Gulf of Bothnia

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The Gulf of Bothnia (Template:IPAc-en, Template:Langx, Finnish and Template:Langx) is divided into the Bothnian Bay, the (North) Kvarken and the Bothnian Sea, and it is the northernmost arm of the Baltic Sea, between Finland's west coast (Ostrobothnia (East Bothnia)) and the northern part of Sweden's east coast (Västerbotten (Westrobothnia, West Bothnia) and Norrbotten (North Bothnia)). In the south of the gulf lies Åland, between the Sea of Åland and the Archipelago Sea.

Name

Template:More citations needed Bothnia is a latinization. The Swedish name Template:Lang was originally just Template:Lang, with Template:Lang being Old Norse for "gulf" or "bay",<ref>Svensk etymologisk ordbok / Template:In lang</ref> which is also the meaning of the second element Template:Lang.

The name Template:Lang was applied to the Gulf of Bothnia as Template:Lang in Old Norse, after Template:Lang, which at the time referred to the coastland west of the gulf. Later, Template:Lang was applied to the regions of Template:Lang on the western side and Template:Lang on the eastern side ('West Bottom' and 'East Bottom'). The Finnish name of Österbotten, Template:Lang (Template:Lang, meaning 'land'), hint as to the meaning in both languages: the meaning of Template:Lang includes both 'bottom' and 'north'. Template:Lang is the base word for north, Template:Lang, with an adjectival suffix added.<ref>Template:Cite web</ref>

Template:Lang/Template:Lang is cognate with the English word bottom, and it might be part of a general north European distinction of lowlands, as opposed to highlands, such as the Netherlandic region, Samogitia (Lithuanian), and Sambia (Russia).Template:Clarify

Julius Pokorny gives the extended Proto-Indo-European root as Template:Lang with a Template:Lang variant, from which the Latin Template:Lang, as in fundament, is derived. The original meaning of English north, from Proto-Indo-European Template:Lang 'under', indicates an original sense of 'lowlands' for bottomlands. On the other hand, by north the classical authors usually meant 'outermost', as the northern lands were outermost to them. In Saami, the cardinal directions were named according to the different parts of the typical tent used by this nomadic people. The door of the tent was traditionally pointed south, in the most sunny direction, and the bottom of the tent would be aligned with the north. Thus the origin of the word Template:Lang in its use as 'north'. According to Elias Lönnrot, north was viewed as the bottom direction because the lowest point of the sun's path is there.

Geography

The International Hydrographic Organization defines the southern limit of the Gulf of Bothnia as follows:<ref>Template:Cite web</ref>

From Simpnäsklubb (59°54'N) in Sweden, to Flötjan, Lagskær [sic], Fæstörne [sic], Kökarsörn, and Vænö-Kalkskær [sic] to the SW point of Hangöudde (Hangö Head, 59°49'N) in Finland, thus including Åland and adjacent shoals and channels in the Gulf of Bothnia.

Sandy beaches of Kalajoki at the shores of the Gulf of Bothnia

The gulf is Template:Convert long, Template:Convert wide and has an average depth of Template:Convert. The maximum depth is Template:Convert. The surface area is Template:Convert. The northernmost point is situated in Töre in the Bothnian Bay. its coordinates are 65° 54'07" N 22° 39'00 E.<ref>Template:Cite web</ref>

The depth and surface area of the Gulf of Bothnia are constantly decreasing, as the land is rising after it had been pressed down by about Template:Convert<ref name="ReferenceA">Geologica: Earth’s Dynamic Forces by Dr Robert R. Coenraads and John I. Koivula</ref> by the continental ice during last ice age. The rise is 80 cm every hundred years.<ref name="BOTTEN">Template:Cite web</ref> It is estimated that the land has a further Template:Convert to rise before equilibrium is reached. This recovery rate will progressively slow as isostatic equilibrium is approached.<ref name="ReferenceA"/>

Into the gulf flow a number of rivers from both sides; consequently, a salinity gradient exists from north to south. In the south the water is the normal brackish water of the Baltic Sea, but in the north, in the Bothnian Bay, the salinity is so low,<ref>Template:Cite web</ref> from 0.4% near Kvarken to 0.2% in the northernmost part,<ref>Template:Cite web</ref> that many freshwater fish such as the pike, whitefish and perch thrive in it.<ref name="BOTTEN"/>

The gulf is a combination of the Bothnian Bay in the north and the Bothnian Sea in the south, separated by the Kvarken region with a water depth of around Template:Convert and a rate of land rising of almost Template:Convert a year. Within 2000 years the bay is expected to separate from the rest of the gulf and become a freshwater lake.

Being nearly fresh, the gulf is frozen over five months every year. The icing of the Baltic Sea begins and ends in the northern Gulf of Bothnia. Traffic restrictions for icebreaker assistance are typically in force for all the gulf from late January to late April and for the northernmost ports from the middle of December to the middle of May.<ref>Typical restrictions to navigation 1994/95-2003/04 (pdf) Template:Webarchive</ref>

Geology

Template:Further Geologically the Gulf of Bothnia is an ancient depression of tectonic origin. The depression is partly filled with sedimentary rock deposited in the Precambrian and Paleozoic. Nearby plains adjoining the gulf are part of the Sub-Cambrian peneplain. While being repeatedly covered by glaciers during the last 2.5 million years glacial erosion has had a limited effect in changing the topography.<ref>Template:Cite journal</ref>

It is estimated that within about 2,000 years, ongoing post-glacial rebound will raise the seafloor in the Norra Kvarken area above water, splitting the Gulf of Bothnia into a southern gulf and northern lake.<ref>Template:Cite journal</ref>

History

The gulf was not known by ancient and medieval geographers and as late as in 1427 not indicated by the Danish cartographer Claudius Clavus, not even in the map of Hartmann Schedel, printed in 1493. The first map in which the gulf has been delineated, although without name, is that of Nicolaus Germanus from the year 1482.<ref>Erkki Fredrikson: Suomi 500 vuotta Euroopan kartalla. Gummerus, 2005. Pages 12-16, Template:ISBN</ref>

Economy

Template:More citations needed The land surrounding the Gulf of Bothnia is heavily forested. Trees are logged, then transported to the coast for milling. The gulf is also important for oil transport to the coastal cities and ore transport to steel mills, for instance in Raahe.

In terms of tonnage in international traffic, the largest ports on the Finnish side are Rauma, Kokkola and Tornio.<ref>Template:Cite web</ref> The main ports of the Swedish side are in Luleå, Skellefteå, Umeå, Sundsvall, Gävle and Hargshamn. In Luleå, iron ore pellets are exported and coal is imported. Gävle is Sweden's third-largest container port. It also ships forest products and oil.<ref>Havsplanering p. 92 Template:In lang</ref> The only regular cruiseferry route across the Gulf of Bothnia is the Wasaline service between Umeå and Vaasa.

In port operations in the Gulf of Bothnia, icebreaker assistance can be required for an ice season that averages as long as six months; whereas in the Gulf of Finland, the icebreaking season averages only three months.<ref>Template:Cite web</ref>

There is some fishery, mainly Baltic herring, for domestic needs. A persistent problem has been pollution, because the sea is enclosed by a large drainage basin and is poorly connected to fresher waters from the Atlantic. Mercury and PCB levels have been relatively high, although the Finnish Food Safety Authority considers the herring edible. Although the levels exceed the limits, the fatty acids have health benefits that offset this risk.