Information AboutBlack Sea |
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The Black Sea is an inland Sea between southeastern Europe and the Anatolian Peninsula ( Turkey ) and is ultimately connected to the Atlantic Ocean via the Mediterranean and Aegean Seas and various Strait s. The Bosporus strait connects it to the Sea Of Marmara , then the long island-bound strait of the Dardenelles to the Aegean Sea region of the Mediterranean. These waters separate eastern Europe and western Asia . The Black sea is also connected to the Sea Of Azov by the Strait Of Kerch . The Black Sea has an area of , 436,400 Km&2 —1 and a maximum depth of 2200 m. (7,218 ft.) 2 Like the Mediterranean Sea, there is a net inflow of seawater through the Bosporus into the oceanic region of some per year, that is lost to evaporation or into geologic faults and so gradually raises the salinity. Freshwater flows in from the surrounding areas, especially central and middle-eastern Europe, per year. The most important river entering the Black Sea is the 2006 . Countries bordering the Black Sea are n Peninsula is a Ukrainian autonomous republic. Important cities along the coast include: Constanţa (urban area of 401,613), Mangalia , Burgas , Varna (urban area of 357,752) , Odessa , Sevastopol , Yalta , Kerch , Novorossiysk (281,400), Sochi , Sukhumi , Poti , Batumi , Trabzon , Samsun (439,000) and Zonguldak . NAME Modern names of the Sea are universally equivalents of the English name, "Black Sea", including Bulgarian ''Cherno more'' (Черно море), Georgian ''Shavi zghva'' (შავი ზღვა), Laz ''Ucha Zuğa'', or simply ''Zuğa'' 'Sea', Romanian ''Marea Neagră'', Russian ''Chyornoye more'' (Чёрное море), Turkish ''Karadeniz'', Ukrainian ''Chorne more'' (Чорне море), Ubykh . This name cannot be traced to an earlier date than the Thirteenth Century , but there are indications that it may be considerably older. Strabo 's Geography (1.2.10) reports that in antiquity, the Black Sea was often just called "the Sea" (''pontos''). For the most part, Graeco-Roman tradition refers to the Black Sea as the 'Hospitable sea', ''Euxeinos Pontos'' (). This is a Euphemism replacing an earlier 'Inhospitable Sea', ''Pontos Axeinos'', first attested in Pindar (early fifth century BCE). Strabo (7.3.6) thinks that the Black Sea was called "inhospitable" before Greek colonization because it was difficult to navigate, and because its shores were inhabited by savage tribes; and that the name was changed to "hospitable" after the Milesians had colonized, making it part of Greek civilization. It is also possible that the name ''Axeinos'' arose by Popular Etymology from an Iranian ''axšaina-'' 'dark'; the designation "Black Sea" may thus date from Antiquity. The reason for the name may be an ancient assignment of colours to the direction of the compass — black referring to the north, and red referring to the south. Herodotus on one occasion uses Red Sea and Southern Sea interchangeably.Schmitt 1996 Another possible explanation comes from the colour of the Black Sea's deep waters. Being further north than the Mediterranean Sea and much less saline, the Microalgae concentration is much richer, causing the dark colour. Visibility in the Black Sea is on average approximately five meters (5.5 Yd ), as compared to up to thirty-five meters (38 yd) in the Mediterranean. One Bulgaria n understanding of the name is that the sea used to be quite stormy. Some sources stipulate that it goes back to the time of Noah's Ark . The Black Sea Deluge Theory is based on that idea. In Naval Science , the Black Sea is thought to have received its name because of its Hydrogen Sulfide layer that begins about 200 meters below the surface, and that ends all life from that point downward. GEOLOGY AND BATHYMETRY .]] The Black Sea forms an enclosed basin, located between south-eastern Europe and Asia Minor . The basin was formed during the Miocene Orogenies which uplifted the mountain ranges and divided the ancient Tethys Ocean into several brackish basins, including the Sarmatic Sea . The Caspian , Azov , Aral and Black Seas are the remnants of this evaporated basin. The basin is divided into two sub-basins by a convexity extending south from the just south of Yalta on the Crimean peninsula. The basin is connected to the Mediterranean Sea via the Turkish Straits System (TSS) in the south-west, which includes the Bosporus and Dardanelles straits and the Sea Of Marmara . The Black Sea is connected to the Sea Of Azov in the north-east via the Kerch straits. HYDROLOGY AND HYDROCHEMISTRY MODIS .]] The Black Sea is the world’s largest Meromictic basin where 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 current hydrochemical configuration is primarily controlled by basin topography and Fluvial inputs, which result in a strongly stratified vertical structure and a positive water balance. The upper layers are generally cooler, less dense and less salty than the deeper waters, as they are fed by large fluvial systems, whereas the deep waters originate from the warm, salty waters of the Mediterranean. This influx of dense water from Mediterranean is balanced by an outflow of fresher Black Sea surface-water into the Marmara Sea, maintaining the stratification and Salinity levels. The surface water has an average salinity of 18 to 18.5 Ppt and contains Oxygen and other nutrients required to sustain biotic activity. These waters circulate in a basin-wide anti-cyclonic shelfbreak Gyre known as the Rim Current which transports water round the perimeter of the Black Sea. Within this feature, two smaller cyclonic gyres operate, occupying the eastern and western sectors of the basin. Outside the Rim Current, numerous quasi-permanent coastal eddies are formed due to upwelling around the coastal apron and ‘wind curl’ mechanisms. The intra-annual strength of these features is controlled by seasonal atmospheric and fluvial variations. Sea Surface Temperature of the surface waters varies seasonally from 8° C to 30°C. Directly beneath the surface waters the Cold Intermediate Layer (CIL) is found. This layer is composed of cool, salty surface waters, which are the result of localised atmospheric cooling and decreased fluvial input during the winter months. The production of this water is focussed in the centre of the major gyres and on the NW shelf and as the water is not dense enough to penetrate the deep waters, Isopycnal Advection occurs, dispersing the water across the entire basin. The base of the CIL is marked by a major Thermocline , Halocline and Pycnocline at ~100-200m and this density disparity is the major cause of deep-water isolation. Below the pycnocline, salinity increases to 22 to 22.5 ppt and temperatures rise to around 8.5°C. The hydrochemical environment shifts from oxygenated to anoxic, as bacterial decomposition of sunken biomass utilises all of the free oxygen. Certain species of 2006 . Another danger to people posed by the anoxic layer could come from a small asteroid's impact into the Black Sea. Recently modelling shows there is a significant threat to life for people living on the sea's shore.R.D. Schuiling, R.B. Cathcart, V. Badescu, D. Isvoranu and E. Pelinovsky, "Asteroid impact in the Black Sea. Death by drowning or asphyxiation?", Natural Hazards (October 2006) DOI: 10.1007/s11069-006-0017-7 FAUNA |
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