Who discovered the Baltic Sea. Baltic Sea: salinity, depth, coordinates and interesting facts

BALTIC SEA (late Latin - Mare Balticum, among the ancient Slavs - Varangian Sea or Sveiskoe), inland sea Atlantic Ocean, between the Scandinavian Peninsula and the mainland shores of Northwestern Europe. It washes the shores of Sweden, Finland, Russia, Estonia, Latvia, Lithuania, Poland, Germany, Denmark. In the southwest it is connected to the North Sea by the Danish Straits. Sea border Baltic Sea passes along the southern entrances of the Oresund, Great Belt and Little Belt straits. Area 419 thousand km 2, volume 21.5 thousand km 3. Greatest depth 470 m. Depths above the rapids of the Danish Straits: Darser - 18 m, Drogden - 7 m. The cross section above the rapids is 0.225 and 0.08 km 2, respectively, which limits water exchange with the North Sea. The Baltic Sea juts deep into the Eurasian continent. The heavily indented coastline forms numerous bays and bays. The largest bays are: the Gulf of Bothnia, the Gulf of Finland, the Gulf of Riga, the Curonian Lagoon, the Szczecin Bay, the Gulf of Gdansk. The shores of the Baltic Sea in the north are high, rocky, mainly of skerry and fjord types, in the south and southeast they are mostly low-lying, lagoon-type, with sandy and pebble beaches. The largest islands: Gotland, Bornholm, Saaremaa, Muhu, Hiiumaa, Öland, Rügen. There are many small rocky islands - skerries, located along the northern shores (there are over 6 thousand in the Åland group of islands).

Relief and geological structure bottom. The Baltic Sea is shallow, lies entirely within the shelf, depths up to 200 m occupy 99.8% of its area. The shallowest waters are the Gulf of Finland, the Gulf of Bothnia and the Gulf of Riga. These areas of the bottom have a leveled accumulative topography and a well-developed cover of loose sediments. Most of the bottom of the Baltic Sea is characterized by highly dissected relief. The bottom of its basin has depressions delimited by hills and the bases of islands: in the west - Bornholm (105 m) and Arkon (53 m), in the center - Gotland (249 m) and Gdansk (116 m); to the north of the island of Gotland, the deepest depression, the Landsort depression (up to 470 m), stretches from northeast to southwest. Numerous stone ridges, in the central part of the sea ledges are traced - continuations of cliffs stretching from the northern coast of Estonia to the northern tip of the island of Öland, underwater valleys, glacial-accumulative landforms flooded by the sea.

The Baltic Sea occupies a depression in the west of the ancient East European Platform. The northern part of the sea is located on the southern slope of the Baltic Shield; the central and southern parts belong to a large negative structure of the ancient platform - the Baltic syneclise. The extreme southwestern part of the sea is part of the young Western European Platform. The bottom in the north of the Baltic Sea is composed mainly of complexes of Precambrian age, overlain by an intermittent cover of glacial and modern marine sediments. In the central part of the sea, Silurian and Devonian sediments take part in the structure of the bottom. The ledges traced here are formed by Cambrian-Ordovician and Silurian rocks. Paleozoic complexes in the south are overlain by thick layers of glacial and marine sediments.

During the last ice age (late Pleistocene), the Baltic Sea basin was completely blocked by an ice sheet, after the melting of which the Baltic Glacial Lake was formed. At the end of the Late Pleistocene, about 13 thousand years ago, the lake connected with the ocean, and the depression was filled with sea water. The connection with the ocean was interrupted in the interval 9-7.5 thousand years ago, after which a marine transgression followed, the deposits of which are known on the modern coast of the Baltic Sea. In the northern part of the Baltic Sea, the rise continues, the speed of which reaches 1 cm per year.

Bottom sediments at depths of over 80 m are represented by clayey silts, under which lies banded clay on glacial deposits; at shallower depths, silt is mixed with sand; sand is common in coastal areas. There are boulders of glacial origin.

Climate. The Baltic Sea is characterized by a temperate maritime climate with continental features. Its seasonal features are determined by the interaction of pressure centers: the Icelandic minimum and the Azores maximum in the west and the Siberian maximum in the east. Cyclonic activity reaches its greatest intensity in the autumn-winter months, when cyclones bring cloudy, rainy weather with strong western and southwestern winds. The average air temperature in February ranges from -1.1°C in the south, -3°C in the central part of the sea, to -8°C in the north and east, in the northern part of the Gulf of Bothnia to -10°C. Rarely and a short time The cold arctic air penetrating the Baltic lowers the temperature to -35°C. In summer, westerly winds also blow, but small force, bringing cool, wet weather from the Atlantic. The air temperature in July is 14-15°C in the Gulf of Bothnia and 16-18°C in other areas of the sea. Rare arrivals of warm Mediterranean air cause short-term increases in temperature to 22-24°C. The annual precipitation ranges from 400 mm in the north to 800 mm in the south. Largest number days with fog (up to 59 days a year) are observed in the south and central part of the Baltic Sea, the smallest (22 days a year) - in the north of the Gulf of Bothnia.

Hydrological regime. The hydrological conditions of the Baltic Sea are determined by its climate, significant influx of fresh water and limited water exchange with the North Sea. About 250 rivers flow into the Baltic Sea. The average river flow is 472 km 3 per year. The largest rivers are: Neva - 83.5 km 3, Vistula - 30, Neman - 21, Western Dvina - 20 km 3 per year. Freshwater flow is distributed unevenly across the territory. The Gulf of Bothnia receives 181, the Gulf of Finland - 110, the Gulf of Riga - 37, and the central part of the Baltic Sea - 112 km 3 per year. The amount of fresh water coming from precipitation(172 km 3 per year), equal to evaporation. Water exchange with the North Sea averages 1,660 km 3 per year. Fresher waters with a surface runoff flow leave the Baltic Sea into the North Sea, salty North Sea water with a bottom current flows through the straits from North Sea. Strong westerly winds usually increase the inflow, while eastern winds increase the outflow of water from the Baltic Sea through the Danish Straits.

The hydrological structure of the Baltic Sea in most areas is represented by surface and deep water masses, separated by a thin intermediate layer. The surface water mass occupies a layer from 20 to (in some places) 90 m, its temperature throughout the year ranges from 0 to 20 ° C, salinity is usually within 7-8‰. This water mass is formed in the sea itself as a result of the interaction of sea waters with fresh waters atmospheric precipitation and river flow. It has winter and summer modifications, differing mainly in temperature. In the warm season, the presence of a cold intermediate layer is noted, which is associated with the summer heating of water on the surface. The deep water mass occupies a layer from 50-100 m to the bottom, its temperature varies from 1 to 15 ° C, salinity - from 10.0 to 18.5‰. Deep water is formed in the bottom layer as a result of mixing with high salinity water coming from the North Sea. Renewal and ventilation of bottom waters strongly depend on the flow of north sea ​​water, which is subject to interannual variability. With a reduction in the influx of salt water into the Baltic Sea at great depths and in depressions in the bottom topography, conditions are created for the occurrence of dead water phenomena. Seasonal changes in water temperature affect the layer from the surface to 50-60 m and usually do not penetrate deeper.

Wind waves develop especially strongly in the autumn winter time during prolonged and strong southwestern winds, when waves 5-6 m high and 50-70 m long are observed. The highest waves are observed in November. In winter, sea ice prevents the development of waves.

In the Baltic Sea, cyclonic (counterclockwise) water circulation, complicated by vortex formations of different scales, can be traced everywhere. The speed of constant currents is usually about 3-4 cm/s, but in some areas they sometimes increase to 10-15 cm/s. Due to low speeds, currents are unstable, their pattern is often disrupted by winds. Storm winds cause strong wind currents with speeds of up to 150 cm/s, which quickly fade after the storm.

The tides in the Baltic Sea, due to the insignificant connection with the ocean, are weakly expressed, the height is 0.1-0.2 m. Surge level fluctuations reach significant values ​​(at the tops of the bays up to 2 m). Combined effects of wind and sudden changes atmospheric pressure cause seiche level fluctuations with a period of 24-26 hours. The magnitude of such fluctuations ranges from 0.3 m in the open sea to 1.5 m in the Gulf of Finland. Seiche waves with surge westerly winds sometimes cause the level at the top of the Gulf of Finland to rise to 3-4 m, which delays the flow of the Neva and leads to floods in St. Petersburg, sometimes catastrophic: in November 1824 about 410 cm, in September 1924 - 369 cm.

The surface water temperature of the Baltic Sea varies greatly from season to season. In August, in the Gulf of Finland the water warms up to 15-17°C, in the Gulf of Bothnia 9-13°C, in the central part of the sea 14-18°C, in the southern regions it reaches 20°C. In February, in the open part of the sea, the surface water temperature is 1-3°C, in bays and bays it is below 0°C. The salinity of water on the surface is 11‰ at the exit from the Danish Straits, 6-8‰ in the central part of the sea, 2‰ and less at the tops of the Gulf of Bothnia and the Gulf of Finland.

The Baltic Sea belongs to the so-called brackish basins, in which the temperature of the highest density is above the freezing point, which leads to the intensification of the formation process sea ​​ice. Ice formation begins in November in bays and off the coast, and later in the open sea. In severe winters, the ice cover occupies the entire northern part of the sea and coastal waters its central and southern parts. The thickness of fast ice (fixed ice) reaches 1 m, drifting ice - from 0.4 to 0.6 m. Ice melting begins at the end of March, spreads from southwest to northeast and ends in June.

History of the study. The first information about the exploration of the Baltic Sea is associated with the Normans. In the middle of the 7th century, they penetrated into the Gulf of Bothnia, discovered the Åland Islands, in the 2nd half of the 7th-8th centuries they reached the western coast of the Baltic States, discovered the Moonsund Archipelago, for the first time penetrated the Gulf of Riga, in the 9th-10th centuries they used the coast for trade and pirate activities from the mouth of the Neva to the Gdansk Bay. Russian hydrographic and cartographic work began in the Gulf of Finland at the beginning of the 18th century. In 1738, F.I. Soimonov published an atlas of the Baltic Sea, compiled from Russian and foreign sources. In the middle of the 18th century, many years of research were carried out by A.I. Nagaev, who compiled a detailed sailing guide for the Baltic Sea. The first deep-sea hydrological studies in the mid-1880s were carried out by S. O. Makarov. Since 1920, hydrological work has been carried out by the Hydrographic Administration navy, State Hydrological Institute (Leningrad), and from the 2nd half of the 20th century, extensive comprehensive research was launched under the leadership of the Leningrad (St. Petersburg) branch of the State Oceanographic Institute of the Russian Academy of Sciences.

Economic use. Fish resources consist of freshwater species, living in the desalinated waters of the bays (crucian carp, bream, pike, pike perch, chub), the Baltic herd of salmon and pure marine species, distributed mainly in the central part of the sea (cod, herring, smelt, vendace, sprat). In the Baltic Sea there is fishing for herring, sprat, herring, smelt, river flounder, cod, perch, etc. Unique object fishery - eel. Placers of amber are widespread on the coast of the Baltic Sea; mining is carried out near Kaliningrad (Russia). Oil reserves were discovered at the bottom of the sea, and industrial development began. Iron ore is mined off the coast of Finland. The Baltic Sea is of great importance as a transport artery. Large volumes of liquid, bulk and general cargo are transported across the Baltic Sea. A significant part of the foreign trade of Denmark, Germany, Poland, Russia, Lithuania, Latvia, Estonia, Finland, and Sweden is carried out through the Baltic Sea.

The cargo turnover is dominated by oil products (from Russian ports and from the Atlantic Ocean), coal (from Poland, Russia), timber (from Finland, Sweden, Russia), pulp and paper (from Sweden and Finland), iron ore (from Sweden); machines and equipment also play an important role, major manufacturers and whose consumers are countries located on the shores and in the Baltic Sea basin. The largest ports of the Baltic Sea: St. Petersburg, Kaliningrad (Russia), Tallinn (Estonia), Riga (Latvia), Gdansk, Gdynia, Szczecin (Poland), Rostock - Warnemünde, Lübeck, Kiel (Germany), Copenhagen (Denmark), Malmö , Stockholm, Luleå (Sweden), Turku, Helsinki, Kotka (Finland). In the Baltic Sea there are sea passenger and ferry connections: Copenhagen - Malmö, Trelleborg - Sassnitz (train ferries), Nortelje - Turku (car ferry), etc. There are many resort places on the southern and south-eastern coasts.

Ecological state. The Baltic Sea, which has difficult water exchange with the World Ocean (water renewal lasts about 30 years), is surrounded by industrial developed countries and is experiencing extremely intense anthropogenic pressure. The main environmental problems are associated with burial at the bottom of the sea chemical weapons, dumped into the sea Wastewater large cities, the run-off of chemical fertilizers used in agriculture, and especially shipping traffic - one of the most intense in the world (mainly oil tankers). Since the entry into force of the Convention for the Protection of marine environment Baltic Sea ecological situation improved due to the commissioning of a large number of wastewater treatment plants, reducing the use of chemical fertilizers, controlling technical condition ships. The concentration of toxic substances such as DDT and polychlorinated biphenyl, petroleum carbons has decreased. The dioxin content in Baltic herring is 3 times lower than the maximum permissible concentration, and the gray seal population has recovered. The issue of giving the Baltic Sea the status of a particularly vulnerable sea area is being considered.

Lit.: Terms. Concepts. Reference tables. M., 1980; Hydrometeorological conditions of the shelf zone of the USSR seas. L., 1983. T. 1. Issue. 1: Baltic Sea without bays; Atlantic Ocean. L., 1984; Biological resources of the Atlantic Ocean. M., 1986; Pushcharovsky Yu. M. Tectonics of the Atlantic with elements of nonlinear geodynamics. M., 1994; Hydrometeorology and hydrochemistry of the seas of the USSR. St. Petersburg, 1994. T. 3. Issue. 2; Zalogin B.S., Kosarev A.N. Seas. M., 1999.

The Baltic Sea, like a real European one, washes the borders of several states at once. If previously many principalities and empires fought for the right to own the ports located on it, today the situation in the water area is calm. Nine countries have access to the shores of the Baltic Sea: Russia, Estonia, Lithuania, Latvia, Poland, Denmark, Sweden, Germany and Finland.

The Baltic Sea can be called a typical inland sea. It is located in the Northwestern part of Eurasia and is connected to the Atlantic Ocean in the North Sea through the Denmark Straits. The dimensions of the water area are quite large for Europe - 419,000 sq.m, despite the fact that the average depth is 51 m (maximum 470 m). The Baltic Sea is full of water due to the large number of rivers that flow into it - the world-famous Vistula, Neman, Neva and Daugava. The largest among them (bringing large quantity water into the pool) is our Neva.

As for the shores of the Baltic Sea, relative to the mainland of the planet they stretch from southwest to northeast. The widest place on land is called the stretch of land from St. Petersburg to Stockholm - this is almost 650 km of continuous beach.

It is fair to note that the Baltic was not always under the sphere of Russian influence. These northern shores have long attracted kings and princes of appanage feudal states. Quite often, commanders together with armies tried to get a tasty morsel seashore, but I couldn’t get what I wanted. One has only to remember the bloody attempts of Tsar Ivan the Terrible and the failed Livonian War he started.

Fortune smiled on Russia only at the beginning of the 18th century. North War, which covered almost the entire northern and eastern parts of Europe, allowed Peter the Great to get his piece of the Gulf of Finland and begin the process of “Europeanization” of the Russian people.

Cities on the Baltic Sea in Russia

Today, the Baltic Sea is considered not only a strategic area, but also an excellent resort for residents of the country and neighboring regions. There's enough here cold water, sometimes capricious and violent, which, however, does not scare off the tourists who come here every summer.

Kaliningrad

(Port terminal Kaliningrad, located in the Kaliningrad Bay)

The central city of the region, as is known, was previously called Keninsberg. Today it is a large city on the sea, which has managed to preserve the outlines of German prosperity, while acquiring a typical Russian appearance. Today people come here not only to the grave of the great Kant, but also for medical mineral water and sandy beaches.

Svetlogorsk and Zelenogradsk

Two typical resort towns that differ only in size. The first one is larger and more touristy. A large number of hotels and restaurants for every taste; local residents have long adapted to the needs of guests and offer a quiet and cozy holiday on the seashore.

In addition, the region has a huge number of small villages in the coastal zone. Many of them mine amber and offer excursions to old breweries. Today, the Russian shores of the Baltic Sea have been completely Russified and the only reminders of the time when the lands belonged to Europe are the peaked roofs of churches and the two-story houses with red tiles stretching along the shore.

The Baltic Sea is located between Central and Northern Europe, part of the Atlantic Ocean basin. The reservoir washes the shores of such states as Russia, the Baltic countries (Estonia, Lithuania, Latvia), Poland, Germany, Denmark, and Scandinavian countries (Finland, Sweden). The water surface area is 415 thousand square meters. km. The volume is 21.7 thousand cubic meters. km. The maximum length is 1600 km. Maximum width is 193 km. The average depth is 55 meters, and the maximum is 459 meters. The length of the coastline is 8 thousand km.

Geography

The reservoir is connected by artificial canals with the North and White Seas. In the first case, this is the Kiel Canal (length 98 km). It allows ships to immediately enter the North Sea without rounding Jutland. In the eastern part of the canal is the German city of Kiel, in the western part is the city of Brunsbüttel. Concerning White Sea, then the path to it goes through the White Sea Canal.

The Baltic is naturally connected to the North Sea through the Kattegat (200 km long) and Skagerrak (240 km long) straits. It is a body of water between Jutland and Scandinavia.

Bays

The Baltic has the following large bays: Botanical, Finnish, Riga, Curonian.

Botanical Bay is located in the northern part of the body of water between Sweden and Finland. In the southern part it has the Åland Islands. Its area is 117 thousand square meters. km.

The Gulf of Finland is located in the eastern part of the Baltic. It washes the shores of Estonia, Russia and Finland. Its area is 29.5 thousand square meters. km. On its banks are located such large cities as St. Petersburg, Helsinki and Tallinn.

The Curonian Lagoon is a lagoon separated from the sea by the Curonian Spit. Its area is 1610 square meters. km. The waters of the bay belong to Lithuania and Kaliningrad region Russia. At the junction of this small reservoir with the sea is the city of Klaipeda.

Islands

The Åland Islands are an archipelago in Botanical Bay. There are 6,757 islands, but only 60 are inhabited by people. The most big islandÅland is considered to be with an area of ​​685 sq. km. The total area of ​​the archipelago is 1552 square meters. km.

The island of Gotland (Sweden) is located in the central part of the sea and 100 km from the Swedish coast. Its area is almost 3 thousand square meters. km. About 57 thousand people will live on it.

Another Swedish island is called Öland. Its area is 1342 sq. km. 25 thousand people live on this piece of land. Every summer they receive at least 500 thousand tourists.

The island of Bornholm, although located not far from the Swedish coast, belongs to Denmark. Its area is 588 square meters. km. 42 thousand people live on it. From the island to Copenhagen 169 km, and to Sweden 35 km.

Poland owns the island of Wolin with an area of ​​265 square meters. km. On it is the city of Wolin with a population of about 5 thousand people.

The island of Rügen belongs to Germany. Its area is 926 sq. km. It is home to 77 thousand people. These are the lands of the Prussian province of Pomerania.

The Estonian island of Saaremaa, part of the Moonsund archipelago, also belongs to the large islands. It belongs entirely to Estonia. As for Saaremaa, its area is 2.7 thousand square meters. km with a population of 35 thousand people. The archipelago has 4 large and approximately 500 small islands. Their total area is about 4 thousand square meters. km.

Rivers flowing into the Baltic Sea

Rivers such as the Neva with a length of 74 km, Narva (77 km), Daugava or Western Dvina (1020 km), Neman (937 km), Vistula (1047 km), Pregolya (123 km), Venta (124 km) flow into the salty reservoir ), Odra or Oder (903 km).

Baltic Sea on the map

Hydrology

The reservoir is notable for the fact that it constantly contains a large excess of fresh water. They come from rivers and as a result of precipitation. Surface salt waters flow into the North Sea through the Kattegat and Skagerrak straits. But salt water enters the Baltic in the same way, but only through the deep current. Tides are minor. Their size does not exceed 20 cm.

The wind has a much greater influence on the water level off the coast. It can raise the level up to 50 cm, and in narrow bays and bays up to 2 meters. If we talk about standing waves (seiches), then the amplitude of vibrations reaches 50 cm.

As for storms, the Baltic Sea is generally calm. The height of the waves does not exceed 4 meters. In rare cases, winds can create waves with a height of 10 meters. Since the salinity of the water is low, winter period Ship hulls may be subject to icing.

Ice appears in the bays in November. This applies to the northern and eastern regions. In this case, the thickness of the ice crust can reach 60-65 cm. The southern and central parts of the reservoir are not covered with ice. The ice cover disappears in April. In the north, floating ice floes can be found in June. Since 1720, the reservoir has frozen completely 20 times. The last such case was recorded in January 1987. During this period there was extremely harsh winter in Scandinavia.

In the central regions of the sea, the color of the water is bluish-green. It also has maximum transparency. The closer to the shores, the transparency decreases, and the color changes to pale green with a yellowish or brown tint. Poor transparency is often caused by plankton.

Water temperature and salinity

In the central parts of the sea, the temperature of the surface layers of water is 14-17 degrees Celsius. In Botanical Bay, the corresponding values ​​are 9-12 degrees Celsius. But in the Gulf of Finland it is 1 degree warmer than in the central part. At depth, the temperature first decreases and then increases. At the bottom it is 4-5 degrees Celsius.

The salinity of sea water decreases from west to east. At the extreme western points it is equal to 20 ppm at the sea surface. At depth it reaches 30 ppm. In the center of the reservoir, the salinity at the surface is 7-8 ppm. In the north it is 3 ppm, and in the east it is 2 ppm. With depth, these numbers increase and reach 13-14 ppm.

Helsinki Convention 1992

In 1992, the states whose shores are washed by the Baltic Sea signed a convention on the strict observance of environmental and maritime law in Baltic waters. Governing body Convention is the Helsinki Commission (HELCOM) or the Marine Environment Protection Commission. The contracting parties are Russia, Sweden, Finland, Estonia, Latvia, Lithuania, Denmark, Germany, Poland. Ratifications were deposited by Germany, Sweden and Latvia in 1994, Finland and Estonia in 1995, Denmark in 1996, Lithuania in 1997, Russia and Poland in 1999.

The Convention demonstrates the high responsibility that people have towards the unique region formed by the Baltic waters. Its flora and fauna should not be at risk of environmental disaster.

Window to Europe

The Baltic Sea is inland sea basin of the Atlantic Ocean and is located in a shallow depression between the Scandinavian Peninsula and the European continent. The Danish Straits system, through the North Sea, connects the Baltic Sea with the ocean.

Surface area - 386 thousand sq. km, average depth - 71 m, maximum - 459 m (Landsortsjupet basin south of Stockholm).

The ancient Slavs called this sea the Varangian Sea.

As a result of studying the bottom topography and the nature of the soil, scientists came to the conclusion that in the pre-glacial period there was land in place of the Baltic Sea. Then, during the Ice Age, the depression in which the sea is now located was filled with ice, the melting process of which led to the formation of a lake with fresh water.

About 14 thousand years ago, this lake connected with the ocean as a result of the subsidence of land areas - the lake turned into a sea. Then, after another rise of land in the region of Central Sweden, the connection between the sea and the ocean was broken, and it again turned into a closed lake-type reservoir.

About 7 thousand years ago, another subsidence of land occurred in the area of ​​​​the modern Danish Straits and the connection between the lake and the Atlantic was resumed.

Subsequent fluctuations in land level led to the formation of the modern Baltic Sea.

The rise of land in the area continues to this day. Thus, in the area of ​​the Gulf of Bothnia, the rise of the bottom is approximately 1 m per 100 years.

Climate in the maritime region it is temperate, characterized by slight seasonal temperature fluctuations, frequent precipitation in the form of rain, fog and snow.

Temperature surface water reaches +20 degrees C in summer. As you move north, the water is cooler and in the Gulf of Bothnia does not warm up above +9 - +10 degrees C. In winter, the water cools to freezing temperature and the northern bays of the sea become covered with ice. The central and southern regions usually remain ice-free, but during exceptionally cold winters the sea can become completely covered in ice.

Water in the sea it is highly desalinated, especially in areas remote from the Danish Straits. The reason is the numerous rivers and rivulets (almost 250) flowing into the sea.

Among the large rivers we can mention the Neva, Narva, Vistula, Kemijoki, Western Dvina, Neman, Odra.

Currents They form a cyclonic gyre in the sea, often their direction and speed are adjusted by the winds.

Tides in the sea they are very low - 5-10 cm, however, wind surges of water, especially in narrow bays, can exceed 3-4 meters.

Coastline The Baltic Sea is heavily indented. There are many large and small bays, bays, capes, and spits. The northern shores are rocky; as you move south, rocks and stones are replaced by sand and pebble mixtures and sand. Here the banks are low and flat.

The islands are of mainland origin, especially many small rocky islands in the northern part of the sea. Large islands: Gotland, Bornholm, Sarema.

Bottom relief the sea is complex. There are many rises and depressions here, which appeared as a result of the activity of glaciers, river beds, and land fluctuations. However, the elevation differences are small - the sea is shallow.

Animal world The Baltic Sea is relatively poor in species. A feature of the sea fauna is the distribution of freshwater and marine species of animals in different areas. The northern, fresher areas, especially near river mouths, are inhabited primarily by freshwater animals and species that can easily tolerate desalination. Closer to the Danish Straits, the sea waters are much saltier, so here you can find many typical sea ​​creatures. General species composition The sea is scarce, but quite rich in quantitative terms.

The poverty of the fauna of the sea is also explained by its youth, because in the form that it has now, its age is estimated at only five thousand years. Scientists predict that another 5,000 years will pass before the Baltic Sea will again lose its connection with the ocean and turn into a large fresh lake. Many shapes sea ​​life in such a short time they simply did not have time to adapt to local living conditions.

Nevertheless, the quantitative composition of animals living in the Baltic Sea is quite large.

Benthic species of animals are represented mainly by worms, gastropods and bivalves, small crustaceans and bottom fish- flounder, bulls. In some places you can find the mitten crab, a newcomer from the North Sea that has taken root here. Near the Danish Straits there is even a giant among jellyfish - cyanide. And another type of jellyfish - long-eared aurelia in the Baltic Sea it is found almost everywhere. Small schooling fish - three-spined stickleback, Baltic sprat.

In desalinated areas there is a lot of sea river fish: roach, perch, pike, bream, ide, pike perch, anadromous whitefish, burbot, etc.

In the Baltic Sea trade such valuable fish, like herring (about half of the total fish catch), sprat (sprat), salmon, eel, cod, flounder.

Marine mammals In the Baltic Sea there are only three species of seals: the gray seal (tyuvyak), the common seal (nerpa), and the common porpoise, which is a toothed cetacean.

Sharks in the Baltic Sea are represented only by the ubiquitous katran - a small spiny shark, which is dangerous to humans only with its spines on dorsal fins. But these fish are not settled in all areas of the sea - areas that are too desalinated and shallow are not suitable for them to live.

However, in the area of ​​the Danish Straits, connecting the Baltic with the North Sea, other predators are sometimes found - herring sharks. U Russian shores Baltic Sea such guests are not registered.

In conclusion, I would like to note that currently the Baltic Sea is intensively polluted by various chemical and biochemical wastewater, as well as microelements contained in precipitation. This leads to mass death of microflora and microfauna, in large quantities settling to the bottom and being processed by bacteria into hydrogen sulfide. And hydrogen sulfide has a detrimental effect on all living organisms in the bottom layer of water. If urgent measures are not taken, the number of aquatic animals in the sea will decrease significantly.

The salinity of which is about 20% of the salinity of the World Ocean, located in the northern part of Europe. It belongs to the type of inland seas. Its area is 419 square kilometers. It was the Baltic Sea during the reign of Peter the Great that became a window to Europe.

general characteristics

The average depth of the Baltic Sea is about 50 meters, the greatest recorded depth is 470 meters. The deepest water areas are located in the Scandinavian region, the shallowest areas are in the Curonian Spit area, where there is no depth of even 5 meters.

More than two hundred rivers flow into the Baltic Sea. The largest of them are Neman, Daugava, Vistula, Neva. Fresh river water is distributed unevenly in it, so the Baltic Sea has unequal salinity.

Ice cover in winter is established in the bays from November to April. The ice thickness reaches 60 cm. The southern regions of the sea can remain without ice cover all winter. Sometimes floating ice floes come across near the northern shores even in summer period. The last case of complete freezing of the Baltic Sea was recorded in 1987.

IN autumn-winter period The influx of North Sea salt waters increases due to a decrease in water temperature. Because of this, the salinity level in the sea increases.

Geographical features

The Baltic Sea is located in northwestern Europe. In the north it reaches almost the Arctic Circle, the coordinates of the extreme northern point of the sea are 65 degrees 40 minutes from the north. w. In the south it reaches 53 degrees 45 minutes. w. From east to west, the Baltic Sea extends from St. Petersburg (30 degrees 15 minutes east) to the city of Flensburg in Germany (30 degrees 10 minutes east).

The Baltic Sea is surrounded by coastline on almost all sides, only in the west does it have access to the North Sea. The White Sea Canal opens access to the White Sea. Largest part coast belongs to Sweden and Finland (35% and 17%), Russia has about 7%, the rest coastline divided between Germany, Denmark, Poland, Estonia, Lithuania and Latvia.

There are four large bays in the sea - Bothnian, Curonian, Finnish and Riga. The Curonian Lagoon is separated by the Curonian Spit and territorially belongs to Lithuania and Russia (Kaliningrad region). The Gulf of Bothnia is located between Sweden and Finland and contains the Åland archipelago. The Gulf of Finland is located in the east, adjacent to the shores of Finland, Estonia and Russia (St. Petersburg).

Baltic Sea: salinity and temperature regime

The temperature of the water surface in the central part is 15-17 degrees. In the Gulf of Bothnia, this figure does not rise above 12 degrees. The highest temperatures are recorded in the Gulf of Finland.

Due to weak water exchange and the constant supply of river water, this sea has low salinity. In addition, it does not have constant indicators. Thus, in the area of ​​​​the Danish coast, the salinity of the Baltic Sea water is 20 ppm at the surface. At depth the indicator can reach 30 ppm. The salinity of the surface waters of the Baltic Sea changes the amount east direction to a lesser extent. In the Gulf of Finland this figure is no more than 3 ppm.

Observations in last years recorded a trend of increasing salinity percentage. This figure increased by 0.5% compared to previous decades. Now the average salinity of the Baltic Sea is 8 ppm. The figure indicates that a liter of sea water contains 8 g of salt. This is the salinity of the Baltic Sea in grams.

Climate of the Baltic Sea

The Baltic has a temperate maritime climate. The average January temperature above the sea surface is 1-3 degrees, in the north and east - 4-8 degrees. Sometimes the invasion of cold currents from the Arctic lowers the temperature to -35 degrees for a short time. Prevails in winter North wind, which determines cold winter and a long, drawn-out spring.

IN summer time The wind direction changes to west and southwest. Rainy and cool summer weather sets in on the coast. Dry hot days in the Baltic are very rare. The average July temperature here is 14-19 degrees.

The average salinity of surface waters of the Baltic Sea depends on seasonality. The period of strong winds occurs in late autumn and winter. During a storm in November, waves rise up to 6 meters. In winter, ice prevents the formation of high waves. At this time, salinity decreases.

Animal world

The Baltic Sea, whose water salinity varies in different places, is inhabited by quite a variety of species - from purely marine to freshwater inhabitants. Thus, various mollusks, oysters, and crustaceans live in the salty waters of the Danish Straits. In some places there is even a visitor from the North Sea - the mitten crab.

Most commercial fish species choose central waters for their habitat, where the average salinity of the surface waters of the Baltic Sea is 7-9 ppm.

In bays with almost fresh water you can find pike, bream, crucian carp, roach, ide, burbot, and eel. IN industrial scale Baltic herring, cod, sprat, salmon and sea trout are fished here.

Resort holiday

Due to the cool climate, the resorts of the Amber Region are not to everyone’s taste. They have little in common with the hot beaches of Turkey, Egypt, and Crimea. Officially beach season lasts in the Baltic from June to the end of September, while in June the water does not always warm up to even 20 degrees.

However, not everyone likes hot, crowded beaches. Many people prefer to combine beach holiday with active, for example, with the study of culture and attractions. The beaches of the Baltic Sea are very a good option. You can choose the resort of Palanga, Jurmala, Gdansk, Sopot, Svetlogorsk and others. The ideal time for relaxation is July and the first half of August, when the water temperature warms up to 25 degrees. In the shallow waters of the Gulf of Riga, a temperature of 25-27 degrees was recorded.

Environmental problems of the Baltic Sea

In recent years, there has been a significant deterioration in water quality due to pollution. One of the reasons is that rivers flowing into the sea carry already polluted water. And since the sea is inland and has the only exit through the Danish Straits, there is no possibility of natural self-purification.

The following main water pollutants can be identified:

• industrial waste, Agriculture And utilities, which come from urban wastewater, often discharged directly into the sea;
• heavy metals - come from city runoff, some fall with precipitation;
• Spilled petroleum products - in the era of development of shipping, leakage of petroleum products is not uncommon.

The consequences of pollution are the formation of a film on the surface of the water and the cessation of oxygen access to its inhabitants.

Main sources of water pollution:

• active shipping;
• accidents at industrial enterprises and power plants;
• industrial and domestic wastewater;
• polluted rivers flowing into the sea.

Helsinki Convention

In 1992, nine Baltic states signed a convention on environmental and maritime rights. The main body is the commission, headquartered in Helsinki. The main goal of the commission is to develop and implement measures aimed at protecting the ecology of the marine environment, conducting research, and promoting the safe navigation of ships.

The commission is headed by states with access to the sea for a period of two years. From 2008 to 2010, Russia held the chairmanship.

Drunken forest and amber

In the Kaliningrad region on Curonian Spit There is an unusual place, popularly called the Dancing or Drunken Forest. Pine trees planted during the USSR grow in a small area (within 1 square km). The point is that the trees are strangely curved, and some are even twisted into a loop. Scientists cannot accurately explain this phenomenon. There are different versions: climate factor, genetics, pest attacks and even the influence of space. There are rumors that there are no sounds in the forest and mobile communications are lost. The mystery of the forest annually attracts domestic and foreign tourists.

In autumn, when a storm begins, the sea throws amber ashore along with sand. Mainly on the shores of Poland, Russia, and Germany. Local craftsmen and visiting adventurers await this period. There is a belief that amber is a stone for fulfilling desires. Amber souvenirs fill the atmosphere of the home with positive energy and promote harmony in personal relationships.

This is what the Baltic Sea is like, its salinity, climate and richness attract with its uniqueness.

Baltic Titanic

In 1994, on the night of September 28, a disaster occurred at sea, the mystery of which remains a mystery today. On the evening of September 27, the ferry Estonia departed from Tallinn on its last voyage. There were about 1,000 passengers and crew on board. The ship had been making a regular voyage to Stockholm for a long time. The route was familiar, no unforeseen situations were expected along the route. The sea was stormy, but neither passengers nor crew members were bothered by it. It was an ordinary Baltic autumn; it was believed that a storm would not be terrible for a vessel of this type.

Closer to midnight, the storm intensified, but the passengers were calm and getting ready for bed. By that time, the ferry had moved 350 km from the port. At this time, the ferry met the oncoming ship "Mariella". After one o'clock in the morning a distress signal was received from the ferry, after which the ship disappeared from radar. The Mariella and the ships nearby hurried to the scene of the tragedy. By three o'clock in the morning, rescue helicopters arrived at the crash site. Many victims no longer needed help - death occurred from hypothermia. In total, about 200 passengers were rescued, another 95 were identified and officially declared dead.