Khelvachauri ( Georgian : ხელვაჩაურის მუნიციპალიტეტი , Khelvachauris Municiṕaliťeťi ) is a municipality in Georgia's southwestern autonomous republic of Adjara with a population of 52,737 people (2021). The administrative center is the town of Khelvachauri , which is located for the most part within the Batumi municipal boundaries since 2012. The municipality covers an area of 356.4 km (138 sq mi) and has 64 villages spread over 11 administrative units in the relatively densely populated hills around the city of Batumi.
64-510: Khelvachauri is the most southwestern municipality of Georgia and the area has been of great importance due to its strategic location with a rich historical past and a lot of cultural heritage. The modern municipality has 3 kilometers of coastline with the Black Sea in the extreme southwest and borders Turkey in the south. The border crossing at the village of Sarpi on the Black Sea coast
128-527: A halocline that stops at the Cold Intermediate Layer (CIL). This layer is composed of cool, salty surface waters, which are the result of localized atmospheric cooling and decreased fluvial input during the winter months. It is the remnant of the winter surface mixed layer. The base of the CIL is marked by a major pycnocline at about 100–200 metres (330–660 ft), and this density disparity
192-597: A coastline on the sea, its drainage basin includes parts of 24 countries in Europe. The Black Sea, not including the Sea of Azov , covers 436,400 km (168,500 sq mi), has a maximum depth of 2,212 m (7,257 ft), and a volume of 547,000 km (131,000 cu mi). Most of its coasts ascend rapidly. These rises are the Pontic Mountains to the south, bar the southwest-facing peninsulas,
256-484: A marked vertical stratification and a warm, shallow mixed layer. Day length and insolation intensity also control the extent of the photic zone . Subsurface productivity is limited by nutrient availability, as the anoxic bottom waters act as a sink for reduced nitrate , in the form of ammonia . The benthic zone also plays an important role in Black Sea nutrient cycling, as chemosynthetic organisms and anoxic geochemical pathways recycle nutrients which can be upwelled to
320-589: A strongly stratified vertical structure. Because of the extreme stratification, it is classified as a salt wedge estuary . Inflow from the Mediterranean Sea through the Bosporus and Dardanelles has a higher salinity and density than the outflow, creating the classic estuarine circulation. This means that the inflow of dense water from the Mediterranean occurs at the bottom of the basin while
384-433: A threat to health—and perhaps even life—for people living on the Black Sea coast. There have been isolated reports of flares on the Black Sea occurring during thunderstorms, possibly caused by lightning igniting combustible gas seeping up from the sea depths. The Black Sea supports an active and dynamic marine ecosystem, dominated by species suited to the brackish , nutrient-rich, conditions. As with all marine food webs,
448-529: A very thick convective bottom layer. The Black Sea undersea river is a current of particularly saline water flowing through the Bosporus Strait and along the seabed of the Black Sea. The discovery of the river, announced on August 1, 2010, was made by scientists at the University of Leeds and is the first of its kind to be identified. The undersea river stems from salty water spilling through
512-496: A weaker mixed assemblage of community development below the seasonal thermocline during summer months, and surface-intensified autumn production. This pattern of productivity is augmented by an Emiliania huxleyi bloom during the late spring and summer months. Since the 1960s, rapid industrial expansion along the Black Sea coastline and the construction of a major dam on the Danube have significantly increased annual variability in
576-762: Is 148 people per square kilometer. According to the 2014 census, the population of Khelvachauri consisted for 56.3% of Muslim Georgians , followed by Georgians belonging to the Georgian Orthodox Church (36.4%). Apart from a few dozen followers of the Armenian Apostolic Church , Catholics and a few Jews , no other religious minorities are represented. At 99.2%, the municipality consists almost exclusively of ethnic Georgians. There are small communities of roughly 100 Russians and Armenians and some 50 Abkhazians . Khelvachauri Municipal Assembly ( Georgian : ხელვაჩაურის საკრებულო)
640-631: Is a marginal mediterranean sea lying between Europe and Asia , east of the Balkans , south of the East European Plain , west of the Caucasus , and north of Anatolia . It is bounded by Bulgaria , Georgia , Romania , Russia , Turkey , and Ukraine . The Black Sea is supplied by major rivers, principally the Danube , Dnieper and Dniester . Consequently, while six countries have
704-401: Is a 3% increase compared to the last census of 2014. The municipality lost more than 33,000 residents to the city of Batumi in the period 2009-2011 due to border changes in the relatively densely populated area around Batumi. The administrative center Khelvachauri was absorbed for the most part, while Makhinjauri was completely absorbed into Batumi. The population density of the municipality
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#1732780627894768-594: Is a representative body in Khelvachauri Municipality, consisting of 24 members which are elected every four years. The last election was held in October 2021 . Zaza Diasamidze of Georgian Dream was elected mayor. The Batumi Bypass, part of the important S2 highway ( E70 ) between Poti and Turkey , is under construction in Khelvachauri Municipality to relieve the city of Batumi of through traffic. The S2 terminates in Khelvachauri Municipality at
832-412: Is administratively divided into 11 communities (თემი, temi) with 64 villages (სოფელი, sopeli). Since 2012, when Khelvachauri and Makhinjauri were (mostly) absorbed into Batumi city, there are no urban-type settlements (დაბა, daba) in the municipality. Villages in the municipality include Makho and Sarpi . The population of Khelvachauri Municipality is 52,737 according to the 2021 estimate, which
896-717: Is bisected by the Acharistsqali (literally "river of Adjara") and Machakhlistskali, both of which merge at Khelvachauri with the Chorokhi River from Turkey before reaching the Black Sea. In the north of the municipality lies the western extension of the Meskheti Range and in the borderland with Turkey the Shavsheti Range , both sub-ranges of the Lesser Caucasus . The highest mountains of
960-753: Is divided into two depositional basins—the Western Black Sea and Eastern Black Sea—separated by the Mid-Black Sea High, which includes the Andrusov Ridge, Tetyaev High, and Archangelsky High, extending south from the Crimean Peninsula . The basin includes two distinct relict back-arc basins which were initiated by the splitting of an Albian volcanic arc and the subduction of both the Paleo - and Neo- Tethys oceans, but
1024-719: Is generally accepted to be a rendering of the Iranian word * axšaina- ("dark colored"). Ancient Greek voyagers adopted the name as Á-xe(i)nos , identified with the Greek word áxeinos (inhospitable). The name Πόντος Ἄξεινος Póntos Áxeinos (Inhospitable Sea), first attested in Pindar ( c. 475 BC ), was considered an ill omen and was euphemized to its opposite, Εὔξεινος Πόντος Eúxeinos Póntos (Hospitable Sea), also first attested in Pindar. This became
1088-590: Is subject to interannual variability. Outside of the Rim Current, numerous quasi-permanent coastal eddies are formed as a result of upwelling around the coastal apron and "wind curl" mechanisms. The intra-annual strength of these features is controlled by seasonal atmospheric and fluvial variations. During the spring, the Batumi eddy forms in the southeastern corner of the sea. Beneath the surface waters—from about 50 to 100 metres (160 to 330 ft)—there exists
1152-460: Is the major mechanism for isolation of the deep water. Below the pycnocline is the Deep Water mass, where salinity increases to 22.3 PSU and temperatures rise to around 8.9 °C (48.0 °F). The hydrochemical environment shifts from oxygenated to anoxic, as bacterial decomposition of sunken biomass utilizes all of the free oxygen. Weak geothermal heating and long residence time create
1216-411: Is the most important of three Georgian-Turkish border crossings, with 1.36 million incoming foreign travellers in 2019. Furthermore, Khelvachauri borders the municipalities of Keda in the east, Kobuleti in the north, while most of the west side borders Batumi . The landscape of the municipality is typical of Adjara: green, humid subtropical hills and mountains. The southern side of the municipality
1280-587: The Bosporus ) Burgas , Varna , Constanța , Odesa , Sevastopol , Novorossiysk , Sochi , Poti , Batumi , Trabzon and Samsun . The Black Sea has a positive water balance , with an annual net outflow of 300 km (72 cu mi) per year through the Bosporus and the Dardanelles into the Aegean Sea . While the net flow of water through the Bosporus and Dardanelles (known collectively as
1344-749: The Caucasus Mountains to the east, and the Crimean Mountains to the mid-north. In the west, the coast is generally small floodplains below foothills such as the Strandzha ; Cape Emine , a dwindling of the east end of the Balkan Mountains ; and the Dobruja Plateau considerably farther north. The longest east–west extent is about 1,175 km (730 mi). Important cities along the coast include (clockwise from
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#17327806278941408-917: The Danube (northern Serbia, northern Bulgaria ( Danubian Plain ) and southern Romania ( Wallachian Plain ) to northeast Ukraine and further across the Central Black Earth Region and southern Russia into Siberia . The littoral zone of the Black Sea is often referred to as the Pontic littoral or Pontic zone . The largest bays of the Black Sea are Karkinit Bay in Ukraine; the Gulf of Burgas in Bulgaria; Dnieprovski Bay and Dniestrovski Bay, both in Ukraine; and Sinop Bay and Samsun Bay, both in Turkey. The largest rivers flowing into
1472-550: The Georgian-Turkish at the village of Sarpi on the Black Sea coast. This is the most important of three border crossings with Turkey, with 1.36 million incoming foreign travelers in 2019, and the 2nd most popular point of entry into Georgia after Tbilisi airport . Another important national route passes through Khelvachauri, the Sh1 Batumi - Akhaltsikhe which connects Adjara and Samtskhe-Javakheti across
1536-748: The North Atlantic oscillation , the climatic mechanisms resulting from the interaction between the north Atlantic and mid-latitude air masses. While the exact mechanisms causing the North Atlantic Oscillation remain unclear, it is thought the climate conditions established in western Europe mediate the heat and precipitation fluxes reaching Central Europe and Eurasia, regulating the formation of winter cyclones , which are largely responsible for regional precipitation inputs and influence Mediterranean sea surface temperatures (SSTs). The relative strength of these systems also limits
1600-632: The Santonian . Since its initiation, compressional tectonic environments led to subsidence in the basin, interspersed with extensional phases resulting in large-scale volcanism and numerous orogenies , causing the uplift of the Greater Caucasus , Pontides , southern Crimean Peninsula and Balkanides mountain ranges. During the Messinian salinity crisis in the neighboring Mediterranean Sea , water levels fell but without drying up
1664-516: The Turkish Straits ) is out of the Black Sea, water generally flows in both directions simultaneously: Denser, more saline water from the Aegean flows into the Black Sea underneath the less dense, fresher water that flows out of the Black Sea. This creates a significant and permanent layer of deep water that does not drain or mix and is therefore anoxic . This anoxic layer is responsible for
1728-643: The 13th century. A 1570 map Asiae Nova Descriptio from Abraham Ortelius 's Theatrum Orbis Terrarum labels the sea Mar Maggior (Great Sea), compare Latin Mare major . English writers of the 18th century often used Euxine Sea ( / ˈ j uː k s ɪ n / or / ˈ j uː k ˌ s aɪ n / ). During the Ottoman Empire , it was called either Bahr-e Siyah ( Perso-Arabic ) or Karadeniz ( Ottoman Turkish ), both meaning "Black Sea". The International Hydrographic Organization defines
1792-582: The Black Sea Depression they are terrigenous non-carbonate silts , and at the foot of the continental slope turbidite sediments. The Black Sea is the world's largest body of water with a meromictic basin. The deep waters do not mix with the upper layers of water that receive oxygen from the atmosphere. As a result, over 90% of the deeper Black Sea volume is anoxic water. The Black Sea's circulation patterns are primarily controlled by basin topography and fluvial inputs, which result in
1856-404: The Black Sea are: These rivers and their tributaries comprise a 2-million km (0.77-million sq mi) Black Sea drainage basin that covers wholly or partially 24 countries: Unrecognised states: Some islands in the Black Sea belong to Bulgaria, Romania, Turkey, and Ukraine: Short-term climatic variation in the Black Sea region is significantly influenced by the operation of
1920-585: The Black Sea features a range of trophic groups, with autotrophic algae, including diatoms and dinoflagellates , acting as primary producers. The fluvial systems draining Eurasia and central Europe introduce large volumes of sediment and dissolved nutrients into the Black Sea, but the distribution of these nutrients is controlled by the degree of physiochemical stratification, which is, in turn, dictated by seasonal physiographic development. During winter, strong wind promotes convective overturning and upwelling of nutrients, while high summer temperatures result in
1984-510: The Black Sea from the rest of the global ocean system. The large shelf to the north of the basin is up to 190 km (120 mi) wide and features a shallow apron with gradients between 1:40 and 1:1000. The southern edge around Turkey and the eastern edge around Georgia , however, are typified by a narrow shelf that rarely exceeds 20 km (12 mi) in width and a steep apron that is typically 1:40 gradient with numerous submarine canyons and channel extensions. The Euxine abyssal plain in
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2048-478: The Black Sea is called Siyābun . In the tenth-century Persian geography book Hudud al-'Alam , the Black Sea is called Georgian Sea ( daryā-yi Gurz ). The Georgian Chronicles use the name zğua sperisa ზღუა სპერისა (Sea of Speri) after the Kartvelian tribe of Speris or Saspers . Other modern names such as Chyornoye more and Karadeniz (both meaning Black Sea) originated during
2112-503: The Black Sea was an endorheic basin , operating independently of the global ocean system (similar to the Caspian Sea today). Currently, the Black Sea water level is relatively high; thus, water is being exchanged with the Mediterranean. The Black Sea undersea river is a current of particularly saline water flowing through the Bosporus Strait and along the seabed of the Black Sea, the first of its kind discovered. Current names of
2176-525: The Bosporus Strait from the Mediterranean Sea into the Black Sea, where the water has a lower salt content. Because of the anoxic water at depth, organic matter, including anthropogenic artifacts such as boat hulls, are well preserved. During periods of high surface productivity, short-lived algal blooms form organic rich layers known as sapropels . Scientists have reported an annual phytoplankton bloom that can be seen in many NASA images of
2240-483: The Bosporus is located at 36.5 m (120 ft) below present sea level (deepest spot of the shallowest cross-section in the Bosporus, located in front of Dolmabahçe Palace ) and has a wet section of around 38,000 m (410,000 sq ft). Inflow and outflow current speeds are averaged around 0.3 to 0.4 m/s (1.0 to 1.3 ft/s), but much higher speeds are found locally, inducing significant turbulence and vertical shear. This allows for turbulent mixing of
2304-629: The Goderdzi Pass. Since Makhinjauri is not part of Khelvachauri anymore, the municipality is left without train station. Batumi Central station north of the city is served by long-distance trains to Tbilisi. Batumi International Airport is the nearest airport, located south of Batumi on the north bank of the Chorokhi river. 41°35′08″N 41°40′08″E / 41.58556°N 41.66889°E / 41.58556; 41.66889 Black Sea Unrecognised states: The Black Sea
2368-659: The Municipality of Khelvachauri. During the Russo-Georgian War in 2008, several targets in the municipality were bombed by the Russian air force, including a military base that had been handed over by the Russian army a year earlier as part of the agreed departure from Georgia. Until the end of 2007, the Russian 12th Military Base was located in Batumi and Khelvachauri. Due to border changes in 2009 and 2011,
2432-576: The N:P:Si ratio in the basin. Coastal areas, accordingly, have seen an increase in the frequency of monospecific phytoplankton blooms, with diatom-bloom frequency increasing by a factor of 2.5 and non-diatom bloom frequency increasing by a factor of 6. The non-diatoms, such as the prymnesiophytes Emiliania huxleyi (coccolithophore), Chromulina sp., and the Euglenophyte Eutreptia lanowii , can out-compete diatom species because of
2496-464: The Rim Current. The Rim Current has a maximum velocity of about 50–100 cm/s (20–39 in/s). Within this feature, two smaller cyclonic gyres operate, occupying the eastern and western sectors of the basin. The Eastern and Western Gyres are well-organized systems in the winter but dissipate into a series of interconnected eddies in the summer and autumn. Mesoscale activity in the peripheral flow becomes more pronounced during these warmer seasons and
2560-471: The amount of cold air arriving from northern regions during winter. Other influencing factors include the regional topography , as depressions and storm systems arriving from the Mediterranean are funneled through the low land around the Bosporus, with the Pontic and Caucasus mountain ranges acting as waveguides, limiting the speed and paths of cyclones passing through the region. The Black Sea
2624-551: The cardinal directions , with black or dark for north, red for south, white for west, and green or light blue for east. Hence, "Black Sea" meant "Northern Sea". According to this scheme, the name could only have originated with a people living between the northern (black) and southern (red) seas : this points to the Achaemenids (550–330 BC). In the Greater Bundahishn , a Middle Persian Zoroastrian scripture,
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2688-532: The centre of the Black Sea reaches a maximum depth of 2,212 metres (7,257.22 feet) just south of Yalta on the Crimean Peninsula . The Paleo- Euxinian is described by the accumulation of eolian silt deposits (related to the Riss glaciation ) and the lowering of sea levels ( MIS 6, 8 and 10). The Karangat marine transgression occurred during the Eemian Interglacial (MIS 5e). This may have been
2752-533: The city of Batumi. Despite the relatively small difference in height near Batumi, the hilly area crammed with villages means that this bypass will consist almost entirely of bridges and tunnels. In the second half of the 19th century, Abkhazian Muhajirs arrived in villages in the current municipality of Khelvachauri, then under Ottoman rule, when the Russian Empire brutally placed the associated principality of Abkhazia under military rule and deported
2816-518: The commonly used designation in Greek, although in mythological contexts the "true" name Póntos Áxeinos remained favoured. Strabo 's Geographica (1.2.10) reports that in antiquity, the Black Sea was often simply called "the Sea" ( ὁ πόντος ho Pontos ). He thought that the sea was called the "Inhospitable Sea Πόντος Ἄξεινος Póntos Áxeinos by the inhabitants of the Pontus region of
2880-512: The highest sea levels reached in the late Pleistocene . Based on this some scholars have suggested that the Crimean Peninsula was isolated from the mainland by a shallow strait during the Eemian Interglacial. The Neoeuxinian transgression began with an inflow of waters from the Caspian Sea . Neoeuxinian deposits are found in the Black Sea below −20 m (−66 ft) water depth in three layers. The upper layers correspond with
2944-759: The insurgent population to the Ottoman Empire. Descendants of these still live in the villages of Silabauri, Peria and Mnatobi in the periphery of Batumi. After the Russian takeover of Adjara in 1878, the territory of the present-day Municipality of Khelvachauri was incorporated into the Batum Oblast until 1917. With the Sovietization of Georgia from 1921, the area was administratively separated in 1924 and it fell successively under Chorokhi Uyezd , Batumi Uyezd (1929), Batumi Raion (1930-1968), Khelvachauri District (1968-2006) and finally from 2006
3008-518: The late 1980s. Additionally, an alien species—the warty comb jelly ( Mnemiopsis leidyi )—established itself in the basin, exploding from a few individuals to an estimated biomass of one billion metric tons. The change in species composition in Black Sea waters also has consequences for hydrochemistry, as calcium-producing coccolithophores influence salinity and pH, although these ramifications have yet to be fully quantified. In central Black Sea waters, silicon levels also reduced significantly, due to
3072-407: The limited availability of silicon, a necessary constituent of diatom frustules. As a consequence of these blooms, benthic macrophyte populations were deprived of light, while anoxia caused mass mortality in marine animals. Overfishing during the 1970s further compounded the decline in macrophytes, while the invasive ctenophore Mnemiopsis reduced the biomass of copepods and other zooplankton in
3136-702: The limits of the Black Sea as follows: On the Southwest. The Northeastern limit of the Sea of Marmara [A line joining Cape Rumili with Cape Anatoli (41°13'N)]. In the Kertch Strait . A line joining Cape Takil and Cape Panaghia (45°02'N). The area surrounding the Black Sea is commonly referred to as the Black Sea Region . Its northern part lies within the Chernozem belt (black soil belt) which goes from eastern Croatia ( Slavonia ), along
3200-658: The municipality are in the Shavsheti Range, reaching over 2,000 metres (6,600 ft) above sea level, while the Meskheti Range in the northeastern corner of the municipality reaches heights around 1,300 metres (4,300 ft) meters above sea level. This is where the Mtirala National Park is located, whose name is derived from the large amount of rain that falls in the area. It is the wettest area in Georgia. Due to its location directly around Batumi and
3264-539: The municipality lost a total of more than 50 km² of territory to Batumi, both to the north, east and south of the city, including an important part of the coastline. This area also included the dabas Makhinjauri and Khelvachauri (the administrative center of the municipality), a dozen villages, but also the famous Batumi Botanical Garden at the Green Cape (Mtsvane Kontskhi) and the historic Fort Gonio and Black Sea beaches at Kvariati . Khelvachauri Municipality
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#17327806278943328-465: The natural beauty present in all directions, the municipality also benefits from tourism to the city, and the area is relatively popular among day trippers. Closer to Batumi, the hills are only a few hundred meters high, where many villages are located. Through this hilly area the Batumi Bypass is under construction, part of the important S2 highway ( E70 ) between Poti and Turkey, to relieve
3392-752: The others being the Red Sea , the White Sea and the Yellow Sea . The earliest known name of the Black Sea is the Sea of Zalpa, so called by both the Hattians and their conquerors, the Hittites . The Hattic city of Zalpa was "situated probably at or near the estuary of the Marrassantiya River, the modern Kızıl Irmak , on the Black Sea coast." The principal Greek name Póntos Áxeinos
3456-454: The outflow of fresher Black Sea surface-water into the Sea of Marmara occurs near the surface. According to Gregg (2002), the outflow is 16,000 cubic metres per second (570,000 cubic feet per second) or around 500 cubic kilometres per year (120 cubic miles per year), and the inflow is 11,000 m /s (390,000 cu ft/s) or around 350 km /a (84 cu mi/a). The following water budget can be estimated: The southern sill of
3520-448: The peak of the Khvalinian transgression, on the shelf shallow-water sands and coquina mixed with silty sands and brackish-water fauna, and inside the Black Sea Depression hydrotroilite silts. The middle layers on the shelf are sands with brackish-water mollusc shells. Of continental origin, the lower level on the shelf is mostly alluvial sands with pebbles, mixed with less common lacustrine silts and freshwater mollusc shells . Inside
3584-488: The photic zone, enhancing productivity. In total, the Black Sea's biodiversity contains around one-third of the Mediterranean's and is experiencing natural and artificial invasions or "Mediterranizations". The main phytoplankton groups present in the Black Sea are dinoflagellates , diatoms , coccolithophores and cyanobacteria . Generally, the annual cycle of phytoplankton development comprises significant diatom and dinoflagellate-dominated spring production, followed by
3648-497: The preservation of ancient shipwrecks which have been found in the Black Sea, which ultimately drains into the Mediterranean Sea , via the Turkish Straits and the Aegean Sea. The Bosporus strait connects it to the small Sea of Marmara which in turn is connected to the Aegean Sea via the strait of the Dardanelles . To the north, the Black Sea is connected to the Sea of Azov by the Kerch Strait . The water level has varied significantly over geological time. Due to these variations in
3712-437: The region. As a result of these characteristics the Black Sea has gained interest from the field of marine archaeology , as ancient shipwrecks in excellent states of preservation have been discovered, such as the Byzantine wreck Sinop D , located in the anoxic layer off the coast of Sinop, Turkey . Modelling shows that, in the event of an asteroid impact on the Black Sea, the release of hydrogen sulfide clouds would pose
3776-414: The sea are usually equivalents of the English name "Black Sea", including these given in the countries bordering the sea: Such names have not yet been shown conclusively to predate the 13th century. In Greece , the historical name "Euxine Sea", which holds a different literal meaning (see below), is still widely used: The Black Sea is one of four seas named in English after common color terms –
3840-415: The sea. The collision between the Eurasian and African plates and the westward escape of the Anatolian block along the North Anatolian and East Anatolian faults dictates the current tectonic regime, which features enhanced subsidence in the Black Sea basin and significant volcanic activity in the Anatolian region. These geological mechanisms, in the long term, have caused the periodic isolations of
3904-441: The southern shoreline before Greek colonisation due to its difficult navigation and hostile barbarian natives (7.3.6), and that the name was changed to "hospitable" after the Milesians colonised the region, bringing it into the Greek world. Popular supposition derives "Black Sea" from the dark color of the water or climatic conditions. Some scholars understand the name to be derived from a system of colour symbolism representing
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#17327806278943968-439: The timings of these events remain uncertain. Arc volcanism and extension occurred as the Neo-Tethys Ocean subducted under the southern margin of Laurasia during the Mesozoic . Uplift and compressional deformation took place as the Neotethys continued to close. Seismic surveys indicate that rifting began in the Western Black Sea in the Barremian and Aptian followed by the formation of oceanic crust 20 million years later in
4032-408: The two layers. Surface water leaves the Black Sea with a salinity of 17 practical salinity units (PSU) and reaches the Mediterranean with a salinity of 34 PSU. Likewise, an inflow of the Mediterranean with salinity 38.5 PSU experiences a decrease to about 34 PSU. Mean surface circulation is cyclonic ; waters around the perimeter of the Black Sea circulate in a basin-wide shelfbreak gyre known as
4096-399: The water level in the basin, the surrounding shelf and associated aprons have sometimes been dry land. At certain critical water levels, connections with surrounding water bodies can become established. It is through the most active of these connective routes, the Turkish Straits, that the Black Sea joins the World Ocean . During geological periods when this hydrological link was not present,
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