Whether the sea freezes or not. At what temperature does sea water freeze? Photos and videos with experiments. What does sea water consist of?

IN Kerch Strait— complex unstable ice regime. Engineering survey on this score fulfilled . Decrease in temperature during eastern and northeast winds creates conditions for ice formation in the strait in winter. In the open part Sea of ​​Azov and in the northern part Kerch Strait complete freezing is observed only in harsh winters. The final clearing of ice in such cases occurs on average by February 28, although after harsh winters on the approach to the Kerch Strait, encountering ice is possible in mid-April.

clickable

The bridge crossing may contain both weakened and consolidated ice. So in severe winters, bridge supports may be exposed to ice. different types- exposure to moving ice from Sea of ​​Azov, hummocks, movement of the ice field and thermal expansion of ice. When calculating ice loads on bridge supports, these factors were carefully studied.

Based on the results of model studies carried out in conditions of continuous, level ice, broken ice and hummocks, the values ​​of the five components of the global ice load were obtained for various depths of the water area, as well as the speeds and directions of ice drift. All this was taken into account when developing the final design solutions.

The spans between the supports are quite large, so most likely no additional funds will be required to clear the water area. To control the ice situation during the freeze-up period, monitoring of the ice situation is organized. If necessary, icebreaker-type vessels located in the port of Novorossiysk are ready to arrive within 8-10 hours to crush the ice fields.

Sea of ​​Azov freezes every year. It is common for ice to appear and melt several times during one season. In the depths of winter, ice can cover the entire water area Sea of ​​Azov and form almost continuous fast ice - a stationary ice mass along the coast. Early 2017 Sea of ​​Azov almost completely frozen.
Sea of ​​Azov- the shallowest and most distant sea from the ocean in the world. His average depth- about 7 meters, the deepest areas reach 13.5 meters. To imagine how shallow the sea is, it is enough to compare it with Black Sea, the average depth of which is 1`240 meters.

Photos Kiziltashsky And Bugazsky estuaries near Blagoveshchenskaya village and plot Sea of ​​Azov near village Golubitskaya And Peresyp village made by Alexey Shkolny in mid-February 2017.

Water Sea of ​​Azov contains three times less salt than World Ocean average. In critical situations, it can even quench your thirst. The low volume of salt is formed due to the abundant influx of river water: up to 12% of the water volume enters the Azov from the rivers Another factor is difficult water exchange with Black Sea. Due to low salinity, the sea freezes easily.

Every year when the water temperature drops below zero, Sea of ​​Azov covered with ice. Freeze-up - the process of establishing a continuous ice cover - lasts from December to March. The thickness of the ice reaches 80-90 cm. Ice appears first in Taganrog Bay, then in Utlyuksky, Yeisk, Beysugsky And Akhtarsky estuary. Coastal parts Sea of ​​Azov And Taganrog Bay covered with continuous ice cover.

For Sea of ​​Azov characterized by a relatively short, but Cold winter. First frosts in Taganrog Bay on the northern coast they begin in October, and in the southern part of the sea - in the first half of November. In winter, temperatures can drop to -30°. Most low temperatures the upper layer of water is observed in the northern and eastern parts Sea of ​​Azov.

clickable

clickable

clickable

clickable

clickable

clickable

clickable

clickable

clickable

clickable

Sea water freezes at temperatures below zero degrees. The higher the salinity of sea water, the lower its freezing point. This can be seen from the following table:

This table shows that an increase in salinity of 2°/00 lowers the freezing point by about one tenth of a degree.

In order for water to begin to freeze oceanic salinity 35 °/ 00, it needs to be cooled below zero by almost two degrees.

Falling onto unfrozen fresh water river water, ordinary snow with a melting point of zero degrees, as a rule, melts. If this same snow falls on unfrozen sea water with a temperature of -1°, then it does not melt.

Knowing the salinity of the water, you can determine the freezing point of any sea using the table above.

The water salinity of the Sea of ​​Azov in winter is about 12 °/ 00; therefore, water begins to freeze only at a temperature of 0°.6 below zero.

In the open part White Sea salinity reaches 25 °/00. This means that for water to freeze, it must cool below minus 1°.4.

Water with a salinity of 100 °/00 (this salinity can be found in Sivashi, separated from the Sea of ​​Azov by the Arabat Spit) will freeze at a temperature of minus 6 °.1, and in Kara-Bogaz-Gol the salinity is more than 250 °/00, and the water only freezes when its temperature drops significantly below 10° below zero!

When salty sea ​​water cools to the appropriate freezing temperature, primary ice crystals begin to appear in it, in the form of very thin hexagonal prisms, similar to needles.

Therefore, they are usually called ice needles. Primary ice crystals that form in salty seawater do not contain salt; it remains in solution, increasing its salinity. This is easy to verify. After collecting the ice needles with a net made of very thin gauze or tulle, you need to rinse them fresh water to wash away salt water and then melt in another bowl. You will get fresh water.

Ice, as you know, is lighter than water, so ice needles float. Their accumulations on the surface of the water resemble appearance grease stains on cooled soup. These accumulations are called lard.

If the frost intensifies and the surface of the sea quickly loses heat, then the fat begins to freeze and in calm weather an even, smooth, transparent ice crust appears, which the Pomors, residents of our northern coast, call nilas. It is so pure and transparent that in huts made of snow, it can be used instead of glass (of course, if there is no heating inside such a hut). If you melt nilas, the water will turn out to be salty. True, its salinity will be lower than the water from which the ice needles were formed.

Individual ice needles do not contain salt, but salt appears in the sea ice formed from them. This happens because randomly located ice needles, freezing, capture tiny droplets of salty sea water. Thus, salt is distributed unevenly in sea ice - in separate inclusions.

Salinity sea ​​ice depends on the temperature at which it was formed. When there is slight frost, the ice needles freeze slowly and capture little salt water. In severe frost, ice needles freeze much faster and capture a lot of salt water. In this case, the sea ice will be saltier.

When sea ice begins to melt, the first thing that melts out of it is salty inclusions. Therefore, old, multi-year polar ice, which has flown over several times, becomes fresh. Polar winterers use for drinking water usually snow, and when there is no snow, old sea ice.

If during ice formation snowing, then it, without melting, remains on the surface of sea water, is saturated with it and, freezing, forms cloudy, whitish, opaque, uneven ice - young fish. Both nilas and youngsters, when wind and waves break, break into pieces, which, colliding with each other, hit the corners and gradually turn into round ice floes - blinks. When the excitement subsides, the pancakes freeze together, forming solid pancake ice.

Off the coast, in the shallows, sea water cools down faster, so ice appears earlier than in the open sea. Usually the ice freezes to the shores, this is fast ice. If frosts are accompanied by calm weather, fast ice grows quickly, sometimes reaching a width of many tens of kilometers. But strong winds and waves break the fast ice. The parts that come off from it float downstream and are carried away by the wind. This is how they arise floating ice. Depending on their size, they have different names.

An ice field is floating ice with an area greater than one square nautical mile.

Floating ice longer than one cable length is called ice field debris.

Coarse ice is shorter than one cable length, but more than one tenth of a cable length (18.5 m). Finely broken ice does not exceed one tenth of a cable length, and the ice porridge consists of small pieces tumbling on the waves.

Currents and wind can push ice floes against fast ice or against each other. The pressure of the ice fields on each other causes the fragmentation of floating ice. This usually creates piles of finely broken ice.

When a single ice floe rears up and in this position freezes into the surrounding ice, it forms a ropac. Ropacas covered with snow are difficult to see from an airplane and can cause a disaster during landing.

Often, under the pressure of ice fields, ice ridges are formed - hummocks. Sometimes hummocks reach a height of several tens of meters. Hummocky ice is difficult to pass, especially for dog sleds. It poses a serious obstacle even for powerful icebreakers.

A fragment of a hummock that rises above the surface of the water and is easily carried away by the wind is called a nesak. A fish that has run aground is called a stamukha.

Around Antarctica and in the North Arctic Ocean There are ice mountains - icebergs. These are usually fragments of continental ice.

In Antarctica, as researchers have recently established, icebergs also form in the sea, on the continental shallows. Only part of the iceberg is visible above the surface of the water. Most of it (about 7/8) is under water. The area of ​​the underwater part of the iceberg is always much larger than the surface area. Therefore, icebergs are dangerous for ships.

Now icebergs can be easily detected in the distance and in fog using precision radio instruments on a ship. Previously, there were cases of ship collisions with icebergs. This is how, for example, the huge ocean passenger steamer Titanic sank in 1912.

WATER CYCLE IN THE WORLD OCEAN

In the polar zones, water, as it cools, becomes denser and sinks to the bottom. From there it slowly slides towards the equator. Therefore, at all latitudes, deep waters are cold. Even near the equator, bottom waters have a temperature of only 1-2° above zero.

Since currents carry away from the equator warm water V temperate latitudes, then in its place from the depths it very slowly rises cold water. On the surface it warms up again, goes to the polar zones, where it cools, sinks to the bottom and moves along the bottom again to the equator.

Thus, in the oceans there is a kind of water cycle: on the surface water moves from the equator to the polar zones and along the bottom of the oceans - from the polar zones to the equator. This process of mixing water, along with other phenomena mentioned above, creates the unity of the World Ocean.

The water in the seas and oceans is very different from river and lake water. It is salty - and this determines many of its properties. The freezing temperature of sea water also depends on this factor. It is not equal to 0 °C, as is the case with fresh water. To become covered with ice, the sea requires stronger frost.

It is impossible to say unambiguously at what temperature sea water freezes, since this indicator depends on the degree of its salinity. It is different in different places of the world's oceans.

The saltiest is the Red Sea. Here the concentration of salt in the water reaches 41‰ (ppm). The waters of the Baltic Gulf have the least salt – 5‰. In the Black Sea this figure is 18‰, and in the Mediterranean – 26‰. The salinity of the Azov Sea is 12‰. And if we take it on average, the salinity of the seas is 34.7‰.

The higher the salinity, the more seawater must cool to become a solid.

This can be clearly seen from the table:

Where the salinity is even higher, such as in Lake Sivash (100 ‰), Kara-Bogaz-Gol Bay (250 ‰), in the Dead Sea (over 270 ‰), water can freeze only with a very large minus - in the first case - at -6.1 °C, in the second - below -10 °C.

The average for all seas can be taken as -1.9 °C.

Stages of freezing

It is very interesting to watch how sea water freezes. It is not immediately covered with a uniform ice crust, like fresh water. When part of it turns into ice (which is fresh), the rest becomes even more salty, and requires even stronger frost to freeze.

Types of ice

As the sea cools, different types of ice form:

• snowflake;
• sludge;
• needles;
• salo;
• nilas.

If the sea has not yet frozen, but is very close to it, and snow falls at this time, it does not melt upon contact with the surface, but is saturated with water and forms a viscous porridge-like mass, which is called snow. Freezing, this porridge turns into slush, which is very dangerous for ships caught in a storm. Because of it, the deck is instantly covered with an ice crust.

When the thermometer reaches the level required for freezing, ice needles begin to form in the sea - crystals in the form of very thin hexagonal prisms. Having collected them with a net, washed off the salt from them and melted them, you will find that they are fresh.

At first, the needles grow horizontally, then they take a vertical position, and only their bases are visible on the surface. They resemble spots of fat in cooled soup. Therefore, ice at this stage is called lard.

When it gets even colder, the lard begins to freeze and forms an ice crust, as transparent and fragile as glass. This type of ice is called nilas, or flask. It is salty, although formed from unleavened needles. The fact is that during freezing, the needles capture tiny drops of surrounding salt water.

Only in the seas is such a phenomenon known as floating ice observed. It occurs because the water here cools faster near the coast. The ice that forms there freezes to the coastal edge, which is why it is called fast ice. As frosts intensify during calm weather, it quickly captures new territories, sometimes reaching tens of kilometers in width. But it's worth the climb strong wind– and the fast ice begins to break into pieces of various sizes. These ice floes are often huge size(ice fields) are carried by wind and current throughout the sea, creating problems for ships.

Melting temperature

Sea ice does not melt at the same temperature at which sea water freezes, as one might think. It is less salty (on average 4 times), so its transformation back into liquid begins before this mark is reached. If the average freezing point of sea water is -1.9 °C, then the average melting temperature of the ice formed from it is -2.3 °C.

Salt water freezing: Video

If you look at the globe, you will also see a series of dotted horizontal lines. These lines divide earth's surface to different zones. The order of the zones is as follows.

Located around the equator tropical zone. It covers the Earth in a wide strip. Its borders are called the northern and southern tropics.

Temperate climate zones are located north and south of the tropics.

To the north and south of them are the polar regions. They occupy a position between 66.5 degrees to 90 degrees in the north and south.

Each zone has its own special climate, with its own characteristics.

So, West Side Europe is located a temperate zone, Here maritime climate. This means that in summer there is not much heat, and in winter it is too hot. severe frosts. In countries located near the sea (Belgium, England), water freezes very rarely due to the presence of the sea. Here in winter the water temperature in the sea is higher than on land. In summer, the opposite is true.

The eastern regions of Europe are more distant from the sea, and the climate here is continental. That's why it's not hot here in summer and colder in winter. That's why Northern part The Baltic Sea freezes in winter.

There is significantly less heat in the polar zone. Winter here lasts more than six months, and even in summer there is no heat. Therefore, the water in the polar seas does not have time to warm up well. Even in summer North Sea Ice floes and icebergs float.

For us, icebergs are wonderful objects to study and observe. But for ocean-going ships they pose a huge danger.

One of the most terrible maritime disasters occurred on the night of April 14, 1912, when the Titanic collided with an iceberg, killing 1,513 people.

An iceberg is a broken part of a glacier. This occurs when a glacier (which resembles a river of ice) moves down a valley and reaches the sea. The edge of the glacier breaks off and forms a floating iceberg.

Some icebergs appear in fiords - narrow bays with high steep walls, from where they emerge into the oceans. The edges of some icebergs are broken or smoothed by waves. A significant underwater part of them remains under the surface of the water, which occasionally breaks off and unexpectedly floats to the surface in the form of icebergs.

Icebergs vary in size. Small ones, 5-10 meters in diameter, are called “growlers” by sailors. But icebergs with a diameter of more than 100 meters are more common. Some ice mountains reach 1000 meters in diameter.

The density of an iceberg is about 90% that of water, so only one-ninth of this ice mountain is above the surface, and eight-ninths is hidden under water. Therefore, an ice floe 45 meters high above the surface of the water goes 200 meters deep. It is difficult to imagine how much ice such a mountain contains. After all, some of them weigh 180,000,000 tons.

Since the main part of the iceberg is under water, its movement is influenced not by the wind, but by sea ​​currents. Icebergs gradually reach warm latitudes, where they melt. Only a few of them reach warm current Gulf Stream, east of Newfoundland in Canada. They pose the greatest danger to ships. Therefore, the Coast Guard in the United States constantly monitors the appearance of icebergs, warning ships about the location of these ice mountains.

Severe frosts also reached the Black Sea coast. In the areas of Kerch, Evpatoria, and Odessa, the water turned to ice. On the beaches, crumbs of ice float in the water, and small icebergs can be seen 100 meters from the shore.

Due to the current situation it is closed until February 15th sea ​​communication in Ukrainian ports. The Romanian port of Constanta is closed, and ice thickness on the beaches reaches 40 centimeters. Both Romania and Bulgaria announced a “yellow” and “orange” danger code.

However, the inhabitants of these countries do not despair: they use frozen water as an ice skating rink, and build sculptures from ice and snow. IN last time such weather anomalies took place in 1977, when the Black Sea off the coast of Odessa completely froze.

(Total 16 photos)

Post sponsor: Buy adena on asterios: You can buy adena on asterios right away. This way you will show the already “experienced” players that you are serious and decisive. Having learned about this, they will be more willing to help you and advise you on many necessary things.

1. Bad weather hit the Black Sea coast. In the photo: The frozen Black Sea near Constanta, Romania. (Vadim Ghirda/AP Photo)

2. Crushed ice floats near the beaches, and small icebergs can be seen 100 meters from land. The waves prevent the sea from completely covering with a dense crust. (Vadim Ghirda/AP Photo)

3. The surface of the sea in the Evpatoria area began to become covered with ice. Freezing area - approximately two thousand square meters. In the photo: Ice-covered pier in Evpatoria. (Stringer/Reuters)

4. In the areas of Kerch, Evpatoria, Odessa, water turned into ice, which is observed for the first time in 30 years. (Vadim Ghirda/AP Photo)

5. Seagulls against the backdrop of ice blocks in Constanta. (Vadim Ghirda/AP Photo)

6. Because weather conditions Sea traffic in Ukrainian ports is closed until February 15. (Vadim Ghirda/AP Photo)

7. People walk on the frozen Black Sea next to an ice-covered dam in Constanta, Romania. (Daniel Mihailescu/AFP/Getty Images)

8. The Romanian port of Constanta is also closed; on the beaches the ice thickness reaches 40 centimeters.

9. Both Romania and Bulgaria announced a “yellow” and “orange” danger code.

10. An icy ship off the coast of Evpatoria. (Alexey Pavlishak/ITAR-TASS)

11. Frozen Black Sea near Constanta, Romania. (Vadim Ghirda/AP Photo)

12. The frozen Black Sea off the coast of Evpatoria. (Alexey Pavlishak/ITAR-TASS)15. Ice formed in calm weather conditions blocks ships. (Vadim Ghirda/AP Photo)

16. A ship in the ice of the Black Sea off the coast of Constanta. (Vadim Ghirda/AP Photo)