinary ships. So what is this ice floe that sank the most “unsinkable” ship?

Why do icebergs float?

Every iceberg is, in essence, a huge floating piece of ice that has broken off from a glacier. Most of them reach truly impressive sizes, towering 80-100 meters above the water. The most interesting thing is that this is only 15-20%, and therefore the height of such giants reaches 500 meters! Actually, this is where the expression “tip of the iceberg” comes from.

Buoyancy is explained by the unique properties of frozen water. For example, the same piece of sugar, thrown into its own melt, will instantly sink to the bottom, but ice behaves completely differently. This is explained as follows:

• Water is not represented by a set of individual molecules, but by bundles of several, usually no more than 5.
• At the moment of freezing, they turn into crystals, therefore the bundle becomes less dense.
• In addition, when freezing in crystal lattice air bubbles are embedded.

Why shouldn't ice float then?

How are icebergs formed and what dangers they pose?

Icebergs are mainly found in waters near the polar circles, as this is where they form. They break off from the edges of glaciers, fall into the water and begin their long journey. Even relatively small blocks pose a danger to navigation, despite the fact that modern ships are necessarily equipped with special locators. Since the latitudes where they occur are famous for fog, it is almost impossible to see the block ahead, which means there is a high risk of collision. Sometimes, when hitting the side, the ice floes turn over, and this also does not bode well.

Today, scientists are trying to track icebergs using satellites. Newly discovered ones receive a code name, and the data is transmitted to navigation centers. “Surveillance” is carried out until the block melts, and this process can last for years.

The Arctic and Antarctic are natural “enterprises” for the production of unique environmentally friendly products – icebergs. Antarctic icebergs are much larger than their Arctic counterparts. These are huge masses of ice, sometimes their area reaches several thousand. square kilometers! Some icebergs are comparable in size to the Crimean Peninsula.

Iceberg danger

In the desert waters of Antarctica, icebergs pose no particular danger. If they are of interest to anyone else, besides the captains of ships that rarely approach the White Continent, then perhaps glaciologists. Each large Antarctic iceberg receives a name at “birth” followed by last day surveillance is carried out from aircraft and space satellites. Where a big problem- Arctic icebergs. They drift along the shipping lanes of the North Atlantic. Once upon a time, sailors had to rely only on the vigilance of the lookout.

At the beginning of the 20th century, ship sirens began to be used. Their sound reflected from the surface of tall icebergs, warning of danger. And if you came across a low specimen, then you had to rely solely on luck. After tragic death As a result of the Titanic's collision with a huge block of ice in 1914, the International Ice Patrol was created. 13 countries have agreed to patrol the North Atlantic basin. Until the 1940s, patrols in the region were carried out by ships. Since the end of the Second World War, observations have been carried out mainly from the air. Having discovered an iceberg, the patrol determines its exact location, predicts its drift and then transmits radio reports to nearby ships twice a day.

When I hear the word "iceberg", then I remember my favorite movie “Titanic”. Remember how in 1912 a large liner collided with an iceberg? As a result of this disaster, 1,490 people died. These large blocks of ice amaze our imagination. They are found only near Antarctica and the Arctic, so few people manage to see them.

How do icebergs appear?

Translated from German language iceberg means " ice mountain" This mountain of ice floats on the ocean. They formed as a result of calving from a cover glacier. A block of ice breaks off and begins to float across the ocean. Thanks to sea ​​current, they are sailing away from their “old place”. They begin to melt in the water. Only the largest of them can swim in the ocean some years. I read that the “deadly iceberg” for the Titanic floated for about 10 years. So imagine how big it was! Scientists have calculated that there are about 40 thousand of them floating in the World Ocean.

90% of the iceberg is underwater, therefore we see only a small part of them on the surface. All these “ice pieces” contain fresh water. A floating iceberg is a great danger for ships in our time. There have been cases in history when they turned over and violated the integrity of the ship.

Types of Icebergs

All floating blocks of ice Depending on the conditions of occurrence and form, they are divided into types:

• shelf icebergs– are formed as a result of the breaking off of part of the ice from Antarctica. Their shape is relatively flat, and their sizes are huge. The most famous are the Ross and Filchner-Ronne ice shelves. Their total area is larger than that of Germany;
• icebergs from outlet glaciers– their shape is similar to a pillar. The upper part is convex and has many cracks and irregularities. When viewed from afar, they look like mountains;
• icebergs of cover glaciers– they are almost flat and inclined towards the current. They swim near Antarctica and Greenland.

Icebergs change color depending on conditions. If it has just broken off, it will be matte white. Upon contact with air upper layer turns purple. The water changes color to blue.

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 the sea routes that 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 calving process large areas 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.

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. In the same time, warm water affects 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 sea ​​routes. 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: