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Yoldia Sea
Yoldia Sea is a name given by geologists to a variable brackish water stage in the Baltic Sea basin that prevailed after the Baltic Ice Lake was drained to sea level during the Weichselian glaciation. Dates for the Yoldia sea are obtained mainly by radiocarbon dating material from ancient sediments and shore lines and from clay-varve chronology. They tend to vary by as much as a thousand years, but a good estimate is 10,300 – 9500 radiocarbon years BC, equivalent to ca 11,700–10,700 calendar years BC. The sea ended gradually when isostatic rise of Scandinavia closed or nearly closed its effluents, altering the balance between saline and fresh water. The Yoldia Sea became Ancylus Lake. The Yoldia Sea stage had three phases of which only the middle phase had brackish water. The name of the sea is adapted from the obsolete name of the bivalve, ''Portlandia arctica'' (previously known as ''Yoldia arctica''), found around Stockholm. This bivalve requires cold saline water. It cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackish Water
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root '' brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (‰), which is a specific gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strait Of Närke
A strait is an oceanic landform connecting two seas or two other large areas of water. The surface water generally flows at the same elevation on both sides and through the strait in either direction. Most commonly, it is a narrow ocean channel that lies between two land masses. Some straits are not navigable, for example because they are either too narrow or too shallow, or because of an unnavigable reef or archipelago. Straits are also known to be loci for sediment accumulation. Usually, sand-size deposits occur on both the two opposite strait exits, forming subaqueous fans or deltas. Terminology The terms ''channel'', ''pass'', or ''passage'' can be synonymous and used interchangeably with ''strait'', although each is sometimes differentiated with varying senses. In Scotland, ''firth'' or ''Kyle'' are also sometimes used as synonyms for strait. Many straits are economically important. Straits can be important shipping routes and wars have been fought for control of them. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger oceans, they do form part of the Earth's water cycle. Lakes are distinct from lagoons, which are generally coastal parts of the ocean. Lakes are typically larger and deeper than ponds, which also lie on land, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which usually flow in a channel on land. Most lakes are fed and drained by rivers and streams. Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers, where a river channel has widened into a basin. Some parts of the world have many lakes formed by the chaotic drainage patterns left over from the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesolithic
The Mesolithic (Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymously, especially for outside northern Europe, and for the corresponding period in the Levant and Caucasus. The Mesolithic has different time spans in different parts of Eurasia. It refers to the final period of hunter-gatherer cultures in Europe and Western Asia, between the end of the Last Glacial Maximum and the Neolithic Revolution. In Europe it spans roughly 15,000 to 5,000 BP; in Southwest Asia (the Epipalaeolithic Near East) roughly 20,000 to 10,000 BP. The term is less used of areas farther east, and not at all beyond Eurasia and North Africa. The type of culture associated with the Mesolithic varies between areas, but it is associated with a decline in the group hunting of large animals in favour of a broader hunter-g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boreal (period)
In paleoclimatology of the Holocene, the Boreal was the first of the Blytt–Sernander sequence of north European climatic phases that were originally based on the study of Danish peat bogs, named for Axel Blytt and Rutger Sernander, who first established the sequence. In peat bog sediments, the Boreal is also recognized by its characteristic pollen zone. It was preceded by the Younger Dryas, the last cold snap of the Pleistocene, and followed by the Atlantic, a warmer and moister period than our most recent climate. The Boreal, transitional between the two periods, varied a great deal, at times having within it climates like today's. Subdividing the Boreal Subsequent to the original Blytt-Sernander scheme, the first stage of the Boreal was divided off as a Pre-boreal transitional phase, followed by the Boreal proper. Some current schemes based on pollen zones also distinguish a pre-Boreal (pollen zone IV), an early Boreal (pollen zone V) and a late Boreal (pollen zone VIa, b, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Ladoga
Lake Ladoga (; rus, Ла́дожское о́зеро, r=Ladozhskoye ozero, p=ˈladəʂskəjə ˈozʲɪrə or rus, Ла́дога, r=Ladoga, p=ˈladəɡə, fi, Laatokka arlier in Finnish ''Nevajärvi'' ; vep, Ladog, Ladoganjärv) is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg. It is the largest lake located entirely in Europe, the second largest lake after Baikal in Russia, and the 14th largest freshwater lake by area in the world. ''Ladoga Lacus'', a methane lake on Saturn's moon Titan, is named after the lake. Etymology In one of Nestor's chronicles from the 12th century a lake called "the Great Nevo" is mentioned, a clear link to the Neva River and possibly further to Finnish ''nevo'' 'sea' or ''neva'' 'bog, quagmire'. Evgeny Pospelov: ''Geographical names of the world. Toponymic dictionary.'' Second edition. Astrel, Moscow 2001, pp. 106f. Ancient Norse sagas and Hanseatic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neva River
The Neva (russian: Нева́, ) is a river in northwestern Russia flowing from Lake Ladoga through the western part of Leningrad Oblast (historical region of Ingria) to the Neva Bay of the Gulf of Finland. Despite its modest length of , it is the fourth-largest river in Europe in terms of average discharge (after the Volga, the Danube and the Rhine). The Neva is the only river flowing from Lake Ladoga. It flows through the city of Saint Petersburg, the three smaller towns of Shlisselburg, Kirovsk and Otradnoye, and dozens of settlements. It is navigable throughout and is part of the Volga–Baltic Waterway and White Sea–Baltic Canal. It is the site of many major historical events, including the Battle of the Neva in 1240 which gave Alexander Nevsky his name, the founding of Saint Petersburg in 1703, and the Siege of Leningrad by the German army during World War II. The river played a vital role in trade between Byzantium and Scandinavia. Etymology The earliest people i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archipelago
An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands. Examples of archipelagos include: the Indonesian Archipelago, the Andaman and Nicobar Islands, the Lakshadweep Islands, the Galápagos Islands, the Japanese archipelago, the Philippine Archipelago, the Maldives, the Balearic Islands, The Bahamas, the Aegean Islands, the Hawaiian Islands, the Canary Islands, Malta, the Azores, the Canadian Arctic Archipelago, the British Isles, the islands of the Archipelago Sea, and Shetland. They are sometimes defined by political boundaries. For example, the Gulf archipelago off the northeastern Pacific coast forms part of a larger archipelago that geographically includes Washington state's San Juan Islands; while the Gulf archipelago and San Juan Islands are geographically related, they are not technically included in the same archipelago due to manmad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Finland
The Gulf of Finland ( fi, Suomenlahti; et, Soome laht; rus, Фи́нский зали́в, r=Finskiy zaliv, p=ˈfʲinskʲɪj zɐˈlʲif; sv, Finska viken) is the easternmost arm of the Baltic Sea. It extends between Finland to the north and Estonia to the south, to Saint Petersburg in Russia to the east, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn. The eastern parts of the Gulf of Finland belong to Russia, and some of Russia's most important oil harbors are located farthest in, near Saint Petersburg (including Primorsk). As the seaway to Saint Petersburg, the Gulf of Finland has been and continues to be of considerable strategic importance to Russia. Some of the environmental problems affecting the Baltic Sea are at their most pronounced in the shallow gulf. Proposals for a tunnel through the gulf have been made. Geography The gulf has an area of . The length (from the Hanko Peninsula to Saint Petersburg) is and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Bothnia
The Gulf of Bothnia (; fi, Pohjanlahti; sv, Bottniska viken) is divided into the Bothnian Bay and Bothnian Sea, and it is the northernmost arm of the Baltic Sea, between Finland's west coast ( East Bothnia) and the Sweden's east coast (West Bothnia and North Bothnia). In the south of the gulf lies Åland, between the Sea of Åland and the Archipelago Sea. Name Bothnia is a latinization. The Swedish name was originally just , with being Old Norse for "gulf" or "bay", which is also the meaning of the second element . The name was applied to the Gulf of Bothnia as in Old Norse, after , which at the time referred to the coastland west of the gulf. Later, was applied to the regions on the western side and the eastern side ('East Bottom' and 'West Bottom'). The Finnish name of Österbotten, (, meaning 'land'), gives a hint as to the meaning in both languages: the meaning of includes both 'bottom' and 'north'. is the base word for north, , with an adjectival suffix adde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-glacial Rebound
Post-glacial rebound (also called isostatic rebound or crustal rebound) is the rise of land masses after the removal of the huge weight of ice sheets during the last glacial period, which had caused isostatic depression. Post-glacial rebound and isostatic depression are phases of glacial isostasy (glacial isostatic adjustment, glacioisostasy), the deformation of the Earth's crust in response to changes in ice mass distribution. The direct raising effects of post-glacial rebound are readily apparent in parts of Northern Eurasia, Northern America, Patagonia, and Antarctica. However, through the processes of ''ocean siphoning'' and ''continental levering'', the effects of post-glacial rebound on sea level are felt globally far from the locations of current and former ice sheets.Milne, G.A., and J.X. Mitrovica (2008) ''Searching for eustasy in deglacial sea-level histories.'' Quaternary Science Reviews. 27:2292–2302. Overview During the last glacial period, much of northern Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
