estuary
Translation- estuary
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—estuarial /es'chooh air"ee euhl/, adj./es"chooh er'ee/, n., pl. estuaries.1. that part of the mouth or lower course of a river in which the river's current meets the sea's tide.2. an arm or inlet of the sea at the lower end of a river.[1530-40; < L aestuarium channel, creek, inlet, equiv. to aestu(s) tide + -arium -ARY]
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Partly enclosed coastal body of water in which river water is mixed with seawater.An estuary is thus defined by salinity rather than geography. Many coastal features designated by other names are in fact estuaries (e.g., Chesapeake Bay). Some of the oldest continuous civilizations have flourished in estuarine environments (e.g., the land between the Tigris and Euphrates rivers, the Nile delta, the Ganges delta, and the lower Huang He valley). Cities such as London (River Thames), New York (Hudson River), and Montreal (St. Lawrence River) developed on estuaries and became important commercial centres.* * *
▪ coastal featurepartly enclosed coastal body of water in which river water is mixed with seawater. In a general sense, the estuarine environment is defined by salinity boundaries rather than by geographic boundaries. Many coastal features that are designated by other names are in fact estuaries. For example, various coastal embayments, such as Chesapeake Bay and Galveston Bay, also are estuaries because fresh and salt water undergo considerable mixing. Moreover, most of the world's fjord systems are estuaries, as are large semienclosed tidal-flat regions and coastal marshes (e.g., the Waddenzee area of The Netherlands).A brief treatment of estuaries follows. For full treatment, see river: Estuaries (river).Estuaries have long been important as harbour (harbours and sea works) sites and centres of commerce. Some of the oldest continuous civilizations have flourished in such estuarine environments as the lower region of the Tigris and Euphrates (Tigris-Euphrates river system) rivers, the Po River delta region of Italy, the Nile (Nile River) delta, the Ganges (Ganges River) delta, and the lower Huang He valley. Developing civilizations soon discovered that the logical site for commercial seaports was the seawardmost point of the major river systems. Such cities as London ( Thames River), New York City ( Hudson River), Montreal (St. Lawrence River (Saint Lawrence River and Seaway)), Hamburg ( Elbe River), and Bordeaux ( Gironde estuary) have developed on estuaries and have become important centres of commerce.The geologic processes that form an estuary are extremely complex and varied, but it is clear that the existence of an estuary is largely dependent on the position of sea level relative to the freshwater discharge. If sea level were lowered, the estuarine zone would migrate seaward at the interface of the marine water and the edge of the newly exposed land area. Such migration has occurred in the past as a consequence of the Earth's several glaciations. For each glaciation, the primary source of moisture has been the oceans. Whenever sea level fell, the estuarine environment at the continental margin was forced to migrate in a seaward direction.About 18,000 years ago the Wisconsin Glacial Stage attained its maximum, and glacial melting began. The seas rose, forcing the estuarine environment to migrate back up the continental shelf. During the period of lowered sea level, some rivers had become entrenched in the continental shelf and deepened their valleys, which were soon flooded by the rising marine waters, forming a typical drowned river estuary. In areas such as Norway and parts of the coast of British Columbia, Can., valley glaciers had deepened river valleys. These narrow drowned glacial valleys became the modern fjord estuaries as sea level rose.The geomorphology (i.e., form) of an estuarine basin is usually developed by one of three agents: (1) fluvial or glacial erosion, (2) fluvial and marine deposition, or (3) tectonic activity. The last of these involves the down-faulting of a coastal area or the broad local subsidence of a stretch of coastline, as in the case of San Francisco Bay (northern Calif.).* * *
Universalium. 2010.
Look at other dictionaries:
Estuary — Es tu*a*ry, a. Belonging to, or formed in, an estuary; as, estuary strata. Lyell. [1913 Webster] … The Collaborative International Dictionary of English
estuary — noun эстуарий, дельта; устье реки … Англо-русский словарь Мюллера
Estuary — Es tu*a*ry, n.; pl. {Estuaries}. [L. aestuarium, from aestuare to surge. See {Estuate}.] [Written also {[ae]stuary}.] 1. A place where water boils up; a spring that wells forth. [Obs.] Boyle. [1913 Webster] 2. A passage, as the mouth of a river… … The Collaborative International Dictionary of English
estuary — 1> устье (реки); эстуарий, дельта 2> редк. морской рукав … Новый большой англо-русский словарь
Estuary — An estuary is a semi enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. [Pritchard, D. W. (1967) What is an estuary: physical viewpoint . p. 3 ndash;5 in: G. H. Lauf… … Wikipedia
estuary — ˈestjuərɪ сущ. эстуарий, дельта; устье реки устье (реки); эстуарий, дельта (редкое) морской рукав estuary эстуарий, дельта; устье реки … Большой англо-русский и русско-английский словарь
estuary — noun (plural aries) Etymology: Latin aestuarium, from aestus boiling, tide; akin to Latin aestas summer more at edify Date: 1538 a water passage where the tide meets a river current; especially an arm of the sea at the lower end of a river … New Collegiate Dictionary
estuary — The part of the wide lower course of a river where its current is met by the tides; an arm of the sea that extends inland to meet the mouth of a river … Fisheries — dictionary
estuary — (noun)) see estuarine … Dictionary of ichthyology
estuary — • лиман • устье … Англо-русский геологический словарь
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