Gulf of Bothnia
The Gulf of Bothnia (Finnish: Pohjanlahti; Swedish: Bottniska viken, i.e. Bottenviken + Bottenhavet) is the northernmost arm of the Baltic Sea. It is situated between Finland's west coast and Sweden's east coast. In the south of the gulf lie the Åland Islands, between the Sea of Åland and the Archipelago Sea.
The name botn was applied to the Gulf of Bothnia as Helsingjabotn in Old Norse, after Hälsingland, which at the time referred to the coastland west of the gulf. Later, botten was applied to the regions Västerbotten on the western side and Österbotten the eastern side ("East Bottom" and "West Bottom"). The Finnish name of Österbotten, Pohjanmaa, or "Pohja"-land, gives a hint as to the meaning in both languages: pohja means both "bottom" and "north."
Botn/botten 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).[clarification needed]
A second possibility is that botten follows an alternative Scandinavian connotation of 'furthermost'. Thus, the Gulf of Bothnia would be the farthest extent of the Ocean.
Julius Pokorny gives the extended Indo-European root as *bhudh-m(e)n with a *bhudh-no- variant, from which the Latin fundus, as in fundament, is derived. The original meaning of English north, from Indo-European *ner- "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.
The origin of the word is indeed very ancient, belonging to a period before the world discoveries by the Portuguese. Until then, North was not seen as the magnetic top of the world, East being the normal orientation of a map.
Also, 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 'Pohja' in its use as "North". Deriving as well from this logic is the affinity in the Finnish language of the words 'eteinen', meaning "hall" and 'Etelä', "South".
From Simpnäsklubb (59°54'N) in Sweden, to Flötjan, Lagskær, Fæstörne, Kökarsörn, and Vænö-Kalkskær to the SW point of Hangöudde (Hangö Head, 59°49'N) in Finland, thus including the Aland islands and adjacent shoals and channels in the Gulf of Bothnia.
Geophysical data 
The gulf is 725 km (450 mi) long, 80–240 km (50-150 mi) wide and has an average depth of 60 m (200 ft, 33 fathoms). The maximum depth is 295 m (965 ft, 161 fathoms). The surface area is 117,000 km² (45,200 sq mi). The northernmost point is situated in Töre in the Bothnian Bay.
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, from 0.4% near Kvarken to 0.2% in the northernmost part, that one can no longer taste the salt in the water and many freshwater fish thrive in it.
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 ice breaker 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.
Geological history 
For the geological history of the entire region, refer to the Baltic Sea.
Some historians suggest that the adventurer Ottar was referring to the Gulf of Bothnia when he spoke of the Kven Sea in the 9th century. It is also possible that Claudius Clavus's usage of the term Mare Gotticus in the 15th century refers to the Gulf of Bothnia.
The land surrounding the Gulf of Bothnia is heavily forested. Trees are logged, then transported to the coast for milling.
|Wikimedia Commons has media related to: Gulf of Bothnia|
- "Limits of Oceans and Seas, 3rd edition". International Hydrographic Organization. 1953. Retrieved 6 February 2010.
- Perämeren erityispiirteitä
- Typical restrictions to navigation 1994/95-2003/04 (pdf)