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.

Baltic Sea map
Map of the Baltic Sea, showing the Gulf of Bothnia in the upper half
Scandinavia M2002074 lrg
Satellite image of Fennoscandia in winter. The northern part of the Gulf of Bothnia, the Bothnian Bay, is covered with sea ice.


Bothnia is a latinization. The Swedish name "Bottenviken" was originally just "Botn(en)" with botn being Old Norse for "gulf" or "bay";[1] which is also the meaning of the second element "vik".

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: the meaning of pohja includes both "bottom" and "north." Pohja (bottom) is the base word for north, pohjoinen, with an adjectival suffix added.[2]

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).

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 Proto-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 Proto-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 "entrance room/hall" and 'etelä', "South". According to Lönnrot, north was viewed as the bottom direction because the lowest point of the sun's path is there.


The International Hydrographic Organization defines the southern limit of the Gulf of Bothnia as follows:[3]

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 the Aland islands and adjacent shoals and channels in the Gulf of Bothnia.

Solis Occasus in Sino Bothnico
June 2006 view of the Gulf of Bothnia in Finland.

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. its coordinates are 65° 54'07" N 22° 39'00 E.[4]

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 the continental ice during last ice age. The rise is 80 cm every hundred years.[5]

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,[6] from 0.4% near Kvarken to 0.2% in the northernmost part[7], that many freshwater fish such as the pike, whitefish and perch thrive in it.[5]

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.[8]


Geologically the Gulf of Bothnia is an ancient depression of tectonic origin. The depression in 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.[9]

Ongoing post-glacial rebound is thought to result in splitting of the Gulf of Bothnia into a southern gulf and northern lake across the Norra Kvarken area in about 2,000 years.[10]


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. 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.[11] 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.[12] In the Gulf of Bothnia, icebreakers assist the ports needed in average half a year, when the Gulf of Finland, the season is only three months.[13]

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.




  1. ^ Svensk etymologisk ordbok / (in Swedish)
  2. ^ "suomen kielisten ilmansuuntien etymologia". 26 July 2006. Retrieved 18 November 2016.
  3. ^ "Limits of Oceans and Seas, 3rd edition" (PDF). International Hydrographic Organization. 1953. Retrieved 6 February 2010.
  4. ^ "Töre båthamn". hamnar i Kalix (in Swedish). Retrieved 1 December 2015.
  5. ^ a b "About the Bay of Bothnia". Bottenvikens Skargård. Archived from the original on 5 October 2013. Retrieved 1 December 2015.
  6. ^ "Gulf of Bothnia". Archived at the Wayback Machine. Archived from the original on 10 March 2007.
  7. ^ "Perämeren erityispiirteet". Archived from the original on 2012-01-21.
  8. ^ Typical restrictions to navigation 1994/95-2003/04 (pdf) Archived 1 December 2015 at the Wayback Machine
  9. ^ Lidmar-Bergström, Karna (1997). "A long-term perspective on glacial erosion". Earth Surface Processes and Landforms. 22: 297–306.
  10. ^ Tikkanen, Matti; Oksanen, Juha (2002). "Late Weichselian and Holocene shore displacement history of the Baltic Sea in Finland". Fennia. 180 (1–2). Retrieved December 22, 2017.
  11. ^ "Table 4. Statistics on international shipping 2014" (PDF). Statistics from the Finnish Transport Agency. Retrieved 1 December 2015.
  12. ^ Havsplanering p. 92 (in Swedish)
  13. ^ "Climate change creates new prerequisites for shipping". Climate Guide. SYKE, Aalto University, YTK & Finnish Met. Institute. Retrieved 1 December 2015.

External links

Coordinates: 63°N 20°E / 63°N 20°E

Baltic Sea

The Baltic Sea is a marginal sea of the Atlantic Ocean, enclosed by Denmark, Estonia, Finland, Latvia, Lithuania, Sweden, northeast Germany, Poland, Russia and the North and Central European Plain.

The sea stretches from 53°N to 66°N latitude and from 10°E to 30°E longitude. A mediterranean sea of the Atlantic, with limited water exchange between the two bodies, the Baltic Sea drains through the Danish islands into the Kattegat by way of the straits of Øresund, the Great Belt, and the Little Belt. It includes the Gulf of Bothnia, the Bay of Bothnia, the Gulf of Finland, the Gulf of Riga, and the Bay of Gdańsk.

The Baltic Proper is bordered on its northern edge, at the latitude 60°N, by the Åland islands and the Gulf of Bothnia, on its northeastern edge by the Gulf of Finland, on its eastern edge by the Gulf of Riga, and in the west by the Swedish part of the southern Scandinavian Peninsula.

The Baltic Sea is connected by artificial waterways to the White Sea via the White Sea Canal and to the German Bight of the North Sea via the Kiel Canal.

Bothnian Bay

The Bothnian Bay or Bay of Bothnia (Swedish: Bottenviken, Finnish: Perämeri) is the northernmost part of the Gulf of Bothnia, which is in turn the northern part of the Baltic Sea. The land holding the bay is still rising after the weight of ice-age glaciers has been removed, and within 2,000 years the bay will be a large freshwater lake. The bay today is fed by several large rivers, and is relatively unaffected by tides, so has low salinity. It freezes each year for up to six months. Compared to other parts of the Baltic it has little plant or animal life.

Bothnian Sea

The Bothnian Sea (Swedish: Bottenhavet, Finnish: Selkämeri) links the Bothnian Bay (also called the Bay of Bothnia) with the Baltic proper. Kvarken is situated between the two. Together, the Bothnian Sea and Bay make up a larger geographical entity, the Gulf of Bothnia, where the Bothnian Sea is the southern part. The whole Gulf of Bothnia is situated between Sweden, to the West, Finland, to the East, and the Sea of Åland and Archipelago Sea to the South. The surface area of Bothnian Sea is approximately 79,000 km². The largest coastal towns, from south to north, are Rauma and Pori in Finland, and Gävle and Sundsvall in Sweden. Umeå (Sweden) and Vaasa (Finland) lie in the extreme north, near Bothnian Bay.

Bothnian Sea National Park

Bothnian Sea National Park (Finnish: Selkämeren kansallispuisto, Swedish: Bottenhavets nationalpark) is a national park in Finland. It was established in early 2011. Around 98% of the surface of the National Park consists of water.


In Norse mythology, Gandvik is a dangerous sea, known as "Bay of Serpents" because of its tortuous shape. Saxo Grammaticus stated that Gandvik was an old name for the Baltic Sea (a name misspelt Grandvik in some translations). The legend presumably refers to Gulf of Bothnia. However, there are two opposite theories about where Gandvik was situated, based on the 1323 Treaty of Nöteborg: in the Arctic Ocean or the Gulf of Bothnia. Starting from the 1850s, the former received more support in that Sweden had extended far out to the Arctic Ocean, but since the 1920s the latter have gained more support. However, Hversu Noregr byggðist, dating from the former part of the 13th century, is by most opinions referring to the White Sea when it uses the term Gandvik.


Gästrikland is a historical province or landskap on the eastern coast of Sweden. It borders Uppland, Västmanland, Dalarna, Hälsingland and the Gulf of Bothnia. Gästrikland is the southernmost of the Norrland provinces.

Other used forms of the name is Gestricia, Gastrikland. Before 1900, the spelling was officially Gestrikland in Swedish.


Haukipudas is a town and former municipality of Finland. It is located in the province of Oulu and part of the Northern Ostrobothnia region. Its shore runs along the Gulf of Bothnia, with the river Kiiminkijoki running through the province. Along with Kiiminki, Oulunsalo and Yli-Ii municipalities it was merged with the city of Oulu on 1 January 2013.

The municipality had a population of 19,053 (31 December 2012) and covered an area of 1,023.62 km2 (395.22 sq mi) of which 224.95 km2 (86.85 sq mi) is water. The population density is 23.8559/km2 (61.7865/sq mi).

The municipality was unilingually Finnish.There were 16 villages in Haukipudas: Kirkonkylä, Santaholma, Ukonkaivos, Martinniemi, Asemakylä, Onkamo, Halosenniemi, Holstinmäki, Häyrysenniemi, Jokikylä, Kalimeenkylä, Kello, Kiviniemi, Parkumäki, Takkuranta and Virpiniemi.

The educational department took part in Lifelong Learning Programme 2007–2013 in Finland.


Hälsingland (Swedish pronunciation: [ˈhɛlːsɪŋland] (listen)), sometimes referred to as Helsingia in English, is a historical province or landskap in central Sweden. It borders Gästrikland, Dalarna, Härjedalen, Medelpad and the Gulf of Bothnia. It is part of the land of Norrland.

Keskiniemi beacon tower

The Keskiniemi beacon tower (Keskiniemen tunnusmajakka in Finnish), often referred to as the Karvo beacon tower, is a historic daymark located on a promontory of Keskiniemi in the northwestern part of Hailuoto island in the Gulf of Bothnia in Finland. The tower was built in 1858 to alert the vessels about sandbars reaching northwest from the site. It is the oldest surviving navigational aid on Hailuoto island. The tower has structural similarities with the Härkmeri beacon tower built in 1857.The wooden tower has a six-metre (20 ft) high square base with a square pyramidical top. The first floor houses a 70 cm (​2 1⁄3 feet) thick layer of stones serving as a counterweight to prevent the structure from tipping in wind. The structure also has wooden beams in all four corners for increased support against winds. The tower has a wooden top ornament.The structure measures 18,9 meters (62 ft) high from the ground, with the top being 20,9 meters (87 ft) above sea level. All of its faces are white.The current beacon tower is the second navigational aid located on the Keskiniemi promontory. In a navigational map dated on 1785 by Henrik Wacklin a beacon tower is shown at the same location.The tower has never been lit. A modern Keskiniemi sector light has been erected alongside the tower.


Kvarken (Swedish Kvarken or Norra Kvarken (as opposed to South Kvarken), Finnish Merenkurkku lit. "throat of the sea") is the narrow region in the Gulf of Bothnia separating the Bothnian Bay (the inner part of the gulf) from the Bothnian Sea. The distance from Swedish mainland to Finnish mainland is around 80 km (50 mi) while the distance between the outmost islands is only 25 km (16 mi). The water depth in the Kvarken region is only around 25 metres (82 ft). The region also has an unusual rate of land rising at about 10 mm (0.39 inches) a year.

On the Finnish side of Kvarken, there is a large archipelago, the Kvarken Archipelago, which includes the large islands Replot, Björkö and a large number of smaller islands. Most of it is belongs to the municipality of Korsholm. Most of the small islands are inhabited. The archipelago is smaller on the Swedish side of the region, and the islands have much steeper shores. The Kvarken region was historically important also, because mail was delivered across Kvarken when the sea was completely frozen from the Swedish to the Finnish coast. This mail route was used frequently during the period of Swedish rule.

In the group of islands in the “middle” of the Kvarken region, in Swedish called Valsörarna – Finnish Valassaaret, is a 36-metre-high (118 ft) lighthouse designed by Henry Lepaute who worked for Gustave Eiffel's engineering bureau. The structural similarity between the lighthouse (built in 1885) and the Eiffel tower (built in 1889) is quite obvious. The lighthouse is now automated as are most lighthouses in Finland.

Several attempts to cross the strait swimming have been made but cold water and currents have usually been insurmountable obstacle. The first successful attempt was carried out by Lennart Flygare, Pavio Grzelewski and Tore Klingberg, who on the 24:th of July 2018 swam from Valassaaret (Valsörarna) on the Finnish side to Holmögadd in Sweden. It took them 12 hours 2 minutes to cross the strait.

List of companies of Åland

The Åland Islands are an archipelago at the entrance to the Gulf of Bothnia in the Baltic Sea belonging to Finland. Åland's economy is heavily dominated by shipping, trade and tourism. Shipping represents about 40% of the economy, with several international carriers owned and operated off Åland. Most companies aside from shipping are small, with fewer than ten employees. Farming and fishing are important in combination with the food industry. According to Eurostat, in 2006 Åland was the 20th wealthiest of the EU's 268 regions, and the wealthiest in Finland, with a GDP per inhabitant 47% above the EU mean.

List of lighthouses and lightvessels in Finland

This is a list of lighthouses and lightvessels in Finland.

List of rivers of Finland

This is a list of rivers of Finland. Listing begins with rivers flowing into the Baltic sea, from the north, that is from the Swedish border. Tributaries are listed down the page in an upstream direction.

Water flows from Finland directly to the Baltic Sea, which is divided here into the Gulf of Bothnia and Gulf of Finland, and the Archipelago Sea between them. Some rivers flow to Russia, ending either to Gulf of Finland or to the White Sea, and a few to the Arctic Ocean through Russia or Norway.

There are a lot of lakes in Finland and so this listing includes also several lakes through which the rivers flow or begin from. Due to the great number of lakes especially in the Finnish Lakeland, where watercources tend to consist of chains of lakes rather than long rivers, some rivers with a large catchment area can also be quite short or there may only be a short rapid between large lakes, like for example Tammerkoski in Tampere.


Ljusdal (Swedish: [²jʉːsdɑːl]) is a locality and the seat of Ljusdal Municipality, Gävleborg County, Sweden with 6,230 inhabitants in 2010.Ljusdal is located beside the river Ljusnan which goes from Bruksvallarna to the Gulf of Bothnia.

Ljusdal is famous for having hosted the annual Bandy World Cup in the sport of bandy from 1974 to 2008.

Three Hälsingland Farmhouses situated in Ljusdal Municipality were inscribed in 2012 on the UNESCO list of World Heritage Sites.

Marjaniemi Lighthouse

Marjaniemi Lighthouse (Finnish: Marjaniemen majakka) is a lighthouse located in the village of Marjaniemi at the westernmost point of Hailuoto island on the Gulf of Bothnia. The lighthouse is located approximately 50 kilometres (31 mi) west of Oulu. The lighthouse was designed by Axel Hampus Dalström as his fourth lighthouse and it was first lit in 1872.The tower is brick masonry, and has 110 steps inside with no intermediate floors. Originally the light was equipped with a Fresnel lens system, and it displayed a white light towards a sector clockwise from south to northeast. There were two lighthouse keepers and a master until 1962 when the lighthouse was automated. A pilot station was built next to the tower, currently the pilot station serves as a hotel.

The lighthouse also houses a smaller sector light that is used to guide vessels to and from the fishing harbour. Today the lighthouse also houses a webcam.


Medelpad (Listen ) is a historical province or landskap in the north of Sweden. It borders Hälsingland, Härjedalen, Jämtland, Ångermanland and the Gulf of Bothnia.

The province is a part of Norrland and as such considered to be Northern Sweden, although the province geographically is located in the middle of Sweden. It is a common misconception that the name "Medelpad" ("middle land" or "middle ground") reflects this, but the name actually refers to the fact that most of the province lies between its two rivers Ljungan and Indalsälven.

Sea of Åland

The Sea of Åland (Finnish: Ahvenanmeri; Swedish: Ålands hav) is a waterway in the southern Gulf of Bothnia, between the Åland islands and Sweden. It connects the Bothnian Sea with the Baltic Sea proper. The seas are often choppy here. The narrowest part is named South Kvarken. The trench running on the bottom of the Sea of Åland contains the second-deepest spot of the Baltic Sea, at a depth of 301 meters, which is second only to Landsort Deep.

Many ferries moving between Finland and Sweden cross the Sea of Åland.

South Kvarken

South kvarken (Finnish: Ahvenanrauma, Swedish: Södra Kvarken) is the narrowest stretch of sea between Finnish Åland and Sweden, forming a strait connecting the Sea of Åland and the Bothnian Sea of approximately 30 km (18.5 mi) across.

Västerbotten County

Västerbotten County (Västerbottens län) is a county or län in the north of Sweden. It borders the counties of Västernorrland, Jämtland, and Norrbotten, as well as the Norwegian county of Nordland and the Gulf of Bothnia.

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