Direction and extent of the Caspian Sea. Interesting facts about the Caspian Sea: depth, relief, coastline, resources. "Tortuga", fishing base

Holidays on the shores of the Caspian Sea– an excellent alternative for those who want to have a pleasant rest away from the hustle and bustle.

And also to gain new impressions and vitality, to improve the health of children, but does not have the financial means to travel to distant warm countries.

Cheap flights to Makhachkala

General information

The Caspian Sea, which is the largest lake in the world, stretches from North to South for approximately 1200 km. Its width is on average up to 320 km. The water surface area is about 370 thousand km2. The level of the Caspian Sea is almost 28 meters below ocean level.

The maximum depth was recorded in the South Caspian depression and is 1025 meters.

The unique sea-lake is rich in small islands, about 50 of them.

More than 100 rivers flow into the sea, among them the Volga, Ural, Kura, Atrek, Terek and others.

The Caspian Sea is famous for its unique flora and fauna.

In its warm waters you can find more than 850 species of fish and animals, and more than 500 species of plants. Many representatives of flora and fauna are listed in the Red Book.

The sea is rich in fish, including valuable sturgeon. The Caspian seal lives in warm waters. There are no sharks or other fish that are predatory and dangerous to humans.

Nature lovers can visit the famous Astrakhan International Biosphere Reserve. This is a magnificent natural monument.

In spring and summer, people especially come here to admire the amazingly beautiful phenomenon: fields of blooming lotus.

Russian resorts of the Caspian Sea

The length of the coast of the Russian part of the Caspian Sea is more than 600 kilometers.

Large sandy beaches, warm sea, pleasant weather - excellent prospects for organizing a quality summer holiday.

The best Russian resorts The Caspian Sea is located in Dagestan.

Makhachkala, Kaspiysk, Izberbash, Lagan, Derbent, Dagestan Lights - famous seaside resort towns.

Climate

The coast of the Astrakhan region has a temperate climate. Warm weather lasts from the first days of May until the first half of September.

During the season, clear, warm weather prevails ( average temperature 24-25 0 C). Cloudy days and rain are rare.

The hottest month is July.

In summer, the sea water warms up to 23-28°C along the entire length of the Russian coastline.

Accommodation

There are more than 150 boarding houses and recreation centers on the Caspian coast of Russia.

Vacationers can buy a ticket in advance or register on the spot.

In Derbent and Kaspiysk, tourists will be warmly greeted by the staff of large, comfortable hotels.

Small cozy hotels are also available for vacationers. family vacation. You can find comfortable housing in the private sector. Prices are very affordable .

How to get there?

You can get to the Astrakhan coast of the Caspian Sea by the following route: by train or plane to the regional center of Astrakhan, and then by bus, taxi or by water transport to your destination.

The resorts of Dagestan can be reached by local transport(bus, taxi) from the capital of the republic, Makhachkala, which can be reached by train or intercity bus.

Treatment

Those who wish can relax and undergo treatment at the Caspiy sanatorium, which is located on the seashore 40 km from Makhachkala.

This hydropathic clinic with healing mineral baths is equipped with modern diagnostic equipment.

The course of treatment is designed for 21 days, which gives a noticeable balneological effect.

Sanatorium "Lezzet"- climatic, sea, balneo-mud resort on the Caspian Sea. It is located 8 kilometers from Makhachkala airport.

Specialized areas: diseases of the nervous, musculoskeletal, genitourinary, digestive, cardiovascular, respiratory systems, gynecological problems and infertility.

The resort will help you combine seaside holidays with treatment "Talgi". The health resort is located in Makhachkala.

Specialization: treatment and prevention of diseases of the joints, nervous and genitourinary systems. Unique sulfide waters with hydrogen sulfide are used for treatment.

Recreation and entertainment

All resorts and health resorts on the Russian coast have developed infrastructure and created conditions for a good rest:

athletic facilities;
cafes, restaurants;
various attractions;
for those who wish to organize boat trips, fishing, thematic excursions.

Holidays in the Astrakhan region

The city of Astrakhan is located in the Caspian lowland in the delta of the Volga River. This old City included in tourist tours and is popular among travelers.

Guests are attracted by the wonderful architectural ensembles, majestic churches, interesting museums.

At the end of summer and autumn, you can enjoy the famous Astrakhan watermelons and fragrant melons from the garden.

From the regional center to the Caspian Sea is only 60 km.

The most common and affordable housing for vacationers and tourists in the Volga delta and on the Caspian coast are recreation centers. As a rule, these are small cozy houses located in picturesque corners.

"Dardanelles", recreation center

The Astrakhan region is an excellent region for lovers of fishing and active recreation.

Fishermen have long chosen the Dardanelles recreation center, located in the Volga River delta.

IN modern building The rooms are equipped with air conditioning, refrigerators, and bathrooms.

Dardanelles

For vacationers, high-quality meals are provided three times a day.

In the restaurant, the base can prepare delicious dishes from its own catch.

Vacationers have a sauna and billiards at their disposal. Guests are offered a variety of excursions, including to Astrakhan, boat trips on the sea and the Volga.

Address: s. Zaton, Kamyzyaksky district, Astrakhan region(base 9 km).

"Tortuga", fishing base

"Tortuga" in terms of cost of living is not very different from "Dardanelle".

A standard house has comfortable furniture, Appliances, necessary utensils, bathrooms. It is very comfortable for families with children to stay here.

Those who wish can stay in a floating house. Necessary for fishing Equipment can be rented on site.

Address: s. Vyshka, Limansky district, Astrakhan region.

Country of mountains - Dagestan- offers tourists the sandy beaches of the Caspian Sea, ski resorts, unique nature and culture, ancient monuments and wonderful national cuisine.

And although the idea of holidays in Dagestan is perceived ambiguously due to doubts about safety, many guests come to the republic. This mountain region is very beautiful and original.

Resort complex "Chindirchero"

This popular place holiday resort welcomes guests all year round.

In summer, guests can enjoy relaxing by the sea.

For vacationers:

windsurfing;
kiting;
rafting.

Chindirchero

All conditions for paragliding and rock climbing have also been created.

In winter, Chindirchero is a popular ski resort.

Address: s. Ginta, Akushinsky district, Makhachkala,

Derbent

Derbent, a city with a history of 5 thousand years, is one of the most attractive resorts for tourism on the shores of the Caspian Sea.

Derbent region is a subtropical paradise with a riot of nature and plenty of sun. The beauty of the sea coast is framed by picturesque mountains.

Derbent has many ancient monuments and interesting sights. Vacationers can enjoy exciting excursions, including helicopter ones. There are hotels, inns, and tourist centers both in the city and in its surroundings.

The most popular hotels in Derbent:

Hotel Krasny Bak;
Hotel Complex Europe;
Elit Hotel.

The resort can be reached by train or regular minibus from the bus station of Makhachkala or Kaspiysk. The Moscow - Baku train stops in Derbent.

Izberbash

This colorful city spread out at the foothills Greater Caucasus, covered with picturesque forests.

Izberbash

The warm sea, extensive sandy beaches, and amazing landscapes attract tourists.

The combination of sea and mountain air and the presence of healing mineral springs make it possible to improve your health.

Tourist base "Priboy"

The windows of the three-story building of the tourist center offer magnificent views. The living rooms have all the necessary amenities, air conditioning and televisions. Vacationers have a clean, well-maintained beach at their disposal.

The camp site offers delicious, healthy food, a cozy bar, and a guarded parking lot.

Address: pos. Primorsky, Izberbash.

Reviews

“We came for the first time from Orenburg. Nature is simply a miracle! Everything is so beautiful – I didn’t part with my camera. The base itself is a most picturesque corner. An ideal place to relax. It’s a pity that we didn’t provide complete information and came for a three-day tour.

Next time we'll try to stay longer. Excellent service. Such hospitality and cordiality is rare to find. We left with great regret. We will definitely come back."

“There are beaches in Derbent. But most of them are rented from private owners. City beaches usually quickly fill with garbage and are poorly cleaned, and this fact does not even soften the charm of clear, beautiful, warm sea water.”

Resorts of Kazakhstan on the Caspian Sea

Amazing nature and warm healing water the seas make holidays in the Caspian Sea very attractive.

People come to Kazakhstan to the coast to relax and improve their health. It offers comfortable sandy beaches, natural mineral springs and healing mud.

Aktau is the only city near the Caspian Sea in Kazakhstan.

On the Kazakh coast, the infrastructure is not yet very developed. However, there are already many pleasant places where tourists come with pleasure.

How to get there?

You can only get to Aktau by train or plane.

Getting there by road is difficult not only because of the very long distance, but also because of the quality of local roads.

Climate

On the coast of the Caspian Sea, winters are mild and summers are dry and warm.

On a summer day, the air temperature rises to +30..+32 degrees, and at night drops to +20 degrees.

The beach season lasts from May to September.

Accommodation

There will be no problems with accommodation in Aktau, even if you do not come with a tour package. There are more than 20 modern comfortable hotels in the city.

The most popular of them:

"Aktau";
"Chagala" ;
"Zheruyik."

Treatment

On the Kazakh coast of the Caspian Sea there are two large complex medical and recreational:

“Kenderli” – 300 km from Aktau;
Steagle, near the city.

The unique balneological hospital “Chagala” is located within the city.

Recreation and entertainment

"Kenderlik"

A sports and fitness complex is located near Aktau. It attracts lovers of active recreation.

This modern complex complies with all international norms and standards.

Kenderli

Guests stay in small cozy cottages located on the shore or in comfortable hotel rooms, which include a sauna, indoor pool, solarium and winter garden.

At the service of vacationers billiard, GYM's, tennis courts, outdoor summer swimming pool, football and volleyball courts, bowling alley, dance floor, bars and restaurant.

"Chagala", sanatorium

The sanatorium-preventorium “Chagala” (“Chaika”) offers quality recreation and recovery. This is a unique balneological hospital. It is located on the shores of the Caspian Sea, within the city of Aktau.

Guests are offered one and double rooms with amenities. The sanatorium building has a comfortable winter garden where you can relax and admire exotic plants.

Vacationers can visit Entertainment Center, casino, technology park, roller skating area.

New impressions will be given sightseeing tours By historical places And natural monuments Mangyshlak.

Address: Aktau, mn 1, coastal zone.

On the seashore, 18 kilometers from Aktau, there is a modern sports and recreational entertainment center “Stigl”.

There are two hotels on the territory of the center. This complex is equipped in accordance with international standards.

On its territory there is a unique sea sauna, SPA salon, fitness center, massage rooms, as well as cafes, restaurants, and attractions.

The territory of Russia is washed by twelve seas belonging to the basins of three oceans. But one of these seas - the Caspian - is often called a lake, which sometimes confuses people who have little understanding of geography.

Meanwhile, it is really more correct to call the Caspian a lake rather than a sea. Why? Let's figure it out.

A little geography. Where is the Caspian Sea located?

Occupying an area that exceeds 370,000 square kilometers, the Caspian Sea stretches from north to south, dividing the spaces of Europe and Asia with its water surface. Its coastline belongs to five different countries: Russia, Kazakhstan, Azerbaijan, Turkmenistan and Iran. Geographers conventionally divide its water area into three parts: the Northern (25% of the area), the Middle (36% of the area) and the Southern Caspian (39% of the area), which differ in climate, geological conditions and natural features. The coastline is predominantly flat, indented by river channels, covered with vegetation, and in the northern part, where the Volga flows into the Caspian Sea, it is also swampy.

The Caspian Sea has about 50 large and small islands, about one and a half dozen bays and six large peninsulas. In addition to the Volga, approximately 130 rivers flow into it, with nine rivers forming fairly wide and branched deltas. The annual drainage of the Volga is about 120 cubic kilometers. Together with other large rivers - Terek, Ural, Emba and Sulak - this accounts for up to 90% of the total annual flow into the Caspian Sea.

Why is the Caspian called a lake?

The main feature of any sea is the presence of straits connecting it to the ocean. The Caspian Sea is a closed or closed reservoir that receives river water, but is not connected to any ocean.

Its water contains a very small amount of salt compared to other seas (about 0.05%) and is considered slightly salty. Due to the absence of at least one strait connecting to the ocean, the Caspian Sea is often called the largest lake in the world, since the lake is a completely enclosed body of water that is fed only by river water.

The waters of the Caspian Sea are not subject to international maritime laws, and its waters are divided between all countries that are adjacent to it, in proportion to the coastline.

Why is the Caspian called a sea?

Despite all of the above, most often in geography, as well as in international and internal documents, the name “Caspian Sea” is used, and not “ Caspian lake" First of all, this is explained by the size of the reservoir, which is much more characteristic of the sea than of the lake. Even, which is much smaller in area than the Caspian Sea, local residents often called the sea. There are no other lakes in the world whose shores belong simultaneously to five different countries.

In addition, you should pay attention to the structure of the bottom, which near the Caspian Sea has a pronounced oceanic type. Once upon a time, the Caspian Sea most likely connected with the Mediterranean, but tectonic processes and drying out separated it from the World Ocean. There are more than fifty islands in the Caspian Sea, and the area of some of them is quite large, even by international standards they are considered large. All this allows us to call the Caspian a sea, and not a lake.

origin of name

Why is this sea (or lake) called the Caspian? The origin of any name is often associated with ancient history terrain. Different peoples who lived on the shores of the Caspian called it differently. More than seventy names of this reservoir have been preserved in history - it was called the Hyrcanian, Derbent, Sarai Sea, etc.

Iranians and Azerbaijanis still call it the Khazar Sea. It began to be called Caspian after the name of the ancient tribe of nomadic horse breeders who lived in the steppes adjacent to its coast - the numerous Caspian tribe. It was they who gave the name to the largest lake on our planet - the Caspian Sea.

CASPIAN SEA (Caspian), the largest on globe closed reservoir, endorheic brackish lake. Located on the southern border of Asia and Europe, it washes the shores of Russia, Kazakhstan, Turkmenistan, Iran and Azerbaijan. Due to the size, originality natural conditions and the complexity of hydrological processes, the Caspian Sea is usually classified as a closed inland sea.

The Caspian Sea is located in a vast area of internal drainage and occupies a deep tectonic depression. The water level in the sea is about 27 m below the level of the World Ocean, the area is about 390 thousand km 2, the volume is about 78 thousand km 3. The greatest depth is 1025 m. With a width of 200 to 400 km, the sea extends along the meridian for 1030 km.

The largest bays: in the east - Mangyshlaksky, Kara-Bogaz-Gol, Turkmenbashi (Krasnovodsky), Turkmensky; in the west - Kizlyarsky, Agrakhansky, Kizilagaj, Baku Bay; in the south there are shallow lagoons. There are many islands in the Caspian Sea, but almost all of them are small, with total area less than 2 thousand km 2. In the northern part there are numerous small islands adjacent to the Volga delta; larger ones - Kulaly, Morskoy, Tyuleniy, Chechen. Off the western shores is the Absheron archipelago, to the south lie the islands of the Baku archipelago, and off the eastern coast is the narrow island of Ogurchinsky, stretched from north to south.

The northern shores of the Caspian Sea are low-lying and very sloping, characterized by the widespread development of drying areas formed as a result of surge phenomena; deltaic shores are also developed here (deltas of the Volga, Ural, Terek) with an abundant supply of terrigenous material; the Volga delta with extensive reed thickets stands out. The western shores are abrasive, south of the Absheron Peninsula, mostly accumulative deltaic type with numerous bay bars and spits. Southern Shores low-lying. The eastern shores are mostly deserted and low-lying, composed of sand.

Relief and geological structure bottom.

The Caspian Sea is located in a zone of increased seismic activity. In the city of Krasnovodsk (now Turkmenbashi) in 1895, a powerful earthquake measuring 8.2 on the Richter scale occurred. On the islands and coast of the southern part of the sea, eruptions of mud volcanoes are often observed, leading to the formation of new shoals, banks and small islands, blurred by excitement and appearing again.

Based on the peculiarities of physical-geographical conditions and the nature of the bottom topography in the Caspian Sea, it is customary to distinguish the Northern, Middle and Southern Caspian Seas. The Northern Caspian Sea is distinguished by exceptionally shallow waters, located entirely within the shelf with average depths of 4-5 m. Even small changes in the level here on low-lying coasts lead to significant fluctuations in the area of the water surface, therefore the boundaries of the sea in the north-eastern part are shown with a dotted line on small-scale maps. The greatest depths (about 20 m) are observed only near the conventional border with the Middle Caspian, which is drawn along a line connecting the island of Chechen (north of the Agrakhan Peninsula) with Cape Tyub-Karagan on the Mangyshlak Peninsula. The Derbent depression (maximum depth 788 m) stands out in the bottom topography of the Middle Caspian Sea. The border between the Middle and Southern Caspian Sea passes over the Absheron threshold with depths of up to 180 m along a line from Chilov Island (east of the Absheron Peninsula) to Cape Kuuli (Turkmenistan). The Southern Caspian basin is the most extensive area of the sea with the greatest depths; almost 2/3 of the waters of the Caspian Sea are concentrated here, 1/3 is in the Middle Caspian, and less than 1% of the Caspian waters are located in the Northern Caspian due to shallow depths. In general, the topography of the Caspian Sea bottom is dominated by shelf areas (the entire northern part and a wide strip along the eastern coast of the sea). The continental slope is most pronounced on the western slope of the Derbent Basin and almost along the entire perimeter of the South Caspian Basin. On the shelf, terrigenous-shelly sands, shell, and oolitic sands are common; deep-sea areas of the bottom are covered with siltstone and silty sediments with a high content of calcium carbonate. In some areas of the bottom, bedrock of Neogene age is exposed. Mirabilite accumulates in the Kara-Bogaz-Gol Bay.

Tectonically, within the Northern Caspian Sea there are southern part The Caspian syneclise of the Eastern European Platform, which in the south is framed by the Astrakhan-Aktobe zone, composed of Devonian-Lower Permian carbonate rocks overlying a volcanic base and containing large deposits of oil and natural combustible gas. From the southwest, Paleozoic folded formations of the Donetsk-Caspian zone (or Karpinsky ridge) are thrust onto the syneclise, which is a protrusion of the foundation of the young Scythian (in the west) and Turanian (in the east) platforms, which are separated at the bottom of the Caspian Sea by the Agrakhan-Gurievsky fault (left shear) of northeastern strike. The Middle Caspian mainly belongs to the Turanian platform, and its southwestern margin (including the Derbent depression) is a continuation of the Terek-Caspian foredeep of the Greater Caucasus fold system. The sedimentary cover of the platform and trough, composed of Jurassic and younger sediments, contains deposits of oil and combustible gas in local uplifts. The Absheron threshold, separating the Middle Caspian from the South, is a connecting link of the Cenozoic folded systems of the Greater Caucasus and Kopetdag. The South Caspian basin of the Caspian Sea with crust of oceanic or transitional type is filled with a thick (over 25 km) complex of Cenozoic sediments. Numerous large hydrocarbon deposits are concentrated in the South Caspian Basin.

Until the end of the Miocene, the Caspian Sea was a marginal sea of the ancient Tethys Ocean (from the Oligocene - the relict oceanic basin of the Paratethys). By the beginning of the Pliocene, it lost contact with the Black Sea. The Northern and Middle Caspian Seas were drained, and the paleo-Volga valley stretched through them, the delta of which was located in the Absheron Peninsula region. Delta sediments have become the main reservoir of oil and natural combustible gas deposits in Azerbaijan and Turkmenistan. In the late Pliocene, in connection with the Akchagyl transgression, the area of the Caspian Sea greatly increased and the connection with the World Ocean was temporarily resumed. The waters of the sea covered not only the bottom of the modern depression of the Caspian Sea, but also the adjacent territories. In Quaternary time, transgressions (Apsheron, Baku, Khazar, Khvalyn) alternated with regressions. The southern half of the Caspian Sea is located in a zone of increased seismic activity.

Climate. The Caspian Sea, strongly elongated from north to south, is located within several climatic zones. In the northern part the climate is temperate continental, on the west coast it is warm temperate, southwestern and south coast lie within the subtropics; the east coast is dominated by a desert climate. IN winter time over the Northern and Middle Caspian, the weather is formed under the influence of Arctic continental and sea air, and the Southern Caspian is often under the influence of southern cyclones. The weather in the west is unstable and rainy, in the east it is dry. In summer, the western and northwestern regions are influenced by the spurs of the Azores atmospheric maximum, and the southeastern ones are influenced by the Iran-Afghan minimum, which together creates dry, stable warm weather. Over the sea, winds prevail in the northern and northwestern (up to 40%) and southeastern (about 35%) directions. Average wind speed is about 6 m/s, in central regions sea up to 7 m/s, in the area of the Absheron Peninsula - 8-9 m/s. Northern storm “Baku Nords” reach speeds of 20-25 m/s. The lowest average monthly air temperatures -10 °C are observed in January - February in the northeastern regions (in the most severe winters they reach -30 °C), in the southern regions 8-12 °C. In July - August, average monthly temperatures over the entire sea area are 25-26 °C, with a maximum of 44 °C on the east coast. The distribution of atmospheric precipitation is very uneven - from 100 mm per year on the eastern shores to 1700 mm in Lankaran. The open sea receives an average of about 200 mm of precipitation per year.

Hydrological regime. Changes in the water balance of an enclosed sea greatly influence changes in the volume of water and corresponding fluctuations in level. Average long-term components of the water balance of the Caspian Sea for the 1900-90s (km 3 /cm layer): river runoff 300/77, precipitation 77/20, underground runoff 4/1, evaporation 377/97, runoff to Kara-Bogaz- Gol 13/3, which forms a negative water balance of 9 km 3, or 3 cm of layer, per year. According to paleogeographic data, over the past 2000 years, the range of fluctuations in the level of the Caspian Sea has reached at least 7 m. Since the beginning of the 20th century, level fluctuations have shown a steady downward trend, as a result of which over 75 years the level dropped by 3.2 m and in 1977 reached -29 m (lowest position in the last 500 years). The sea surface area has decreased by more than 40 thousand km 2, which exceeds the area Sea of Azov. Since 1978, a rapid rise in level began, and by 1996 a mark of about -27 m relative to the level of the World Ocean was reached. In the modern era, fluctuations in the level of the Caspian Sea are determined mainly by fluctuations in climatic characteristics. Seasonal fluctuations in the level of the Caspian Sea are associated with the unevenness of river flow (primarily the Volga runoff), therefore the lowest level is observed in winter, the highest in summer. Short-term sharp changes in level are associated with surge phenomena and are most pronounced in shallow waters. northern regions and during storm surges can reach 3-4 m. Such surges cause flooding of large coastal areas of land. In the Middle and Southern Caspian Sea, surge fluctuations in level are on average 10-30 cm, under storm conditions - up to 1.5 m. The frequency of surges, depending on the region, is from one to 5 times a month, lasting up to one day. In the Caspian Sea, as in any closed body of water, seiche level fluctuations are observed in the form of standing waves with periods of 4-9 hours (wind) and 12 hours (tidal). The magnitude of seiche vibrations usually does not exceed 20-30 cm.

River flow in the Caspian Sea is distributed extremely unevenly. More than 130 rivers flow into the sea, which on average bring about 290 km 3 of fresh water per year. Up to 85% of the river flow falls on the Volga and the Urals and enters the shallow Northern Caspian Sea. Rivers west coast- Kura, Samur, Sulak, Terek, etc. - provide up to 10% of the flow. Another approximately 5% of fresh water is brought to the South Caspian by rivers on the Iranian coast. The eastern desert shores are completely deprived of constant fresh flow.

The average speed of wind currents is 15-20 cm/s, the highest - up to 70 cm/s. In the Northern Caspian, the prevailing winds create a flow directed along the northwestern coast to the southwest. In the Middle Caspian, this current merges with the western branch of the local cyclonic circulation and continues to move along the western coast. Near the Absheron Peninsula the current bifurcates. Its part in the open sea flows into the cyclonic circulation of the Middle Caspian, and the coastal part goes around the shores of the Southern Caspian and turns north, joining the coastal current that goes around the entire eastern coast. The average state of movement of Caspian surface waters is often disturbed due to variability in wind conditions and other factors. Thus, in the northeastern shallow area, a local anticyclonic gyre may arise. Two anticyclonic eddies are often observed in the Southern Caspian Sea. In the Middle Caspian in the warm season, stable northwest winds create southerly transport along the eastern coast. In light winds and during calm weather, currents may have other directions.

Wind waves develop very strongly, since the prevailing winds have a long acceleration length. Unrest develops mainly in the northwest and southeast directions. Strong storms are observed in the open waters of the Middle Caspian Sea, in the areas of Makhachkala, the Absheron Peninsula and the Mangyshlak Peninsula. The average wave height of greatest frequency is 1-1.5 m; at wind speeds of more than 15 m/s it increases to 2-3 m. Highest altitudes waves were recorded during strong storms in the area of the Neftyanye Kamni hydrometeorological station: annually 7-8 m, in some cases up to 10 m.

The water temperature on the sea surface in January - February in the Northern Caspian Sea is close to freezing temperature (about -0.2 - -0.3 °C) and gradually increases southward to 11 °C off the coast of Iran. In summer, surface waters warm up to 23-28 °C everywhere, except for the eastern shelf of the Middle Caspian Sea, where in July - August seasonal coastal upwelling develops and the surface water temperature drops to 12-17 °C. In winter, due to intense convective mixing, the water temperature changes little with depth. In summer, under the upper heated layer at horizons of 20-30 m, a seasonal thermocline (a layer of sharp temperature changes) is formed, separating deep cold waters from warm surface ones. In the bottom layers of water in deep-sea depressions, the temperature remains 4.5-5.5 °C all year round in the Middle Caspian and 5.8-6.5 °C in the Southern Caspian. Salinity in the Caspian Sea is almost 3 times lower than in open areas of the World Ocean, averaging 12.8-12.9‰. It should be especially emphasized that the salt composition of Caspian water is not completely identical to the composition ocean waters, which is explained by the isolation of the sea from the ocean. The waters of the Caspian Sea are poorer in sodium salts and chlorides, but richer in carbonates and sulfates of calcium and magnesium due to the unique composition of salts entering the sea with river and underground runoff. The highest salinity variability is observed in the Northern Caspian, where in the estuary areas of the Volga and Ural the water is fresh (less than 1‰), and as we move south, the salt content increases to 10-11‰ at the border with the Middle Caspian. The greatest horizontal salinity gradients are characteristic of the frontal zone between sea and river waters. The differences in salinity between the Middle and Southern Caspian Seas are small; salinity increases slightly from northwest to southeast, reaching 13.6‰ in the Turkmen Gulf (in Kara-Bogaz-Gol up to 300‰). Vertical changes in salinity are small and rarely exceed 0.3‰, which indicates good vertical mixing of waters. Water transparency varies widely from 0.2 m in estuarine areas large rivers up to 15-17 m in the central regions of the sea.

By ice regime The Caspian Sea is a partially frozen sea. Ice conditions are observed annually only in the northern regions. The Northern Caspian is completely covered by sea ice, the Middle Caspian is partially covered (only in severe winters). Middle border sea ice runs along an arc convex to the north, from the Agrakhan Peninsula in the west to the Tyub-Karagan Peninsula in the east. Ice formation usually begins in mid-November in the extreme northeast and gradually spreads to the southwest. In January, the entire Northern Caspian Sea is covered with ice, mostly fast ice (immobile). Drifting ice borders the fast ice with a strip 20-30 km wide. The average ice thickness is from 30 cm at the southern border to 60 cm in the northeastern regions of the Northern Caspian Sea, in hummocky accumulations - up to 1.5 m. The destruction of the ice cover begins in the 2nd half of February. In severe winters, drifting ice is carried south, along the western coast, sometimes to the Absheron Peninsula. At the beginning of April, the sea is completely free of ice cover.

History of the study. It is believed that the modern name of the Caspian Sea comes from the ancient Caspian tribes who inhabited the coastal areas in the 1st millennium BC; other historical names: Hyrkan (Irkan), Persian, Khazar, Khvalyn (Khvalis), Khorezm, Derbent. The first mention of the existence of the Caspian Sea dates back to the 5th century BC. Herodotus was one of the first to claim that this body of water is isolated, that is, it is a lake. In the works of Arab scientists of the Middle Ages there is information that in the 13th-16th centuries the Amu Darya partially flowed into this sea through one of its branches. The well-known numerous ancient Greek, Arabic, European, including Russian, maps of the Caspian Sea until the beginning of the 18th century did not reflect reality and were actually arbitrary drawings. By order of Tsar Peter I, in 1714-15, an expedition was organized under the leadership of A. Bekovich-Cherkassky, who explored the Caspian Sea, in particular its eastern shores. The first map, on which the contours of the coasts are close to modern ones, was compiled in 1720 using astronomical definitions by Russian military hydrographers F.I. Soimonov and K. Verdun. In 1731, Soimonov published the first atlas, and soon the first printed sailing guide of the Caspian Sea. A new edition of maps of the Caspian Sea with corrections and additions was carried out by Admiral A.I. Nagaev in 1760. The first information on the geology and biology of the Caspian Sea was published by S. G. Gmelin and P. S. Pallas. Hydrographic research in the 2nd half of the 18th century was continued by I.V. Tokmachev, M.I. Voinovich, and at the beginning of the 19th century by A.E. Kolodkin, who was the first to carry out instrumental compass surveying of the coast. Published in 1807 new map Caspian Sea, compiled taking into account the latest inventories. In 1837, systematic instrumental observations of sea level fluctuations began in Baku. The first was completed in 1847 Full description Gulf of Kara-Bogaz-Gol. In 1878, a General Map of the Caspian Sea was published, which reflected the results of the latest astronomical observations, hydrographic surveys and depth measurements. In 1866, 1904, 1912-13, 1914-15, under the leadership of N. M. Knipovich, expeditionary research was carried out on the hydrology and hydrobiology of the Caspian Sea; in 1934, the Commission for the Comprehensive Study of the Caspian Sea was created at the USSR Academy of Sciences. A great contribution to the study of the geological structure and oil content of the Absheron Peninsula and the geological history of the Caspian Sea was made by Soviet geologists I. M. Gubkin, D. V. and V. D. Golubyatnikovs, P. A. Pravoslavlev, V. P. Baturin, S. A . Kovalevsky; in the study of water balance and sea level fluctuations - B. A. Appolov, V. V. Valedinsky, K. P. Voskresensky, L.S. Berg. After the Great Patriotic War, systematic, comprehensive research was launched in the Caspian Sea, aimed at studying the hydrometeorological regime, biological conditions and geological structure of the sea.

In the 21st century in Russia, two large scientific centers are engaged in solving the problems of the Caspian Sea. Caspian Marine Research Center (CaspMNRC), created in 1995 by government decree Russian Federation, conducts research work in hydrometeorology, oceanography and ecology. The Caspian Research Institute of Fisheries (CaspNIRKH) traces its history back to the Astrakhan Research Station [established in 1897, since 1930 the Volga-Caspian Scientific Fisheries Station, since 1948 the Caspian Branch of the All-Russian Research Institute of Fisheries and Oceanography, since 1954 the Caspian Research Institute of Marine Fisheries and Oceanography (CaspNIRO), modern name since 1965]. CaspNIRH is developing the foundations for the conservation and rational use of biological resources of the Caspian Sea. It consists of 18 laboratories and scientific departments - in Astrakhan, Volgograd and Makhachkala. Has scientific fleet more than 20 ships.

Economic use. Natural resources The Caspian Sea is rich and varied. Significant hydrocarbon reserves are being actively developed by Russian, Kazakh, Azerbaijani and Turkmen oil and gas companies. There are huge reserves of mineral self-sedimented salts in the Kara-Bogaz-Gol Bay. The Caspian region is also known as a massive habitat for waterfowl and semi-aquatic birds. About 6 million migratory birds migrate across the Caspian Sea every year. In this regard, the Volga delta, Kyzylagaj, Northern Cheleken and Turkmenbashi bays are recognized as sites of international rank within the framework of the Ramsar Convention. The mouth areas of many rivers flowing into the sea have unique types of vegetation. The fauna of the Caspian Sea is represented by 1800 species of animals, of which 415 are vertebrate species. More than 100 species of fish live in the sea and river mouths. They have commercial significance marine species- herring, sprat, gobies, sturgeon; freshwater - carp, perch; Arctic “invaders” - salmon, white fish. Major ports: Astrakhan, Makhachkala in Russia; Aktau, Atyrau in Kazakhstan; Turkmenbashi in Turkmenistan; Bender-Torkemen, Bender-Anzeli in Iran; Baku in Azerbaijan.

Ecological state. The Caspian Sea is under powerful anthropogenic influence due to the intensive development of hydrocarbon deposits and the active development of fishing. In the 1980s, the Caspian Sea provided up to 80% of the world's sturgeon catch. Predatory fishing in recent decades, poaching and a sharp deterioration of the environmental situation have brought many valuable fish species to the brink of extinction. The living conditions of not only fish, but also birds and sea animals (Caspian seal) have deteriorated. Countries washed by the waters of the Caspian Sea are faced with the problem of creating a set of international measures to prevent pollution of the aquatic environment and developing the most effective environmental strategy for the near future. A stable ecological state is observed only in parts of the sea remote from the coast.

Lit.: Caspian Sea. M., 1969; Comprehensive studies of the Caspian Sea. M., 1970. Issue. 1; Gul K.K., Lappalainen T.N., Polushkin V.A. Caspian Sea. M., 1970; Zalogin B. S., Kosarev A. N. Seas. M., 1999; International tectonic map of the Caspian Sea and its frame / Ed. V. E. Khain, N. A. Bogdanov. M., 2003; Zonn I. S. Caspian Encyclopedia. M., 2004.

M. G. Deev; V. E. Khain (geological structure of the bottom).

On Sunday, August 12, in Aktau, Kazakhstan, the presidents of Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan signed the Convention on the Legal Status of the Caspian Sea. Previously, its status was regulated by Soviet-Iranian treaties, in which the Caspian Sea was defined as a closed (inland) sea, and each Caspian state had sovereign rights to a 10-mile zone and equal rights to the rest of the sea.

Now, according to the new convention, each country is assigned its own territorial waters (zones 15 miles wide). In addition, the provisions of the 1982 UN Convention on the Law of the Sea will not apply to the Caspian Sea, the seabed will be delimited into sectors, as is done by neighboring seas, and sovereignty over the water column will be established on the basis of the principle that it is a lake.

Why is the Caspian considered neither a lake nor a sea?

To be considered a sea, the Caspian Sea must have access to the ocean; this is one of the most important conditions for which a body of water can be called a sea. But the Caspian Sea has no access to the ocean, so it is considered a closed body of water not connected to the World Ocean.

The second feature that distinguishes sea waters from lake waters is their high salinity. The water in the Caspian Sea is indeed salty, but in its salt composition it occupies an intermediate position between the river and the ocean. In addition, in the Caspian Sea, salinity increases towards the south. The Volga delta contains 0.3‰ salts, and in the eastern regions of the Southern and Middle Caspian Sea the salinity reaches 13-14‰. And if we talk about the salinity of the World Ocean, it averages 34.7 ‰.

Due to its specific geographical and hydrological characteristics, the reservoir received a special legal status. The summit participants decided that the Caspian Sea is an inland body of water that does not have a direct connection with the World Ocean, and therefore cannot be considered a sea, and at the same time, due to its size, water composition and bottom features, cannot be considered a lake.

What has been achieved since the signing of the Convention?

The new treaty expands opportunities for cooperation between countries and also involves limiting any military presence of third countries. According to political scientist, director of the Institute newest states Alexey Martynov, the main achievement of the last summit is that its participants managed to stop any talk about the possible construction of military bases and NATO infrastructure facilities in the Caspian Sea.

“The most important thing that has been achieved is to record that the Caspian Sea will be demilitarized for everyone Caspian states. There will be no other military personnel there except those representing the countries that signed the Caspian Agreement. This is fundamental and main question, which was important to record. Everything else, what is divided proportionally into zones of influence, zones of extraction of biological resources, zones of extraction of shelf resources, was not so important. As we remember, in the last twenty years the military has been actively seeking to enter the region. The USA even wanted to build their own there military base", says Martynov.

In addition to the distribution of each country's shares in the oil and gas fields of the Caspian basin, the Convention also provides for the construction of pipelines. As stated in the document, the rules for laying them provide for the consent of only neighboring countries, and not all countries of the Caspian Sea. After signing the agreement, Turkmenistan, in particular, stated that it was ready to lay pipelines along the bottom of the Caspian Sea, which would allow it to export its gas through Azerbaijan to Europe. The consent of Russia, which previously insisted that the project could only be implemented with the permission of all five Caspian states, is now no longer required. They plan to subsequently connect the gas pipeline to the Trans-Anatolian gas pipeline, through which natural gas will flow through the territory of Azerbaijan, Georgia and Turkey to Greece.

“Turkmenistan is not a foreign country to us, but our partner, a country that we consider very important for us in the post-Soviet space. We cannot be against them receiving an additional impetus for development through such pipeline projects. Gas has long been coming from Turkmenistan and other countries through another pipeline system, somewhere it is even mixed with Russian gas, and there is nothing wrong with that. If this project works, everyone will benefit, including Russia. Under no circumstances should the project be considered as some kind of competition. The European market is so large and insatiable, I mean the energy market, that there is enough room for everyone,” says Martynov.

Today, almost all Turkmen gas is supplied to China, where Russia also intends to supply blue fuel. For this purpose, in particular, a large-scale project for the construction of the Power of Siberia gas pipeline is being implemented. Thus, the geography of gas supplies for both countries can expand - Turkmenistan will gain access to the European market, and Russia will be able to increase its gas supplies to China.

In dry and hot climates, a large amount of sea water evaporates, water molecules pass into the air. So, every year such a thing is carried away from the surface of the Caspian Sea great amount water particles that together they would fill a bowl with a volume of several hundred cubic kilometers. This amount of water could fill ten such reservoirs as Kuibyshevskoye.

But can water from the surface of the sea get into the bottom layers of the Caspian Sea, to a depth of 900-980 meters?

This is possible provided that the density of the surface layers of water is greater than the density of the bottom layers.

It is known that the density of sea water depends on salinity and temperature. The more salts the water contains, the denser it is, and therefore heavier. High temperature water is less dense than cold water. Only at low temperatures (about 0-4° Celsius) is the opposite relationship given, when water, heating up, becomes more dense.

High salinity of the surface layers of the sea is created in the hot season, when the water evaporates strongly, but the salt remains in the sea. At this time, the salinity of surface waters turns out to be no less, and even slightly greater than the salinity of deep and near-bottom layers.

The temperature of surface waters in the warm season is the same everywhere, about 25-28°, that is, five times higher than at a depth of 150-200 meters. With the onset of the cold season, the temperature of the surface layers decreases and during a certain period it turns out to be 5-6° above zero.

The temperature of the bottom and deep (deeper than 150-200 m) layers of the Caspian Sea is the same (5-6°), practically unchanged throughout the year.

Under these conditions, it is possible for denser surface cold and highly saline water to sink into the bottom layers.

Only in the southern regions of the Caspian Sea, the surface water temperature, as a rule, does not drop to 5-6° even in winter. And, although the sinking of surface water into the depths directly in these areas cannot occur, water that has sank from the surface in the more northern parts of the sea is brought here by deep currents.

A similar phenomenon is observed in the eastern part of the border zone between the Middle and Southern Caspian Seas, where cooled surface waters descend along southern slope boundary underwater threshold and then follow the deep current to the southern regions of the sea.

This widespread mixing of surface and deep waters is confirmed by the fact that oxygen was found at all depths of the Caspian Sea.

Oxygen can only reach depths with the surface layers of water, where it comes directly from the atmosphere or as a result of photosynthesis.

If there were no continuous supply of oxygen to the bottom layers, it would quickly be absorbed by animal organisms there or spent on the oxidation of soil organic matter. Instead of oxygen, the bottom layers would be saturated with hydrogen sulfide, which is what is observed in the Black Sea. The vertical circulation in it is so weak that oxygen in sufficient quantities does not reach the depth, where hydrogen sulfide is formed.

Although oxygen has been found at all depths of the Caspian Sea, it is not in the same quantity in different seasons of the year.

The water column is richest in oxygen in winter. The harsher the winter, that is, the lower the surface temperature, the more intense the aeration process occurs, which reaches the deepest parts of the sea. And vice versa, several warm winters in a row can cause the appearance of hydrogen sulfide in the bottom layers and even the complete disappearance of oxygen. But such phenomena are temporary and disappear during the first more or less severe winter.

The upper water column to a depth of 100-150 meters is especially rich in dissolved oxygen. Here the oxygen content ranges from 5 to 10 cubic meters. cm in liter. At depths of 150-450 m, there is much less oxygen - from 5 to 2 cubic meters. cm in liter.

Below 450 m there is very little oxygen and life is represented very sparsely - several species of worms and mollusks, small crustaceans.

Mixing of water masses is also caused by surge phenomena and waves.

Waves, currents, winter vertical circulation, surges, and surges operate constantly and are important factors in water mixing. It is not surprising, therefore, that no matter where we take a water sample in the Caspian Sea, its chemical composition will be constant everywhere. If there were no mixing of waters, all living organisms great depths died out. Life would only be possible in the photosynthetic zone.

Where the waters mix well and this process occurs quickly, for example in shallow areas of the seas and oceans, life is richer.

The constancy of the salt composition of the water of the Caspian Sea is a general property of the waters of the World Ocean. But this does not mean that the chemical composition of the Caspian Sea is the same as in the ocean or in any sea connected to the ocean. Consider a table showing the salt content in the waters of the ocean, the Caspian Sea and the Volga.

	Carbonates (CaCO 3)	Sulfates CaSO 4, MgSO 4	Chlorides NaCl, KCl, MgCl 2	Average water salinity ‰
Ocean	0,21	10,34	89,45
Caspian Sea	1,24	30,54	67,90	12,9
Volga river	57,2	33,4

The table shows that ocean water has very little in common with river water in terms of salt composition. In terms of salt composition, the Caspian Sea occupies an intermediate position between the river and the ocean, which is explained by the great influence of river runoff on the chemical composition of Caspian water. The ratio of salts dissolved in water Aral Sea, is closer to the salt composition of river water. This is understandable, since the ratio of the volume of river flow to the volume of water in the Aral Sea is much greater than for the Caspian Sea. A large amount of sulfuric acid salts in the Caspian Sea gives its water a bitter-salty taste, distinguishing it from the waters of the oceans and seas connected to them

The salinity of the Caspian Sea continuously increases towards the south. In the pre-estuary space of the Volga, a kilogram of water contains hundredths of a gram of salts. In the eastern regions of the Southern and Middle Caspian Sea, salinity reaches 13-14‰

The concentration of salts in Caspian water is low. So, in this water you can dissolve almost twenty times more salts than are present in it.

B.A. Shlyamin. Caspian Sea. 1954

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