At what temperature does salty sea water freeze. Freezing of sea water

Young naturalists are always haunted by seemingly simple questions. At what temperature does sea water usually freeze? Everyone knows that zero degrees is not enough to turn the sea surface into a good ice rink. But at what temperature does it happen?

What is seawater made of?

How is the content of the seas different from fresh water? The difference is not that great, but still:

Much more salt.
Magnesium and sodium salts prevail.
The density differs slightly, within a few percent.
Hydrogen sulfide may form at depth.

The main component of sea water, however predictable it may sound, is water. But unlike the water of rivers and lakes, in it contains a large number of sodium and magnesium chlorides.

The salinity is estimated at 3.5 ppm, but to make it more clear - at 3.5 thousandths of a percent of the total composition.

And even this, not the most impressive figure, provides water not only with a specific taste, but also makes it unsuitable for drinking. There are no absolute contraindications, sea water is not a poison or toxic substance and nothing terrible will happen from a couple of sips. It will be possible to talk about the consequences if a person is at least during the day. Also, the composition of sea water includes:

Fluorine.
Bromine.
Calcium.
Potassium.
Chlorine.
Sulfates.
Gold.

True, the percentage of all these elements is much less than salts.

Why not drink sea water?

We have already touched on this topic in passing, let's look at it in more detail. Together with sea \u200b\u200bwater two ions enter the body - magnesium and sodium.

Sodium	Magnesium
Participates in maintaining the water-salt balance, one of the main ions along with potassium.	The main effect is on the central nervous system.
With an increase in the number Na in the blood, fluid is released from the cells.	It is excreted very slowly from the body.
All biological and biochemical processes are disrupted.	An excess in the body leads to diarrhea, which aggravates dehydration.
The human kidneys are unable to handle this amount of salt in the body.	Development possible nervous disorders, inadequate condition.

This is not to say that a person does not need all these substances, but needs always fit into certain frameworks. After drinking a few liters of such water, you will go too far beyond them.

However, today the acute need for the use of sea water may arise only from the victims of shipwrecks.

What determines the salinity of sea water?

Seeing just above the figure 3.5 ppm , you might think that this is a constant for any sea water on our planet. But it's not that simple, the salinity depends on the region. It just so happened that the further north the region is located, the greater this value.

On the contrary, the south can boast of not so much salty seas and the oceans. Of course, there are exceptions to all the rules. The salt levels in the seas are usually slightly lower than in the oceans.

What could be the reason for the geographical division? It is not known, researchers take it for granted, there is everything. Perhaps the answer should be sought in the earlier periods of the development of our planet. Not at the time when life was born - much earlier.

We already know that the salinity of water depends on the presence in it:

Magnesium chlorides.
Sodium chlorides.
Other salts.

Perhaps, in some parts of the earth's crust, the deposits of these substances were somewhat larger than in neighboring regions. On the other hand, no one canceled the sea currents, sooner or later general level should have leveled off.

So most likely the slight difference is due to climatic features our planet. Not the most unfounded opinion, if you remember about frost and consider what exactly water with a high salt content freezes more slowly.

Desalination of sea water.

With regard to desalination, everyone has heard at least a little, some now even the film “ Water world"Will remember. How realistic is it to put one such portable watermaker in each house and forget about the problem for humanity forever? drinking water? Still fiction, not a reality that has come.

It's all about the energy expended, because for effective work, huge powers are needed, no less nuclear reactor... A desalination plant in Kazakhstan operates on this principle. The idea was also submitted in Crimea, but the power of the Sevastopol reactor was not enough for such volumes.

Half a century ago, before numerous nuclear disasters, it was still possible to assume that a peaceful atom would enter every home. Even the slogan was. But it is already clear that there is no use of nuclear micro-reactors:

In household appliances.
In industrial plants.
In the structures of cars and aircraft.
And in general, within the city limits.

The next century is not expected. Science can make another leap and surprise us, but so far it's all just the fantasies and hopes of reckless romantics.

At what temperature can sea water freeze?

But the main question has not yet been answered. We have already learned that salt slows down the freezing of water, and the sea comes out with a crust of ice not at zero, but at sub-zero temperatures. But how far should the thermometer readings go to minus so that, leaving their homes, residents of coastal areas do not hear the usual sound of the surf?

To determine this value, there is a special formula that is complex and understandable only for specialists. It depends on the main indicator - salinity level... But since we have an average for this indicator, can we and average temperature freezing to find? Yes of course.

If you do not need to calculate everything up to the hundredth, for a specific region, remember the temperature at -1.91 degrees.

It may seem that the difference is not that great, only two degrees. But during seasonal temperature fluctuations, this can play a huge role where the thermometer drops at least 0. It would be only 2 degrees cooler, the inhabitants of the same Africa or South America could see the ice near the coast, and so - alas. However, we do not think that they are greatly upset by such a loss.

A few words about the world's oceans.

And what about the oceans, fresh water supplies, and the level of pollution? Let's try to find out:

The oceans are still standing, nothing has happened to them. In recent decades, the water level has been rising. Perhaps this is a cyclical phenomenon, or maybe the glaciers are melting.
Fresh water is also more than enough, it is too early to raise a panic about this. If there is another global conflict, this time with the use of nuclear weapons, maybe we will, like in "Mad Max", pray for saving moisture.
The last point is very much loved by conservationists. And sponsoring is not so difficult to achieve, competitors will always pay for black PR, especially when it comes to oil companies. But it is they who cause the main damage to the waters of the seas and oceans. It is not always possible to control oil production and emergency situations, and the consequences are catastrophic every time.

But the world's oceans have one advantage over humanity. It is constantly being updated, and its real self-cleaning capabilities are very difficult to assess. Most likely, he will be able to survive human civilization and see its decline in a perfectly acceptable state. Well, then the water will have billions of years to cleanse itself of all the "gifts".

It is even difficult to imagine who needs to know at what temperature sea water freezes. A general educational fact, but who will really use it in practice is a question.

Video experiment: freezing seawater

IN Kerch Strait - complex unstable ice regime... He carried out engineering surveys in this regard. Decrease in temperature at east and northeasterly winds creates in winter period conditions for ice formation in the strait. In the open part Sea of \u200b\u200bAzov and in the northern part Kerch Strait complete freezing is observed only in severe winters. The final clearing of ice in such cases occurs on average by February 28, although after severe winters on the approach to the Kerch Strait, a meeting with ice is possible in mid-April.

clickable

In the alignment of the bridge, the presence of both weakened ice and solid ice is possible. So in harsh winters, bridge piers can be exposed to different types of ice impacts - from moving ice from Sea of \u200b\u200bAzov, hummocks, movement of the ice field and thermal expansion of ice. When calculating ice loads on bridge piers, these factors were carefully studied.

Based on the results of model studies carried out in conditions of continuous flat ice, broken ice and hummocks, the values \u200b\u200bof the five components of the global ice load were obtained for different depths of the water area, as well as the velocities and directions of ice drift. All this was taken into account when developing final design solutions.

There are rather large spans between the supports, so, most likely, additional funds will not be required to clear the water area. To control ice conditions during the freeze-up period, ice conditions monitoring is organized. If necessary, icebreaker-type vessels located in the port of Novorossiysk are ready to arrive within 8-10 hours to crush ice fields.

Azov sea freezes every year. It is common for ice to appear and melt repeatedly over the course of one season. In the midst of winter, ice can cover the entire water area Sea of \u200b\u200bAzov and form an almost continuous fast ice - a stationary ice mass along the coast. Early 2017 Azov sea almost completely frozen.
Azov sea - the shallowest and most distant sea in the world. Its average depth is about 7 meters, the deepest sections reach 13.5 meters. To imagine how shallow the sea is, it is enough to compare it with By the black sea, the average depth of which is 1`240 meters.

Photos Kiziltashsky and Bugaz estuaries near the village of Blagoveshchenskaya and the site Sea of \u200b\u200bAzov near village Golubitskaya and village Peresyp made by Alexey Shkolny in mid-February 2017.

Water Sea of \u200b\u200bAzov contains three times less salt than World Ocean average. In critical situations, it can even quench your thirst. A low volume of salt is formed due to the abundant inflow of river waters: up to 12% of the volume of water enters Azov from the rivers. Another factor is the difficult water exchange with By the black sea... Due to the low salinity, the sea freezes easily.

Every year when the water temperature drops below zero, Azov sea covered with ice. Freezing-up - the process of establishing a continuous ice cover - lasts from December to March. The thickness of the ice reaches 80-90 cm. First of all, ice appears in Taganrog Baythen in Utlyuk, Yeisk, Beysugsky and Akhtarsk estuary... Onshore parts Sea of \u200b\u200bAzov and Taganrog Bay covered with a continuous ice cover.

For Sea of \u200b\u200bAzov characterized by a relatively short, but cold winter... The first frosts in Taganrog Bay on the northern coast they come in October, and in the southern part of the sea in the first half of November. In winter, temperatures can drop to -30 °. The lowest temperatures of the upper layer of water are observed in the northern and eastern parts. Sea of \u200b\u200bAzov.

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Ice sheet in the Black Sea is often formed only on the northern shores, and then in relatively severe winters. Ice usually does not appear on the Caucasian and Anatolian coasts. Almost every year, the Dnieper-Bug and Dnestrovsky estuaries, lakes near the Danube delta and on the north-western coast freeze. In very cold winters, the Danube River is held down by ice, and in some cases, the coastal strip of the sea. During the period of ice drift, the current carries the ice to the south to the Bulgarian shores; usually they reach "Cape Kaliakra, and in rare cases they descend to the south. In extremely severe winters, when the sea freezes off the Bulgarian coast, broken ice carries even to the Bosphorus and Eregli.

On the Crimean coast, ice usually forms up to Cape Tarkhankut, and broken ice reaches Yevpatoria. Ice removed from the Sea of \u200b\u200bAzov often appears near the Kerch Strait and reaches Anapa in the eastern direction, in the western direction - to Feodosia.

Herodotus gives the first information about freezing up on the Black Sea; he mentions that the Cimmerian Bosphorus (Kerch Strait) and Meotida (Sea of \u200b\u200bAzov) are often covered with a fairly thick layer of ice, which, breaking in spring, is carried out to the Pontus (Black Sea). The Roman poet Ovid, exiled to Lesser Scythia (Dobrudzha), writes that from 7 to 17 for three winters, the Danube and coastal sea waters froze over a considerable length. Frequent freezing conditions on the Danube are reported by Nolian (III century). Significant freezing of the Black Sea observed in 401, Amianus Marceline writes that almost the entire sea froze, in the spring ice fields filled the Bosphorus, and from it they went to the Sea of \u200b\u200bMarmara and swam there for about a month. Byzantine sources mention the freezing of the Bosphorus in 739, 753 and 755. In 755, ice formed in the Sea of \u200b\u200bMarmara and clogged the Dardanelles.

The most intense ice formation, in 762, is reported by the patriarch Nikifor and the chronicler Codrin: about 100 miles from the land, the Black Sea froze over, even in the Anatolian coast. From Messembriya (Nessebar) it was possible to walk along the ice to the Caucasian coast.

Freeze up in the Bosphorus was noted in 928 and 934. In 1011, not only the Bosphorus froze, but also part of the Sea of \u200b\u200bMarmara. At the same time, great cold weather came in Syria and Egypt, ice appeared in downstream the Nile River. The northern part of the Black Sea froze over, according to the testimony of Prince Gleb Svyatoslavich, in 1068.

Ice appeared near the southern shores of the Black Sea and in the Bosphorus and in 1232, 1621, 1669 and 1755. In 1813, the Black Sea was covered with ice from the northern shores to the southern regions of the Crimea. The Bosphorus froze in 1823, 1849 and 1862.

In 1929, 1942 and 1954. ice formed almost along the entire Bulgarian coast, at the same time ice penetrated into the Bosphorus. Freezing up in the northwestern part of the Black Sea and in the Sea of \u200b\u200bAzov and a strong ice drift on the Danube in 1972 caused the appearance of ice fields near the Bulgarian coast even south of Cape Kaliakra. But sustained winds from land carried them to the open sea.

The appearance of ice and sludge in the shallow parts of the bays of the Bulgarian coast was also observed in other years. Lakes located near the sea coast freeze more often.

Ice formed from sea water contains less salt than the water contained. In education sea \u200b\u200bice between ice crystals, consisting of pure water, small drops of sea water (brine) are retained. Over time, the brine ste

ice falls down, the ice is desalinated, and air bubbles appear in it, creating its porosity.

Fresh water freeze at 0 ° C, salty - at more low temperatures... In the oceans, water freezes at temperatures from -1.9 to -2 ° C, in the Black Sea - at a temperature of -0.9 ° C, but only in calm weather. With strong waves in the water, ice crystals form - ice porridge, while the water temperature can be about -1.1 or -1.2 ° C.

The salinity of the bottom of the ice immersed in water is higher than that of the top, even in freshwater icecaught in the sea, the lower part is saturated with sea water.

Salinity upper layers sea \u200b\u200bice is negligible. With aging ice chemical composition it changes - the amount of chlorides decreases and the amount of bicarbonates increases.

In general, ice cover contains significantly less salt than sea water.

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

Closed until February 15 due to the current situation sea \u200b\u200btraffic in Ukrainian ports. The Romanian port of Constanta is closed; on the shores of the beaches, the ice thickness reaches 40 centimeters. Both Romania and Bulgaria have declared "yellow" and "orange" hazard codes.

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

Photo: Frozen Black Sea near Constanta, Romania

Ice-covered ship off the coast of Evpatoria.
http://bigpicture.ru/?p\u003d254667

01.03.2011
According to the Hydrometeorological Center of the Black and Azov Seas. - “This winter was distinguished by sharp and prolonged cold weather, which led to the freezing of water near the coast. This phenomenon is extremely rare. Last time off the coast of Odessa the sea was completely frozen in 1977 ”.

For the third time since the beginning of winter, the Sea of \u200b\u200bAzov also froze over. The thickness of the ice in a number of places reaches 20 cm, ice blocks up to 5-10 m high have been nailed to the village of Sedovo in the Novoazovsky district, which lined up along the entire coastal strip. because of strong wind the ferry flights from Crimea to Russia are temporarily limited.

The thickness of the ice in the coastal zone is about 20 cm. It can easily support the weight of an adult, but there are no people who want to walk on the ice in such weather.

Well, if 1977 is still preserved in the memory of old-timers, then archival and literary sources say that over the past two millennia in the Black Sea region there have been more than 20 "cruel" winters with an average interval of 78 years (from 60 to 90 years ). The first information about an unusually harsh winter, in particular that the Black Sea was partially frozen, is found in the letters of Ovid, a poet of ancient times, exiled at the beginning of the 1st century. BC e. in the lower reaches of the Danube. Ovid writes: "... Istria (Danube) became three times from the cold, and the sea wave hardened three times."

There are others more late posts about the unusual cold in the Black Sea region. So, for example, in the winter of 400-401. “... for 20 days the straits of the Bosphorus and Dardanelles and most of the Black Sea were frozen. In the spring ice went mountains in the streets of Constantinople for 30 days. "

In the winter of 557-558. "... the Black Sea was covered with ice over a large area."
Byzantine, Arab and Western European chronicles indicate that in 763-764. “... winter is fierce. From the beginning of October, there was a great severe cold not only in our land (Byzantium), but also in the east, north, west, so that the northern part of the Pontic (Black) Sea, 100 miles from the coast, turned to stone ... And the same happened from Zikhia (Taman Peninsula) to the Danube, from the Kufis River (Kuban) to the Dniester and the Dnieper, from all other banks to the Media. When the snow fell on such thick ice, its thickness increased even more, and the sea took the form of land. And they walked along it like dry land from Crimea to Thrace and from Constantinople to Skutari. "

The winter of 1233-1234 was extremely fierce throughout the Mediterranean. According to the testimony of Arago, "... loaded carts moved on the ice across the Adriatic Sea near Venice." Several other authors confirm that many lagoons of the Mediterranean and the northern part of the Black Sea were frozen.
Two hundred years before that in 1010 - 1011. frosts bound the present Turkish Black Sea coast. Terrible cold reached Africa (!), The lower reaches of the Nile were frozen with ice.

Winter 1543-1544 was also extremely cold for many european countries - Germany, France, the countries of the Northern Black Sea region. The north of the Black Sea was covered with ice. In France there were such frosts that they had to "chop" the wine frozen in large barrels.

In the chronicles of 1708-1709 we read: "... An unusually harsh, snowy and long winter throughout Europe", the bays of the Adriatic Sea completely froze, in Venice the air temperature dropped to -20C, "many thousands of people died from the cold, orange trees cracked ". In the same year, winter was unusually cold in France and Switzerland, strong freeze-up was observed on the Thames, Seine, and Rhone. In the Baltic Sea, the ice thickness reached 80 cm.

At the end of the eighteenth century. in Russia "there were great snows and a heavy winter with frosts, from which the Swedes died a lot", the northern part of the Black Sea froze over. The chroniclers call the winter of 1788-1789 "great". All over Europe there were severe cold weather: in France (-21C), in Italy (-15C), "severe frosts and snowfalls" in Switzerland, cold weather in Germany, the Vistula froze a month earlier and opened a month later than usual. In the Crimea, frosts reached -25C - in the Northern Black Sea region, "the winter is severe, full of frosts, from the huts they crawled out through the roofs because of the great snows", the northern part of the Black Sea froze.

Exceptionally harsh, long and snowy in Central and Eastern Europe it was winter 1875-1876. In the mountains of Switzerland, the number of snow avalanches... Almost all southern rivers were covered with ice much earlier than usual, catastrophic drifts were observed on the Caucasian roads, and the Black Sea froze again.

The most harsh winter XX century the winter of 1953-1954 is considered. Fierce, unprecedented cold weather from November to April was on the vast territory from Spain and France to the Ural ridge. On South Bank Crimea frosts kept for three months in a row, average monthly temperature February was 10-12C lower than normal, in Yalta the depth of the snow cover exceeded 30 cm, in the Caspian Sea floating ice reached the Absheron Peninsula. The Sea of \u200b\u200bAzov was completely frozen, a stable road connection was opened through the Kerch Strait, the northern part of the Black Sea was frozen.

By the way, the winter of 1962-1963 was remembered by the searing frosts and fierce snowstorms. Ice bound the usually non-freezing Danish Strait, and the canals of Venice and the rivers of France froze again. The 1968-1969 season is also called "the winter of violent frosts".

In 2002, due to frosts in Germany, the movement of ships along the Main-Danube Canal, which is an important European water transport artery, was completely stopped. The thickness of the ice, into which more than 20 ships were frozen, reached 70 cm in places.

Then, due to severe cold weather, the Venice lagoon froze over, gondolas froze into the ice. The same frosts were in Venice in 1985.

At the end of 2005, most countries in Central and Western Europe also found themselves at the mercy of heavy snowfalls. In Germany and the Netherlands, cold weather, unusual for this time of year, led to icing and broken power lines. In Paris, due to icing, the Eiffel Tower, the main attraction of France, was closed for several hours.

As for the current situation, according to forecasters, ice in the coastal zone of the Sea of \u200b\u200bAzov will last until the second decade of March. In the Odessa region, the sea will be cleared in the coming days.