The 'Baltic Sea' is located in
Northern Europe, from 53°N to 66°N
latitude and from 20°E to 26°E
longitude. It is bounded by the
Scandinavian Peninsula, the mainland of
Europe, and the
Danish islands. It drains into the
Kattegat by way of the
Øresund, the
Great Belt and the
Little Belt. The Kattegat continues through the
Skagerrak into the
North Sea and the
Atlantic Ocean. The Baltic Sea is artificially linked to the
White Sea by the
White Sea Canal and to the North Sea by the
Kiel Canal.
Etymology
Map of the Baltic Sea
The first to name it the ''Baltic Sea'' ("''Mare Balticum''") was eleventh century German chronicler
Adam of Bremen. The origin of the name is speculative. He may have based it on the mythical North European island
Baltia, mentioned by
Xenophon. Another possibility is that Adam of Bremen connected to the Germanic word ''belt'', a name used for some of the Danish straits, while others claim it to be derived from
Latin ''balteus'' (belt).
[1]. Still another proposed derivation from the
Indo-European root
★ ''bhel'' meaning ''white, shining'' (note that 'baltas' means 'white' in today
Lithuanian, while 'balts' means the same in modern
Latvian language). The latter name could have influenced the
Baltica myth because Baltic tribes lived on the shores of the Baltic Sea in ancient times and had contacts with the
Mediterranean civilizations, being a well-known source of
amber for ancient
Greece and later for the
Roman Empire. However, it is indisputable that the source of the name for the
Baltic countries is the name of the Baltic Sea, not the other way around.
Name in other languages
The Baltic Sea is known by the equivalents of "East Sea", "West Sea", or "Baltic Sea" in different languages:
★ In ''
Germanic languages'', except English, '''East Sea''' is used:
Danish (''Østersøen''),
Dutch (''Oostzee''),
German (''Ostsee''),
Norwegian (''Østersjøen''), and
Swedish (''Östersjön''); in addition,
Finnish, a ''
Balto-Finnic language'' has
calqued the Swedish term as ''Itämeri'', disregarding the geography; the sea is west of Finland.
★ In another ''
Balto-Finnic language'',
Estonian, it is called the '''West Sea''' (''Läänemeri'').
★ '''Baltic Sea''' is used in ''
English''; in ''
Latin'' (''Mare Balticum'') and the ''
Romance languages''
French (''Mer Baltique''),
Italian (''Mar Baltico''),
Portuguese (''Mar Báltico'') and
Spanish (''Mar Báltico''); in the ''
Slavic languages''
Polish (''Morze Bałtyckie'' or ''Bałtyk''),
Bulgarian (''Baltijsko More'' (''Балтийско море'')),
Kashubian (''Bôłt''), and
Russian (''Baltiyskoye Morye'' (''Балтийское море'')); and in the ''
Baltic languages''
Latvian (''Baltijas jūra'') and
Lithuanian (''Baltijos jūra'').
Geophysical data
Baltic Sea in winter
The Baltic Sea is a
brackish inland sea, alleged to be the largest body of brackish water in the world (Other possibilities include Black Sea). It occupies a basin formed by glacial erosion.
Dimensions
The Baltic sea is about 1600
km (1000
mi) long, an average of 193 km (120 mi) wide, and an average of 55
m (180
ft, 30
fathoms) deep. The maximum depth is 459 m (1506 ft), on the Swedish side of the center. The surface area is about 377,000
km² (145,522
sq mi) and the volume is about 21,000
cubic km (5040
cubic miles). The periphery amounts to about 8000= km (4968 mi) of coastline.
[1]
These figures are somewhat variable because a number of different estimates have been made.
Sea ice
As a long-term average the Baltic Sea is ice covered for about 45% of its surface area at maximum annually. The ice-covered area during such a normal winter includes the
Gulf of Bothnia, the
Gulf of Finland,
Gulf of Riga and Vainameri in the Estonian archipelago. The Baltic Proper does not freeze during a normal winter, with the exception of sheltered bays and shallow lagoons such as the
Courland Lagoon. The ice reaches its maximum extent in February or March; typical ice thickness in the northernmost areas in the
Bothnian Bay is about 70
cm for landfast sea ice. The thickness decreases when moving south.
Freezing begins in the northern coast of Gulf of Bothnia typically in early November, reaching the open waters of
Bay of Bothnia, the northern basin of the Gulf of Bothnia, in early January. The
Bothnian Sea, the basin south of it, freezes on average in late February. The Gulf of Finland and the Gulf of Riga freeze typically in late January.
The ice extent depends on whether the winter is mild, moderate or severe. Severe winters can ice the regions around
Denmark and southern
Sweden, and on rare cases the whole sea is frozen, such as in 1942. In 1987, some 96% of the Baltic Sea was iced, leaving only a small patch of open water to the west of
Bornholm in the Baltic proper. Contrary to this, in milder winters the Bay of Bothnia and Gulf of Finland are the only larger areas that are ice covered, in addition to coastal fringes in more southerly locations such as the Gulf of Riga.
In spring, the Gulf of Finland and the Bothnian Sea normally thaw during late April, with some ice ridges persisting until May in the eastern Gulf of Finland. In the Bay of Bothnia ice usually stays until late May; by early June it is practically always gone.
During winter,
fast ice which is attached to the
shoreline, develops first, rendering the ports unusable without the services of
icebreakers.
Level ice,
ice sludge,
pancake ice or
rafter ice form in the more open regions. The gleaming expanse of ice is similar to the
Arctic, with wind-driven pack ice and ridges up to 15 m, and was noted by the ancients. Offshore of the landfast ice the ice remains very dynamic all year, because of its thickness it is relatively easily moved around by winds and therefore makes up large ridges and pile up against the landfast ice and shores.
The ice cover is the main habitat only for a few larger species. The largest of them are the seals that both feed and breed on the ice, although the sea ice also harbors several species of algae that live in the bottom and inside brine pockets in the ice.
Hydrography
The Baltic Sea flows out through the
Danish straits; however, the flow is complex. A surface layer of brackish water discharges 940 cubic km per year into the
North Sea. Due to the difference in
salinity, a sub-surface layer of more saline water moving in the opposite direction brings in 475 cubic km per year. It mixes very slowly with the upper waters, resulting in a salinity gradient from top to bottom, with most of the salt water remaining below 40 to 70 m deep. The general circulation is counter-clockwise: northwards along its eastern boundary, and south along the western one (Alhonen 88).
The difference between the outflow and the inflow comes entirely from fresh water. More than 250 streams drain a basin of about 1.6 million km², contributing a volume of 660 cubic km per year to the Baltic. They include the major rivers of north Europe, such as the
Oder, the
Vistula, the
Neman, the
Daugava and the
Neva. Some of this water is polluted. Additional fresh water comes from the difference of
precipitation less evaporation, which is positive.
An important source of salty water are infrequent inflows of
North Sea water into the Baltic. Such inflows, important to the Baltic ecosystem because of the oxygen they transport into the Baltic deeps, used to happen on average every four to five years until the 1980s. In recent decades they have become less frequent. The latest three occurred in 1983, 1993 and 2003 suggesting a new inter-inflow period of about ten years.
The water level is generally far more dependent on the regional wind situation than on tidal effects. However, tidal currents occur in narrow passages in the western parts of the Baltic Sea.
The
significant wave height is generally much lower than that of the
North Sea. Violent and sudden storms often sweep the surface, due to large transient temperature differences and a long reach of wind. Seasonal winds also cause small changes in sea level, of the order of 0.5 m (Alhonen 88).
Salinity
The Baltic Sea's
salinity is much lower than that of ocean water (which averages 3.5%, or 35 parts per thousand), as a result of abundant freshwater runoff from the surrounding land; indeed, runoff contributes roughly one-fortieth its total volume per year, as the volume of the basin is about 21 000 cubic kilometres and yearly runoff is about 500 cubic kilometres. The open surface waters of the central basin have salinity of 6 to 8 ppt. At the semienclosed bays with major freshwater inflows, such as head of Finnish Gulf with Neva mouth and head of Bothnian gulf with close mouths of Lule, Tornio and Kemi, the salinity is considerably lower. Below 40 to 70 m, the salinity is between 10 and 15 ppt in the open Baltic Sea, and more than this near Danish Straits.
The flow of fresh water into the sea from rivers and the flow of salty from the South builds up a gradient of salinity in the Baltic Sea. Near the
Danish straits the salinity is close to that of the Kattegat, but still not fully oceanic, because the saltiest water that passes the straits is still already mixed with considerable amounts of outflow water.. The salinity steadily decreases towards North and East. At the northern part of the
Gulf of Bothnia the water no longer tastes salty and many fresh water species live in the sea. The salinity gradient is paralleled by a temperature gradient. These two factors limit many species of animals and plants to a relatively narrow region of Baltic Sea.
The most saline water remains on the bottom, creating a barrier to the exchange of
oxygen and nutrients, fostering totally different maritime environments.
Regional emergence
The land is still emerging
isostatically from its subsident state, which was caused by the weight of the last glaciation. Consequently, the surface area and the depth of the sea are diminishing. The uplift is about eight millimetres per year on the Finnish coast of the northernmost Gulf of Bothnia.
Geographic data
Subdivisions
The northern part of the Baltic Sea is known as the
Gulf of Bothnia, of which the northernmost part is the
Bay of Bothnia or
Bothnian Bay. The more rounded southern basin of the gulf is called
Bothnian Sea and immediately to the south of it lies the
Sea of Åland. The
Gulf of Finland connects the Baltic Sea with
St Petersburg. The
Gulf of Riga lies between the
Latvian capital city of
Riga and the
Estonian island of
Saaremaa.
The
Northern Baltic Sea lies between the
Stockholm area, southwestern Finland and Estonia. The
Western and Eastern Gotland Basins form the major parts of the Central Baltic Sea or Baltic proper. The
Bornholm Basin is the area east of
Bornholm, and the shallower
Arkona Basin extends from Bornholm to the Danish isles of
Falster and
Zealand.
In the south, the
Bay of Gdańsk lies east of the
Hel peninsula on the Polish coast and west of
Sambia in
Kaliningrad Oblast. The
Bay of Pomerania lies north of the islands of
Usedom and
Wolin, east of
Rügen. Between Falster and the German coast lie the
Bay of Mecklenburg and
Bay of Lübeck. The westernmost part of the Baltic Sea is the
Bay of Kiel. The three
Danish straits, the
Great Belt, the
Little Belt and
The Sound (''Øresund''), connect the Baltic Sea with the
Kattegat bay and
Skagerrak strait in the
North Sea. The confluence of these two seas at
Skagen on the northern tip of
Denmark is a visual spectacle visited by many tourists each year.
Land use
The Baltic sea drainage basin is roughly four times the surface area of the sea itself. About 48% of the region is forested, with Sweden and Finland containing the majority of the forest, especially around the Gulfs of Bothnia and Finland.
About 20% of the land is used for agriculture and pasture, mainly in Poland and around the edge of the Baltic Proper, in Germany, Denmark and Sweden. About 17% of the basin is unused open land with another 8% of wetlands. Most of the latter are in the Gulfs of Bothnia and Finland.
The rest of the land is heavily populated.
Demographics
About 85 million people live in the Baltic drainage basin, 15 million within 10 km of the coast and 29 million within 50 km of the coast. Around 22 million live in population centers of over 250,000. 90% of these are concentrated in the 10 km band around the coast. Of the nations containing all or part of the basin, Poland includes 45% of the 85 million, Russia 12%, Sweden 10% and the others (see below) less than 6% each.
Geologic history
The Baltic Sea somewhat resembles a
riverbed, with two tributaries, the
Gulf of Finland and
Gulf of Bothnia.
Geological surveys show that before the
Pleistocene instead of the Baltic Sea was a wide plain around a big river called the
Eridanos. Several
glaciation episodes during the
Pleistocene scooped out the river bed into the sea basin. By the time of the last, or
Eemian interglacial (
MIS 5e), the Eemian sea was in place.
From that time the waters underwent a geologic history summarized under the names listed below. Many of the stages are named after marine animals (e.g. the
Littorina mollusk) that are clear markers of changing water temperatures and salinity.
A cliff ''Olando kepurė'',
Lithuania — a shore of the former Littorina Sea
The factors that determined the sea’s characteristics were the submergence or emergence of the region due to the weight of ice and subsequent isostatic readjustment, and the connecting channels it found to the
North Sea-
Atlantic, either through the straits of
Denmark or at what are now the large lakes of
Sweden, and the
White Sea-
Arctic Sea.
★
Eemian Sea, 130,000-115,000 BP
★
Baltic ice lake, 12,600-10,300 BP
★
Yoldia Sea, 10,300-9500 BP
★
Ancylus Lake, 9500-8000 BP
★
Mastogloia Sea 8000 BP-7500 BP
★
Littorina Sea, 7500-4000 BP
★
Post-littorina Sea 4000 BP-current
History
At the time of the
Roman Empire, the Baltic Sea was known as the ''Mare Suebicum'' or ''Mare Sarmaticum''.
Tacitus in his AD
98 ''Agricola'' and ''Germania'' described the Mare Suebicum, named for the
Suebi tribe, during the spring months, as a
brackish sea when the ice on the Baltic Sea broke apart and chunks floated about. The Suebi eventually migrated south west to reside for a while in the Rhineland area of modern Germany, where their name survives in the historic region known as
Swabia. The
Sarmatian tribes inhabited Eastern Europe and southern Russia.
Jordanes called it the ''Germanic Sea'' in his work the
Getica.
Since the
Viking age, the Scandinavians have called it "the Eastern Lake" (''Austmarr'', "Eastern Sea", appears in the
Heimskringla and ''Eystra salt'' appears in
Sörla þáttr), but
Saxo Grammaticus recorded in
Gesta Danorum an older name ''
Gandvik'', ''"-vik"'' being
Old Norse for "bay", which implies that the Vikings correctly regarded it as an inlet of the sea. (Another form of the name, "Grandvik", attested in at least one English translation of Gesta Danorum, is likely to be a misspelling.)
In addition to
fish the sea also provides
amber, especially from its southern shores. The bordering countries have traditionally provided
lumber,
wood tar,
flax,
hemp, and
furs. Sweden had from early medieval times also a flourishing
mining industry, especially on
iron ore and
silver.
Poland had and still has extensive
salt mines. All this has provided for rich trading since the Roman times.
In the early Middle Ages,
Vikings of Scandinavia fought for control over the sea with
Slavic Pomeranians. The Vikings used the rivers of Russia for trade routes, finding their way eventually to the
Black Sea and southern Russia.
Lands next to the sea's eastern shore were among the last in Europe to be converted into
Christianity in the
Northern Crusades:
Finland in the twelfth century by the Swedes, and what are now
Estonia and
Latvia in the early thirteenth century by the Danes and the Germans (
Livonian Brothers of the Sword). The powerful German
Teutonic Knights gained control over most of the southern and eastern shore of the Baltic Sea, while fighting the
Poles, the
Danes, the
Swedes, the
Russians of ancient
Novgorod, and the
Lithuanians (the
last Europeans to convert to Christianity).
Later, the strongest economic force in Northern Europe became the
Hanseatic league, which used the Baltic Sea to establish trade routes between its member cities. In the sixteenth and early seventeenth centuries,
Polish-Lithuanian Commonwealth,
Denmark and
Sweden fought wars for ''Dominium Maris Baltici'' ("Ruling over the Baltic Sea"). Eventually, it was the
Swedish Empire that virtually encompassed the Baltic Sea. In Sweden the sea was then referred to as ''Mare Nostrum Balticum'' ("Our Baltic Sea").
In the eighteenth century,
Russia and
Prussia became the leading powers over the sea. Russia's
Peter the Great saw the strategic importance of the Baltic and decided to found his new capital,
St. Petersburg at the mouth of the
Neva river at the east end of the
Gulf of Finland. There was much trading not just within the Baltic region but also with the North Sea region, especially eastern
England and the
Netherlands: their fleets needed the Baltic timber, tar, flax and hemp.
During the
Crimean War, a joint
British and
French fleet attacked the Russian fortresses by bombarding
Sveaborg, which guards
Helsinki;
Kronstadt, which guards St. Petersburg; and by destroying
Bomarsund in the
Åland Islands. After the unification of
Germany in
1871, the whole southern coast became German. The
First World War was partly fought in the Baltic Sea. After
1920,
Poland returned to the Baltic Sea, and the Polish ports of
Gdynia and
Gdańsk became leading ports of the Baltic.
During
the Second World War, Germany reclaimed all of the southern shore and much of the eastern by occupying Poland and the
Baltic states. In
1945, the Baltic Sea became a mass grave for drowned people on torpedoed
refugee ships.
As of 2004, the sinking of the
Wilhelm Gustloff remains the worst
maritime disaster, killing (very roughly) 9,000 people. In 2005, a Russian group of scientists found over five thousand airplane wrecks, sunken warships, and other
materiel mainly from
the Second World War, lying at the bottom of the sea.
After
1945, the sea was a border between opposing military blocks: in the case of military conflict in Germany, in parallel with a Soviet offensive towards the
Atlantic Ocean, communist Poland's fleet was prepared to invade the Danish isles.
Since May
2004, on the accession of the
Baltic states and
Poland, the Baltic Sea has been almost entirely surrounded by countries of the
European Union (EU). The only remaining non-EU areas are the Russian
metropolis of St. Petersburg and the
Kaliningrad Oblast exclave.
Winter storms begin arriving in the region during October. These have caused numerous shipwrecks, such as the sinking of the ferry ''
M/S Estonia'' en route from
Tallinn, Estonia, to
Stockholm, Sweden, in
1994, which claimed the lives of hundreds. Older, wood-based shipwrecks such as the ''
Vasa'' tend to remain well-preserved, as the Baltic's cold and brackish water does not suit the
shipworm.
Biology
Approximately 100,000 km² of the Baltic's seafloor (a quarter of its total area) is a variable dead zone. The more saline (and therefore denser) water remains on the bottom, isolating it from surface waters and the atmosphere. This leads to decreased oxygen concentrations within the zone. It is mainly bacteria that grow in it, digesting organic material and releasing hydrogen sulfide. Because of this large anaerobic zone, the seafloor ecology differs from that of the neighbouring Atlantic.
The low salinity of the Baltic sea has led to the evolution of many slightly divergent species, such as the Baltic Sea
herring, which is a smaller variant of the
Atlantic herring. The
benthic fauna consists mainly of ''
Monoporeia affinis'', which is originally a freshwater species. The lack of
tides has affected the marine species as compared with the Atlantic.
Economy
Construction of the
Great Belt Bridge (
1997) and
Oresund Bridge (
1999) over the
international waterway of the
Danish Straits has limited the Baltic Sea to medium-sized vessels. The Baltic Sea is the main trade route for export of Russian oil. Many of the neighboring countries are concerned about this, since a major oil leak would be disastrous in the Baltic given the slow exchange of water and the many unique species. The tourism industries, especially in economies dependent on tourism like northeastern Germany, are naturally very concerned.
Shipbuilding is practiced in many large shipyards around the Baltic:
Gdańsk,
Szczecin in Poland,
HDW in
Kiel, Germany,
Karlskrona and
Kockums in
Malmö, Sweden, and
Rauma,
Turku,
Helsinki in Finland,
Rīga,
Liepāja in Latvia and
Klaipėda in Lithuania.
There are several cargo and passenger
ferry operators on the Baltic Sea, such as
Silja Line,
Polferries,
Viking Line,
Tallink and
Superfast Ferries.
The Helsinki Convention
1974 Convention
For the first time ever, all the sources of pollution around an entire sea were made subject to a single convention, signed in 1974 by the then seven Baltic coastal states. The 1974 Convention entered into force on 3 May 1980.
1992 Convention
In the light of political changes and developments in international environmental and maritime law, a new convention was signed in 1992 by all the states bordering on the Baltic Sea, and the European Community. After ratification the Convention entered into force on 17 January 2000. The Convention covers the whole of the Baltic Sea area, including inland waters and the water of the sea itself, as well as the sea-bed. Measures are also taken in the whole catchment area of the Baltic Sea to reduce land-based pollution. The Convention on the Protection of the Marine Environment of the Baltic Sea Area, 1992, entered into force on 17 January 2000.
The governing body of the Convention is the Helsinki Commission
[2], also known as HELCOM, or Baltic Marine Environment Protection Commission. The present contracting parties are Denmark, Estonia, the European Community, Finland, Germany, Latvia, Lithuania, Poland, Russia and Sweden.
The ratification instruments where deposited by the European Community, Germany, Latvia and Sweden in 1994, by Estonia and Finland in 1995, by Denmark in 1996, by Lithuania in 1997 and by Poland and Russia in November 1999.
Countries
Main articles: Baltic Sea countries
Islands and archipelagoes
Main articles: List of islands in the Baltic Sea
★
Åland Islands (
Ahvenanmaa) (
Finland,
autonomous)
★
Archipelago Sea (
Finland)
★
★
Parainen (
Pargas)
★
★
Nauvo (
Nagu)
★
★
Korppoo (
Korpo)
★
★
Houtskari (
Houtskär)
★
★
Kustavi
★
Bornholm (
Denmark)
★
Gotland (
Sweden)
★
Hailuoto (
Finland)
★
Hiiumaa (
Estonia)
★
Kotlin (
Russia)
★
Muhu (
Estonia)
★
Öland (
Sweden)
★
Rügen (
Germany)
★
Saaremaa (
Estonia)
★
Stockholm archipelago (
Sweden)
★
★
Värmdön (
Sweden)
★
Usedom or Uznam (split between
Germany and
Poland)
★
Valassaaret (
Finland)
★
Wolin (
Poland)
Cities
See also
★
Baltic
★
Baltic region
★
Baltic states
★
Council of the Baltic Sea States
★
List of rivers of the Baltic Sea
★
Nord Stream
★
Northern Europe
★
Ports of the Baltic Sea
★
Scandinavia
References
1. Project Runeberg.
★ Fairbridge, Rhodes. ''The Encyclopedia of Oceanography''. Pentti Alhonen, "Baltic Sea", pp. 87-91. New York: Van Nostrand Reinhold Company, 1966.
External links
★
Protect the Baltic Sea while it's still not too late.
★
The Baltic Sea Portal - a site maintained by the
Finnish Institute of Marine Research (FIMR) (in English, Finnish, Swedish and Estonian)
★
Encyclopedia of Baltic History
★
1493 H. Schedel Map with Mare Germanicum
★
Old shipwrecks in the Baltic
★
How the Baltic Sea was changing - Prehistory of the Baltic from the
Polish Geological Institute
★
Late Weichselian and Holocene shore displacement history of the Baltic Sea in Finland - more prehistory of the Baltic from the
Department of Geography of the
University of Helsinki
★
Baltic Environmental Atlas: Interactive map of the Baltic Sea region
★
Baltic Sea Photos
★
OstholsteinInformation about the culture and landscape of Ostholstein (German)
★
List of all ferry lines in the Baltic Sea
★
The Helsinki Commission (HELCOM) HELCOM is the governing body of the "Convention on the Protection of the Marine Environment of the Baltic Sea Area"
★
Baltice.org is a single access point to reliable and up to date information related to winter navigation in the Baltic Sea area
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