View source for Kvarken

{{short description|Region of the Gulf of Bothnia separating the Bothnian Bay from the Bothnian Sea}}
{{Infobox body of water
| name               = Kvarken
| native_name        = 
| native_name_lang   = 
| other_name         = Norra Kvarken, Merenkurkku
<!--    Images     -->
| image              = Svedjehamn panorama sett från utsiktstornet Saltkaret.jpg
| alt                = Refer to caption
| caption            = View over Kvarken from Svedjehamn, [[Björkö (Korsholm)|Björkö]], Finland
| image_bathymetry   = Kvarken.png
| alt_bathymetry     = Map showing the location of Kvarken in the Gulf of Bothnia
| bathymetry_size    = 220px
| caption_bathymetry = 
<!--    Stats      -->
| location           = [[Finland]], [[Sweden]]
| coordinates        = {{coord|format=dms|region:SV_type:waterbody|display=inline,title}}
| type               = [[strait]]
| etymology          = 
| part_of            = [[Gulf of Bothnia]]
| inflow             = 
| rivers             = 
| catchment          = 
| length             = N-S: {{convert|60|km|abbr=on}}<ref name = "nominate"/>
| width              = E-W: {{convert|70|km|abbr=on}}<ref name = "nominate"/>
| area               = 
| depth              = 
| max-depth          = {{convert|25|m|abbr=on}}<ref name = "nominate"/>
| volume             = 
| salinity           = 4
| temperature_high   = {{convert|16|C|abbr=on}}<ref name = "nominate"/>
| temperature_low    = {{convert|0|C|abbr=on}}<ref name = "nominate"/>
| frozen             = 
| islands            = 6,550<ref name = "nominate"/>
| islands_category   = 
<!--   Below       -->  
| website            = 
| reference          = 
}}

'''Kvarken''' ({{langx|sv|Kvarken, Norra Kvarken}} (as opposed to [[South Kvarken]]); {{Langx|fi|Merenkurkku|lit=throat of the sea}}) is the narrow region of the [[Gulf of Bothnia]] separating the [[Bothnian Bay]] (the inner part of the gulf) from the [[Bothnian Sea]]. The distance from the [[Sweden|Swedish mainland]] to the [[Mainland Finland|Finnish mainland]] is around {{convert|80|km|mi|abbr=on}}, while the distance between the outermost islands is only {{convert|25|km|mi|abbr=on}}. The water depth in the Kvarken region is only around {{convert|25|m|ft|0|abbr=out}}. The region also has an unusual rate of [[Post-glacial rebound|land rising]] at almost {{convert|10|mm|2|abbr=in}} a year.<ref name = "nominate">{{cite report |title = The Kvarken Archipelago |work=WHC Nomination Documentation |url = http://whc.unesco.org/uploads/nominations/898bis.pdf |author = Metsähallitus (Forest and Park Services) |date = 16 July 2006 |access-date = 3 October 2021}}</ref>

Several attempts to cross the strait swimming have been made, but cold water and currents have usually been insurmountable obstacles. The first successful crossing was carried out by Lennart Flygare, Pavio Grzelewski and Tore Klingberg, who on 24 July, 2018, swam from Valassaaret ([[Valsörarna]]) on the Finnish side to [[Holmöarna]] in Sweden. It took them 12 hours 2 minutes to cross the strait.<ref>{{Cite news|url=https://www.vk.se/plus/2432049/de-simmade-26-kilometer-over-kvarken|title=De simmade 26 kilometer over kvarken|last=Krainer|first=Patrick|date=2018-07-25|work=Västerbottenskuriren|access-date=2018-09-03}}</ref>

==Kvarken Archipelago==
{{Infobox UNESCO World Heritage Site
| WHS           = Kvarken Archipelago
| image         = Kvarken Archipelago Finland.png
| image_upright = 1.2
| caption       = Kvarken Archipelago in Finland
| location      = [[Gulf of Bothnia]], [[Finland]]
| part_of       = [[High Coast]] / Kvarken Archipelago
| includes      = {{flatlist|
* 002: Zone A
* 003: Zone B}}
| criteria      = {{UNESCO WHS type|(viii)}}(viii)
| ID            = 898bis
| coordinates   = {{coord|63|18|N|21|18|E|format=dms}}
| year          = 2000
| extension     = 2006
| area          = {{convert|194,400|ha|sqmi|abbr=on}}
| website       = http://www.kvarken.fi
}}

On the Finnish side of Kvarken, there is a large [[archipelago]], the Kvarken Archipelago, which includes the large islands [[Replot]], [[Björkö (Korsholm)|Björkö]] and over 5,600 smaller islands.<ref name = "unesco">{{cite web |url = http://whc.unesco.org/en/list/898/ |title = High Coast/Kvarken Archipelago |website = UNESCO World Heritage Centre |publisher = United Nations Educational, Scientific, and Cultural Organization |access-date = 3 October 2021}}</ref> Most of it 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, part of [[Umeå Municipality]], 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 when [[Finland]] was a part of [[Sweden]].

During the [[Ice age|Ice Ages]], the Kvarken region was located underneath the [[Weichselian glaciation|Fennoscandian ice sheet]].<ref name = "unesco"/> When the ice sheet retreated from the area around 9,600 years ago, the land, which had been compacted under the weight of the ice, rapidly expanded in a process known as [[isostatic rebound]].<ref name = "unesco"/> The Kvarken region is known for having some of the fastest rates of this uplift on Earth, having risen 285 meters since glacial retreat. It continues to rise, demonstrating the effects of deglaciation on flat and shallow archipelagos.<ref name = "nominate"/> The Kvarken Archipelago is also notable for its unique [[moraine]] formations (called de Geer moraines), which form regular clusters that are parallel to the ice front.<ref name = "nominate"/> It is estimated that within about 2,000 years, the seafloor in this area will rise above water, splitting the Gulf of Bothnia into a southern gulf and northern lake.<ref>{{cite journal |last1=Tikkanen |first1=Matti |last2=Oksanen |first2=Juha |date=2002 |title=Late Weichselian and Holocene shore displacement history of the Baltic Sea in Finland |url=http://www.helsinki.fi/maantiede/geofi/fennia/demo/pages/oksanen.htm |journal=[[Fennia (journal)|Fennia]] |volume=180 |issue=1–2 |access-date=22 December 2017 }}</ref>

In 2006, parts of the Kvarken Archipelago were added as an extension to the [[World Heritage Site]] of the [[High Coast]] (located on the western shore of the Gulf of Bothnia) in [[Sweden]], because of its outstanding demonstration of isostatic uplift, and the influence of glacial retreat on the evolution of landforms and topography.<ref name = "unesco"/> The most Finnish parts of the High Coast/Kvarken Archipelago World Heritage Site are situated in the [[Korsholm]] municipality.

In the group of islands in the “middle” of the Kvarken region, in Swedish called [[Valsörarna]] &ndash; Finnish ''Valassaaret'', is a {{convert|36|m|ft|adj=mid|-high}} lighthouse designed by {{ill|Henry Lepaute|fr}} 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.

== Transportation ==
The ferry route between [[Umeå]] and [[Vaasa]] connects Sweden and Finland at the narrowest part of the Gulf of Bothnia. The route is currently operated by [[Wasa Line|Wasaline]].

==Bridge==
{{main|Kvarken Bridge}}
There have been proposals for a bridge across the strait, at a cost of about 1.5&nbsp;to 2&nbsp;billion&nbsp;[[euro]]s. There are islands in the strait, and the sum of the lengths of the probably three bridge parts would be about {{convert|40|km|mi|abbr=on}}. The Swedish minister of finance has said it is an interesting idea, but the idea is still decades from being brought to fruition. There is a debate in the coastal cities on both sides, like [[Umeå]] and [[Vaasa]]. The official view from the Swedish and Finnish governments is that it is much too expensive, also put in regard that the cities are very small by European standards, as compared to [[Copenhagen]] and [[Malmö]] between the [[Oresund fixed link]]. The natural values{{which?|date=July 2022}} of the area also make a bridge dubious.

==References==
{{reflist}}

==External links==
{{commons category|Kvarken}}
{{wikivoyage|Kvarken Archipelago}}
*[https://highcoastkvarken.org/ High Coast/Kvarken Archipelago World Heritage Site's official website]
*[http://www.kvarkenworldheritage.fi/ Kvarken World Heritage Site]
*[https://whc.unesco.org/en/list/898 UNESCO World Heritage profile]
*"[http://www.bbc.com/travel/story/20170414-the-black-islands-rising-from-the-sea The black islands rising from the sea]", ''BBC Travel'', 14 April 2017. Retrieved 20 April 2017.

{{World Heritage Sites in Finland}}

[[Category:Straits of Finland]]
[[Category:Straits of Sweden]]
[[Category:World Heritage Sites in Finland]]
[[Category:Landmarks in Finland]]
[[Category:Finland–Sweden border]]
[[Category:International straits]]
[[Category:Landforms of Norrbotten County]]
[[Category:Landforms of Västerbotten County]]
[[Category:Landforms of Ostrobothnia (administrative region)]]