Märket ('The Mark', ) is a uninhabited

skerry A skerry ( ) is a small rocky island, or islet, usually too small for human habitation. It may simply be a rocky reef. A skerry can also be called a low stack (geology), sea stack. A skerry may have vegetative life such as moss and small, ...

in the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

shared by

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

and

Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...

(in the area of the autonomous region

Åland Åland ( , ; ) is an Federacy, autonomous and Demilitarized zone, demilitarised region of Finland. Receiving its autonomy by a 1920 decision of the League of Nations, it is the smallest region of Finland by both area () and population (30,54 ...

), with a

lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Ligh ...

as its salient humanmade feature. Märket has been divided between the two countries since the

Treaty of Fredrikshamn The Treaty of Fredrikshamn, or the Treaty of Hamina, was a peace treaty concluded between Sweden and Imperial Russia on 17 September 1809. The treaty concluded the Finnish War and was signed in the Finnish town of Fredrikshamn ( Hamina). Russia ...

of 1809 defined the border between Sweden and

Grand Duchy of Finland The Grand Duchy of Finland was the predecessor state of modern Finland. It existed from 1809 to 1917 as an Autonomous region, autonomous state within the Russian Empire. Originating in the 16th century as a titular grand duchy held by the Monarc ...

as going through the middle of the island. The Finnish side of the island is part of the Municipality of Hammarland in the autonomous region of

and is the westernmost land point of Finland. The Swedish part of the island is itself divided by two

counties of Sweden The counties of Sweden () are the first-level administrative subdivisions of Sweden. There are twenty-one counties; however, the number of counties has varied over time, due to territorial changes and to divisions or mergers of existing counti ...

Uppsala County Uppsala County () is a county or '' län'' on the eastern coast of Sweden, whose capital is the city of Uppsala. It borders the counties of Dalarna, Stockholm, Södermanland, Västmanland, Gävleborg, and the Baltic Sea. Province The nor ...

(

Östhammar Municipality Östhammar Municipality () is a municipalities of Sweden, municipality in Uppsala County in east central Sweden. Its seat is located in the city status in Sweden, city of Östhammar. The present municipality was created during the local governmen ...

) and Stockholm County (

Norrtälje Municipality Norrtälje Municipality () is a municipalities of Sweden, municipality in Stockholm County in east central Sweden. Its seat is located in the stad (Sweden), city of Norrtälje. It is the largest and northernmost municipality of Stockholm County a ...

Geography and history

The '' Understen–Märket Passage'' links the

Bothnian Sea The Bothnian Sea (; ) links the Bothnian Bay (also called the Bay of Bothnia) with the Baltic Sea, Baltic proper. Kvarken is situated between the two. Together, the Bothnian Sea and Bay make up a larger geographical entity, the Gulf of Bothnia, ...

to the Baltic proper. The skerry is roughly long by wide, and has an area of about . The island is gaining height due to

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 an ...

, and was probably underwater before the 1500s. Märket is the smallest sea island shared by two countries. It used to have a straight border until the Grand Duchy of Finland built the lighthouse on the Swedish side and then, they had to change the border. The name ''Märket'' ('the Mark') probably comes from its usefulness as a navigation mark before there were lighthouses. The route between Sweden and Åland has a passage about long over open sea. Before the lighthouse was erected, the island and its shallows were dangerous navigational hazards, which seafarers tried desperately to avoid. In 1873, as many as 23 ships were grounded on the Swedish coast and its

archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...

trying to avoid Märket, and eight of them were shipwrecked.Tom Backmansson, 1998. TV series "Fyren - Majakka", episode 10: Märket. First shown on Yle TV1, 16 July 2000 17.59. Produced by Yleisradio Oy, http://areena.yle.fi/1-682613 https://www.youtube.com/watch?v=ytNqj9QfG70 Märket is detached from the main Åland archipelago, with the closest island more than away, and the closest harbor, Berghamn, away in

Eckerö Eckerö is a municipality of Åland, an autonomous territory under Finnish sovereignty. The municipality has a population of () and covers an area of of which is water. The population density is . The municipality is unilingually Swedish an ...

. There is no deep harbor; the island can only be reached with boats. There are small, barely surfacing rocks northwest of Märket, called Märketshällor ("stones of Märket"), which are too small to sustain vegetation. The island consists of mostly smooth

diabase Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-gra ...

rock, with a maximum natural elevation of . Most of the area is regularly washed over with seawater in storms, and scoured by

drift ice Drift or Drifts may refer to: Geography * Drift or ford (crossing) of a river * Drift (navigation), difference between heading and course of a vessel * Drift, Kentucky, unincorporated community in the United States * In Cornwall, England: ** D ...

in winter. Plant life, which is limited to low-growing grasses and herbs, persists only in some protected spots. Twenty-three plant species have been identified altogether. The

halophilic A halophile (from the Greek word for 'salt-loving') is an extremophile that thrives in high salt concentrations. In chemical terms, halophile refers to a Lewis acidic species that has some ability to extract halides from other chemical species. ...

grass '' Puccinellia capillaris'' and the herbaceous ''

Sagina nodosa ''Sagina nodosa'', the knotted pearlwort, is a species in the genus '' Sagina'', native to northern Europe. It is a low-growing plant up to 15 cm tall, with paired leaves up to 1 cm long. The flower Flowers, also known as bloom ...

'' (knotted pearlwort) are found scattered throughout the island. Among rarer species, '' Spergularia marina'' (salt sandspurry) grows on Märket. ''

Salix caprea ''Salix caprea'', known as goat willow, pussy willow or great sallow, is a common species of willow native to Europe and western and central Asia.Meikle, R. D. (1984). ''Willows and Poplars of Great Britain and Ireland''. BSBI Handbook 4. . De ...

'' (goat willow) grows on an abandoned building. There are large

grey seal The grey seal (''Halichoerus grypus'') is a large seal of the family Phocidae, which are commonly referred to as "true seals" or "earless seals". The only species classified in the genus ''Halichoerus'', it is found on both shores of the Nort ...

communities around Märket, and the island has been a target for seal safaris.

International border and lighthouse

There is a

on the Finnish side of the current border, which has been unmanned and automated since 1979. When it was built by the

in 1885, the island was considered a no-man's land, so the lighthouse was simply built upon the highest point of the island. However, the location selected was within the Swedish portion of the island. Though the lighthouse was formally on the Swedish side of the border, it was never considered Swedish, nor administered from Sweden. As a result, the border was adjusted in 1985 so that the lighthouse is now located on Finnish territory. The adjustment was carried out such that no net transfer of territory occurred, and the ownership of the coastline was unchanged so as not to interfere with each country's fishing rights. This resulted in an unusual shape for the international border to satisfy both Finnish and Swedish interests. The adjusted border takes the form of an inverted 'S', and the lighthouse is connected to the rest of Finland only by a short stretch of land. The border on the island is around long. The border is regularly resurveyed every 25 years by officials representing both countries. The last such joint inspection took place in August 2006. The border is marked by holes drilled into the rock, because the seasonal drift ice would shear off any protruding markers. Because of the

Nordic Passport Union The Nordic Passport Union allows citizens of the Nordic countries—Iceland, Denmark, Norway, Sweden, and Finland—to travel and reside in another Nordic country without any travel documentation (e.g. a passport or national identity card) or ...

and the

Schengen Agreement The Schengen Agreement ( , ) is a treaty which led to the creation of Europe's Schengen Area, in which internal border checks have largely been abolished. It was signed on 14 June 1985, near the town of Schengen, Luxembourg, by five of the t ...

, there have been no passport checks or other border formalities at the border since 1958, so intra-Nordic/intra-Schengen visitors may visit the island freely. The lighthouse has been automated since 1979 and the surrounding buildings are no longer used. The increasing general availability of

GPS The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide geol ...

has made the lighthouse's primary function redundant.

Radio amateurs activity

Radio amateurs An amateur radio operator is someone who uses equipment at an amateur radio station to engage in two-way personal communications with other amateur operators on radio frequencies assigned to the amateur radio service. Amateur radio operators ...

around the world consider the Finnish part of Märket (Märket Reef or Market Reef as they call it) a separate entity, distinct from Finland, the Åland Islands and Sweden. The Finnish part of Märket Reef used to be one of the world's most desired "countries" to contact among radio amateurs because of its special status and relative remoteness. One or more amateur radio expeditions to the island occur most years, weather permitting. During these expeditions, tens of thousands of radio contacts are made with people in several parts of the world. At high seas, landing is only possible with a helicopter. Pictures of Märket are shown on QSL cards. The official prefix for use on the Finnish side is OJ0

call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally as ...

prefix A prefix is an affix which is placed before the stem of a word. Particularly in the study of languages, a prefix is also called a preformative, because it alters the form of the word to which it is affixed. Prefixes, like other affixes, can b ...

for Märket Reef. An OJ0 vanity callsign can be obtained, for a fee, from Traficom.fi, the Finnish Transport and Communication Agency. Amateurs with licenses in countries supporting CEPT can operate from the reef while using the OJ0/ prefix in front of one's own call sign. All radio activity on the island is by visitors on

DX-pedition A DX-pedition is an expedition to what is considered an exotic place by amateur radio operators and DX listeners, typically because of its remoteness, access restrictions, or simply because there are very few radio amateurs active from that pl ...

s. When the Finnish part of the reef was given its special status in amateur radio, in the late 1960s the lighthouse keeper himself became a licensed amateur radio operator, who initially used the call OH0MA. On the Swedish side of Märket Reef, the call signs 8S9M and SI8MI have been used.

Climate

Märket has a continental climate affected by oceanic influences; it has a reputation for being one of the windiest places in Finland.Association finlandaise des phares
– Presentation of the Island A meteorological station has been managed by the lighthouse keepers since 1896, and an automatic station of the

Finnish Meteorological Institute The Finnish Meteorological Institute (FMI; ; ) is the government agency responsible for gathering and reporting weather data and forecasts in Finland. It is a part of the Ministry of Transport and Communications but it operates semi-autonomousl ...

was inaugurated on 10 November 1977, shortly before its automation. The effect of the sea is very important to the climate of the island; thermal inertia dramatically reduces the temperature fluctuations during the year compared to those of the continent, and to a lesser extent, those of the central part of

Fasta Åland Fasta Åland ( or , meaning mainland Åland) is the largest and most populous island of Åland, an autonomous province of Finland. The island is home to the provincial capital Mariehamn. About ninety percent of the archipelago's population lives ...

, the largest island of the archipelago of

. Märket holds five records for daytime temperatures among Finnish weather stations, all in the period between 29 November and 1 January, with on 15 December 2006, and on 31 December 1975. The average yearly temperature is roughly and is one of the highest in Finland, with the month of January being milder than on the continent ( on average), and a warm summer ( on average in July). The island is drier than the mainland; the average annual rainfall does not usually surpass .Institut météorologique national de Finlande
– Statistiques climatiques de la période 1971–2000

References

External links

2021 OJ0D Satellite Radio DXpedition to Märket
* https://sral.info/2018/06/19/market-calling/
2007 Radio DXpedition to Märket

Configurable map centred on Märket
from Citizen's Mapsite of Finland
Market Reef at MostTraveledPeople.comJoint border survey between Finland and Sweden in progress
from

Helsingin Sanomat , abbreviated ''HS'' and colloquially known as , is the largest subscription newspaper in Finland and the Nordic countries, owned by Sanoma. Except after certain holidays, it is published daily. Its name derives from that of the Finnish capital ...