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Operation Catherine

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107-693: Operation Catherine was a proposed Baltic Sea offensive by the United Kingdom 's Royal Navy to be undertaken in early 1940. It aimed at interdicting German seaborne commerce with the Soviet Union , Sweden , Finland , Estonia and Latvia . In particular, an objective was to stop the flow of Swedish iron ore to Germany . The driving force behind the project was the First Lord of the Admiralty Winston Churchill , and

214-547: A caisson of water in which boats float while being moved between two levels; and inclined planes where a caisson is hauled up a steep railway. To cross a stream, road or valley (where the delay caused by a flight of locks at either side would be unacceptable) the valley can be spanned by a navigable aqueduct – a famous example in Wales is the Pontcysyllte Aqueduct (now a UNESCO World Heritage Site ) across

321-510: A drainage divide atop a ridge , generally requiring an external water source above the highest elevation . The best-known example of such a canal is the Panama Canal . Many canals have been built at elevations, above valleys and other waterways. Canals with sources of water at a higher level can deliver water to a destination such as a city where water is needed. The Roman Empire 's aqueducts were such water supply canals. The term

428-415: A "cistern", or depressed area just downstream from the fall, to "cushion" the water by providing a deep pool for its kinetic energy to be diffused in. Vertical falls work for drops of up to 1.5 m in height, and for discharge of up to 15 cubic meters per second. The transport capacity of pack animals and carts is limited. A mule can carry an eighth-ton [250 pounds (113 kg)] maximum load over

535-635: A Russian group of scientists found over five thousand airplane wrecks, sunken warships, and other material, mainly from World War II, on the bottom of the sea. Since the end of World War II , various nations, including the Soviet Union , the United Kingdom and the United States have disposed of chemical weapons in the Baltic Sea, raising concerns of environmental contamination. Today, fishermen occasionally find some of these materials:

642-496: A canal has a series of dams and locks that create reservoirs of low speed current flow. These reservoirs are referred to as slack water levels , often just called levels . A canal can be called a navigation canal when it parallels a natural river and shares part of the latter's discharges and drainage basin , and leverages its resources by building dams and locks to increase and lengthen its stretches of slack water levels while staying in its valley . A canal can cut across

749-413: A combination of the three, depending on available water and available path: Smaller transportation canals can carry barges or narrowboats , while ship canals allow seagoing ships to travel to an inland port (e.g., Manchester Ship Canal ), or from one sea or ocean to another (e.g., Caledonian Canal , Panama Canal ). At their simplest, canals consist of a trench filled with water. Depending on

856-575: A head-on argument and apparently co-operated while he pointed out problems. Finally, on 20 January 1940, Churchill cancelled the operation. Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark , Estonia , Finland , Germany , Latvia , Lithuania , Poland , Russia , Sweden , 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. It

963-549: A journey measured in days and weeks, though much more for shorter distances and periods with appropriate rest. Besides, carts need roads. Transport over water is much more efficient and cost-effective for large cargoes. The oldest known canals were irrigation canals, built in Mesopotamia c.  4000 BC , in what is now Iraq . The Indus Valley civilization of ancient India ( c.  3000 BC ) had sophisticated irrigation and storage systems developed, including

1070-577: A limit to Øresund and Darss Sill (depth of 18 m (59 ft)), and a limit to the Belt Sea. The shallow sills are obstacles to the flow of heavy salt water from the Kattegat into the basins around Bornholm and Gotland . The Kattegat and the southwestern Baltic Sea are well oxygenated and have a rich biology. The remainder of the Sea is brackish, poor in oxygen, and in species. Thus, statistically,

1177-581: A rather low gradient for its time. The canal is still in use after renovation. In the Middle Ages , water transport was several times cheaper and faster than transport overland. Overland transport by animal drawn conveyances was used around settled areas, but unimproved roads required pack animal trains, usually of mules to carry any degree of mass, and while a mule could carry an eighth ton, it also needed teamsters to tend it and one man could only tend perhaps five mules, meaning overland bulk transport

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1284-657: A substantial part of the Baltic Sea. After 1945, the German population was expelled from all areas east of the Oder-Neisse line , making room for new Polish and Russian settlement. Poland gained most of the southern shore . The Soviet Union gained another access to the Baltic with the Kaliningrad Oblast , that had been part of German-settled East Prussia . The Baltic states on the eastern shore were annexed by

1391-629: A trade empire all around the Baltic. Later, the Norse fought for control of the Baltic against Wendish tribes dwelling on the southern shore. The Norse also used the rivers of Russia for trade routes, finding their way eventually to the Black Sea and southern Russia. This Norse-dominated period is referred to as the Viking Age . Since the Viking Age , the Scandinavians have referred to

1498-459: A uniform altitude. Other, generally later, canals took more direct routes requiring the use of various methods to deal with the change in level. Canals have various features to tackle the problem of water supply. In cases, like the Suez Canal, the canal is open to the sea. Where the canal is not at sea level, a number of approaches have been adopted. Taking water from existing rivers or springs

1605-815: Is a shelf sea and marginal sea of the Atlantic with limited water exchange between the two, making it an inland sea . The Baltic Sea drains through the Danish straits into the Kattegat by way of the Øresund , Great Belt and Little Belt . It includes the Gulf of Bothnia (divided into the Bothnian Bay and the Bothnian Sea ), the Gulf of Finland , the Gulf of Riga and the Bay of Gdańsk . The " Baltic Proper "

1712-422: Is a channel that cuts across a drainage divide , making a navigable channel connecting two different drainage basins . Both navigations and canals use engineered structures to improve navigation: Since they cut across drainage divides, canals are more difficult to construct and often need additional improvements, like viaducts and aqueducts to bridge waters over streams and roads, and ways to keep water in

1819-421: Is about 349,644 km (134,998 sq mi) and the volume is about 20,000 km (4,800 cu mi). The periphery amounts to about 8,000 km (5,000 mi) of coastline. The Baltic Sea is one of the largest brackish inland seas by area, and occupies a basin (a Zungenbecken ) formed by glacial erosion during the last few ice ages . The International Hydrographic Organization defines

1926-413: Is adapted to reproducing also with no ice in the sea. The sea ice also harbors several species of algae that live in the bottom and inside unfrozen brine pockets in the ice. Due to the often fluctuating winter temperatures between above and below freezing, the saltwater ice of the Baltic Sea can be treacherous and hazardous to walk on, in particular in comparison to the more stable fresh water-ice sheets in

2033-752: Is bordered on its northern edge, at latitude 60°N, by Åland 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–Baltic Canal and to the German Bight of the North Sea via

2140-460: Is likely to be a misspelling. In addition to fish the sea also provides amber , especially from its southern shores within today's borders of Poland , Russia and Lithuania . First mentions of amber deposits on the South Coast of the Baltic Sea date back to the 12th century. The bordering countries have also traditionally exported lumber, wood tar , flax , hemp and furs by ship across

2247-421: Is part of the entrance, but the Bay of Mecklenburg and the Bay of Kiel are parts of the Baltic Sea. Another usual border is the line between Falsterbo , Sweden, and Stevns Klint , Denmark, as this is the southern border of Øresund. It is also the border between the shallow southern Øresund (with a typical depth of 5–10 meters only) and notably deeper water. Drogden Sill (depth of 7 m (23 ft)) sets

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2354-701: Is presumed, introduced in Italy by Bertola da Novate in the 16th century. This allowed wider gates and also removed the height restriction of guillotine locks . To break out of the limitations caused by river valleys, the first summit level canals were developed with the Grand Canal of China in 581–617 AD whilst in Europe the first, also using single locks, was the Stecknitz Canal in Germany in 1398. In

2461-599: Is rarely less than 30 metres (98 ft) wide. In the 5th century BC, Achaemenid king Xerxes I of Persia ordered the construction of the Xerxes Canal through the base of Mount Athos peninsula, Chalkidiki , northern Greece. It was constructed as part of his preparations for the Second Persian invasion of Greece , a part of the Greco-Persian Wars . It is one of the few monuments left by

2568-418: Is steeper than the desired canal gradient. They are constructed so the falling water's kinetic energy is dissipated in order to prevent it from scouring the bed and sides of the canal. A canal fall is constructed by cut and fill . It may be combined with a regulator, bridge, or other structure to save costs. There are various types of canal falls, based on their shape. One type is the ogee fall, where

2675-412: Is that, while derived from the aforementioned root, the name of the sea is related to names for various forms of water and related substances in several European languages, that might have been originally associated with colors found in swamps (compare Proto-Slavic *bolto "swamp"). Yet another explanation is that the name originally meant "enclosed sea, bay" as opposed to open sea. In the Middle Ages

2782-452: Is the pound lock , which consists of a chamber within which the water level can be raised or lowered connecting either two pieces of canal at a different level or the canal with a river or the sea. When there is a hill to be climbed, flights of many locks in short succession may be used. Prior to the development of the pound lock in 984 AD in China by Chhaio Wei-Yo and later in Europe in

2889-654: The Archipelago Sea southwest of Finland. The remainder of the Baltic does not freeze during a normal winter, except sheltered bays and shallow lagoons such as the Curonian Lagoon . The ice reaches its maximum extent in February or March; typical ice thickness in the northernmost areas in the Bothnian Bay , the northern basin of the Gulf of Bothnia, is about 70 cm (28 in) for landfast sea ice. The thickness decreases farther south. Freezing begins in

2996-603: The Dutch dominated the Baltic trade in the seventeenth century. In the eighteenth century, Russia and Prussia became the leading powers over the sea. Sweden's defeat in the Great Northern War brought Russia to the eastern coast. Russia became and remained a dominating power in the Baltic. Russia's Peter the Great saw the strategic importance of the Baltic and decided to found his new capital, Saint Petersburg , at

3103-658: The Elbe , Oder and Weser being linked by canals. In post-Roman Britain, the first early modern period canal built appears to have been the Exeter Canal , which was surveyed in 1563, and open in 1566. The oldest canal in the European settlements of North America, technically a mill race built for industrial purposes, is Mother Brook between the Boston, Massachusetts neighbourhoods of Dedham and Hyde Park connecting

3210-615: The Great Belt , the Little Belt and The Sound ( Öresund / Øresund ), connect the Baltic Sea with the Kattegat and Skagerrak strait in the North Sea . The water temperature of the Baltic Sea varies significantly depending on exact location, season and depth. At the Bornholm Basin, which is located directly east of the island of the same name, the surface temperature typically falls to 0–5 °C (32–41 °F) during

3317-827: The Kiel Canal . The Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area includes the Baltic Sea and the Kattegat , without calling Kattegat a part of the Baltic Sea, "For the purposes of this Convention the 'Baltic Sea Area' shall be the Baltic Sea and the Entrance to the Baltic Sea, bounded by the parallel of the Skaw in the Skagerrak at 57°44.43'N." Historically,

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3424-486: The Kingdom of Denmark collected Sound Dues from ships at the border between the ocean and the land-locked Baltic Sea, in tandem: in the Øresund at Kronborg castle near Helsingør ; in the Great Belt at Nyborg ; and in the Little Belt at its narrowest part then Fredericia , after that stronghold was built. The narrowest part of Little Belt is the "Middelfart Sund" near Middelfart . Geographers widely agree that

3531-725: 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

3638-543: The Naviglio Grande built between 1127 and 1257 to connect Milan with the river Ticino . The Naviglio Grande is the most important of the lombard " navigli " and the oldest functioning canal in Europe. Later, canals were built in the Netherlands and Flanders to drain the polders and assist transportation of goods and people. Canal building was revived in this age because of commercial expansion from

3745-540: The North Atlantic Ocean , the Baltic Sea is enclosed by Sweden and Denmark to the west, Finland to the northeast, and the Baltic countries to the southeast. It is about 1,600 km (990 mi) long, an average of 193 km (120 mi) wide, and an average of 55 metres (180 ft) deep. The maximum depth is 459 m (1,506 ft) which is on the Swedish side of the center. The surface area

3852-545: The Phoenix metropolitan area was the most complex in ancient North America. A portion of the ancient canals has been renovated for the Salt River Project and now helps to supply the city's water. The Sinhalese constructed the 87 km (54 mi) Yodha Ela in 459 A.D. as a part of their extensive irrigation network which functioned in a way of a moving reservoir due to its single banking aspect to manage

3959-528: The River Brue at Northover with Glastonbury Abbey , a distance of about 1.75 kilometres (1,900 yd). Its initial purpose is believed to be the transport of building stone for the abbey, but later it was used for delivering produce, including grain, wine and fish, from the abbey's outlying properties. It remained in use until at least the 14th century, but possibly as late as the mid-16th century. More lasting and of more economic impact were canals like

4066-614: The Songhai Empire of West Africa, several canals were constructed under Sunni Ali and Askia Muhammad I between Kabara and Timbuktu in the 15th century. These were used primarily for irrigation and transport. Sunni Ali also attempted to construct a canal from the Niger River to Walata to facilitate conquest of the city but his progress was halted when he went to war with the Mossi Kingdoms . Around 1500–1800

4173-585: The Victual Brothers held Gotland . Starting in the 11th century, the southern and eastern shores of the Baltic were settled by migrants mainly from Germany , a movement called the Ostsiedlung ("east settling"). Other settlers were from the Netherlands , Denmark , and Scotland . The Polabian Slavs were gradually assimilated by the Germans. Denmark gradually gained control over most of

4280-556: The reservoirs built at Girnar in 3000 BC. This is the first time that such planned civil project had taken place in the ancient world. In Egypt , canals date back at least to the time of Pepi I Meryre (reigned 2332–2283 BC), who ordered a canal built to bypass the cataract on the Nile near Aswan . In ancient China , large canals for river transport were established as far back as the Spring and Autumn period (8th–5th centuries BC),

4387-516: The shipworm . Storm surge floods are generally taken to occur when the water level is more than one metre above normal. In Warnemünde about 110 floods occurred from 1950 to 2000, an average of just over two per year. Historic flood events were the All Saints' Flood of 1304 and other floods in the years 1320, 1449, 1625, 1694, 1784 and 1825. Little is known of their extent. From 1872, there exist regular and reliable records of water levels in

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4494-404: The stratum the canal passes through, it may be necessary to line the cut with some form of watertight material such as clay or concrete. When this is done with clay, it is known as puddling . Canals need to be level, and while small irregularities in the lie of the land can be dealt with through cuttings and embankments, for larger deviations other approaches have been adopted. The most common

4601-479: The Åland War . They bombarded Sveaborg , which guards Helsinki ; and Kronstadt , which guards Saint Petersburg; and they destroyed Bomarsund in Åland . After the unification of Germany in 1871, the whole southern coast became German. World War I was partly fought in the Baltic Sea. After 1920 Poland was granted access to the Baltic Sea at the expense of Germany by the Polish Corridor and enlarged

4708-471: The 12th century. River navigations were improved progressively by the use of single, or flash locks . Taking boats through these used large amounts of water leading to conflicts with watermill owners and to correct this, the pound or chamber lock first appeared, in the 10th century in China and in Europe in 1373 in Vreeswijk , Netherlands. Another important development was the mitre gate , which was, it

4815-472: The 15th century, either flash locks consisting of a single gate were used or ramps, sometimes equipped with rollers, were used to change the level. Flash locks were only practical where there was plenty of water available. Locks use a lot of water, so builders have adopted other approaches for situations where little water is available. These include boat lifts , such as the Falkirk Wheel , which use

4922-559: The Baltic Sea almost entirely surrounded by the alliance's members, leading some commentators to label the sea a ″NATO lake″. Such an arrangement has also existed for the European Union (EU) since May 2004 following the accession of the Baltic states and Poland. The remaining non-NATO and non-EU shore areas are Russian: the Saint Petersburg area and the Kaliningrad Oblast exclave . Winter storms begin arriving in

5029-656: The Baltic Sea as Austmarr ("Eastern Sea"). "Eastern Sea", appears in the Heimskringla and Eystra salt appears in Sörla þáttr . 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 ,

5136-407: The Baltic Sea"). Eventually, it was Sweden that virtually encompassed the Baltic Sea . In Sweden, the sea was then referred to as Mare Nostrum Balticum ("Our Baltic Sea"). The goal of Swedish warfare during the 17th century was to make the Baltic Sea an all-Swedish sea ( Ett Svenskt innanhav ), something that was accomplished except the part between Riga in Latvia and Stettin in Pomerania. However,

5243-573: The Baltic Sea. The highest was the flood of 1872 when the water was an average of 2.43 m (8 ft 0 in) above sea level at Warnemünde and a maximum of 2.83 m (9 ft 3 in) above sea level in Warnemünde. In the last very heavy floods the average water levels reached 1.88 m (6 ft 2 in) above sea level in 1904, 1.89 m (6 ft 2 in) in 1913, 1.73 m (5 ft 8 in) in January 1954, 1.68 m (5 ft 6 in) on 2–4 November 1995 and 1.65 m (5 ft 5 in) on 21 February 2002. An arm of

5350-440: The Baltic coast, until she lost much of her possessions after being defeated in the 1227 Battle of Bornhöved . In the 13th to 16th centuries, the strongest economic force in Northern Europe was the Hanseatic League , a federation of merchant cities around the Baltic Sea and the North Sea . In the sixteenth and early seventeenth centuries, Poland , Denmark , and Sweden fought wars for Dominium maris baltici ("Lordship over

5457-464: The Baltic. Sweden had from early medieval times exported iron and silver mined there, while Poland had and still has extensive salt mines. Thus, the Baltic Sea has long been crossed by much merchant shipping. The lands on the Baltic's eastern shore were among the last in Europe to be converted to Christianity . This finally happened during the Northern Crusades : Finland in the twelfth century by Swedes, and what are now Estonia and Latvia in

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5564-401: The Bothnian Bay and the Bothnian Sea were frozen with solid ice near the Baltic coast and dense floating ice far from it. In 2008, almost no ice formed except for a short period in March. During winter, fast ice , which is attached to the shoreline, develops first, rendering ports unusable without the services of icebreakers . Level ice , ice sludge , pancake ice , and rafter ice form in

5671-463: The Elder . Pliny mentions an island named Baltia (or Balcia ) with reference to accounts of Pytheas and Xenophon . It is possible that Pliny refers to an island named Basilia ("the royal") in On the Ocean by Pytheas. Baltia also might be derived from "belt", and therein mean "near belt of sea, strait". Others have suggested that the name of the island originates from the Proto-Indo-European root *bʰel meaning "white, fair", which may echo

5778-546: The Gulf of Bothnia normally thaw in late April, with some ice ridges persisting until May in the eastern extremities of the Gulf of Finland. In the northernmost reaches of the Bothnian Bay, ice usually stays until late May; by early June it is practically always gone. However, in the famine year of 1867 remnants of ice were observed as late as 17 July near Uddskär . Even as far south as Øresund , remnants of ice have been observed in May on several occasions; near Taarbaek on 15 May 1942 and near Copenhagen on 11 May 1771. Drift ice

5885-405: The Gulf of Riga. This description meant that the whole of the Baltic Sea was covered with ice. Since 1720, the Baltic Sea has frozen over entirely 20 times, most recently in early 1987, which was the most severe winter in Scandinavia since 1720. The ice then covered 400,000 km (150,000 sq mi). During the winter of 2010–11, which was quite severe compared to those of the last decades,

5992-453: The Mare Suebicum, named for the Suebi tribe, during the spring months, as a brackish sea where the ice broke apart and chunks floated about. The Suebi eventually migrated southwest to temporarily reside in the Rhineland area of modern Germany, where their name survives in the historic region known as Swabia . Jordanes called it the Germanic Sea in his work, the Getica . In the early Middle Ages , Norse (Scandinavian) merchants built

6099-406: The Persian Empire in Europe . Greek engineers were also among the first to use canal locks , by which they regulated the water flow in the Ancient Suez Canal as early as the 3rd century BC. There was little experience moving bulk loads by carts, while a pack-horse would [i.e. 'could'] carry only an eighth of a ton. On a soft road a horse might be able to draw 5/8ths of a ton. But if

6206-476: The Southwest by 1300 CE. Archaeologists working at a major archaeological dig in the 1990s in the Tucson Basin, along the Santa Cruz River, identified a culture and people that may have been the ancestors of the Hohokam. This prehistoric group occupied southern Arizona as early as 2000 BCE, and in the Early Agricultural period grew corn, lived year-round in sedentary villages, and developed sophisticated irrigation canals. The large-scale Hohokam irrigation network in

6313-448: The Soviet Union. The Baltic then separated opposing military blocs: NATO and the Warsaw Pact . Neutral Sweden developed incident weapons to defend its territorial waters after the Swedish submarine incidents . This border status restricted trade and travel. It ended only after the collapse of the Communist regimes in Central and Eastern Europe in the late 1980s. Finland and Sweden joined NATO in 2023 and 2024, respectively, making

6420-436: The canal pressure with the influx of water. It was also designed as an elongated reservoir passing through traps creating 66 mini catchments as it flows from Kala Wewa to Thissa Wawa . The canal was not designed for the quick conveying of water from Kala Wewa to Thissa Wawa but to create a mass of water between the two reservoirs, which would in turn provided for agriculture and the use of humans and animals. They also achieved

6527-418: The canal to form a dam. They are generally placed in pre-existing grooves in the canal bank. On more modern canals, "guard locks" or gates were sometimes placed to allow a section of the canal to be quickly closed off, either for maintenance, or to prevent a major loss of water due to a canal breach. A canal fall , or canal drop, is a vertical drop in the canal bed. These are built when the natural ground slope

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6634-462: The canal. Where large amounts of goods are loaded or unloaded such as at the end of a canal, a canal basin may be built. This would normally be a section of water wider than the general canal. In some cases, the canal basins contain wharfs and cranes to assist with movement of goods. When a section of the canal needs to be sealed off so it can be drained for maintenance stop planks are frequently used. These consist of planks of wood placed across

6741-409: The channel. There are two broad types of canal: Historically, canals were of immense importance to commerce and the development, growth and vitality of a civilization. In 1855 the Lehigh Canal carried over 1.2 million tons of anthracite coal; by the 1930s the company which built and operated it for over a century ceased operation. The few canals still in operation in our modern age are a fraction of

6848-402: The climates transition from moderate continental to subarctic on the northernmost coastlines. On the long-term average, the Baltic Sea is ice-covered at the annual maximum for about 45% of its surface area. The ice-covered area during such a typical winter includes the Gulf of Bothnia , the Gulf of Finland , the Gulf of Riga , the archipelago west of Estonia, the Stockholm archipelago , and

6955-399: The drop follows an s-shaped curve to create a smooth transition and reduce turbulence . However, this smooth transition does not dissipate the water's kinetic energy, which leads to heavy scouring. As a result, the canal needs to be reinforced with concrete or masonry to protect it from eroding. Another type of canal fall is the vertical fall, which is "simple and economical". These feature

7062-436: The early thirteenth century by Danes and Germans ( Livonian Brothers of the Sword ). The Teutonic Order gained control over parts of the southern and eastern shore of the Baltic Sea, where they set up their monastic state . Lithuania was the last European state to convert to Christianity . In the period between the 8th and 14th centuries, there was much piracy in the Baltic from the coasts of Pomerania and Prussia , and

7169-446: The elevation for those guns would be 30 degrees. In the new state, her top speed would have been about 13–14 kn (24–26 km/h; 15–16 mph) in action. As well as cutting off German iron ore supplies, Churchill anticipated that the show of force would encourage the Scandinavian nations to join the war against Nazi Germany . The First Sea Lord Admiral Sir Dudley Pound opposed the plan for several reasons. The armour plating

7276-440: The first summit level canal to use pound locks in Europe was the Briare Canal connecting the Loire and Seine (1642), followed by the more ambitious Canal du Midi (1683) connecting the Atlantic to the Mediterranean. This included a staircase of 8 locks at Béziers , a 157 metres (515 ft) tunnel, and three major aqueducts. Canal building progressed steadily in Germany in the 17th and 18th centuries with three great rivers,

7383-402: The freedom to make deliveries well away from rail lined road beds or ditches in the dirt which could not operate in the winter. The longest extant canal today, the Grand Canal in northern China, still remains in heavy use, especially the portion south of the Yellow River . It stretches from Beijing to Hangzhou at 1,794 kilometres (1,115 miles). Canals are built in one of three ways, or

7490-500: The geographical location of the sea (in Germanic languages), or its size in relation to smaller gulfs (in Old Latvian), or tribes associated with it (in Old Russian the sea was known as the Varanghian Sea). In modern languages, it is known by the equivalents of "East Sea", "West Sea", or "Baltic Sea" in different languages: 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

7597-428: The head of planning was Admiral of the Fleet Lord Cork . Events overtook the proposed operation and resulted in its cancellation. Churchill proposed a substantial naval squadron: three Revenge -class battleships , an aircraft carrier, five cruisers, two destroyer flotillas , submarines and supporting auxiliaries. The battleships would need to be significantly modified to resist air and submarine attack to pass through

7704-486: The ice further into the north, and much of the waters north of Gotland were again free of ice, which had then packed against the shores of southern Finland. The effects of the afore-mentioned high-pressure area did not reach the southern parts of the Baltic Sea, and thus the entire sea did not freeze over. However, floating ice was additionally observed near Świnoujście harbor in January 2010. In recent years before 2011,

7811-443: The interior lakes. The Baltic Sea flows out through the Danish straits ; however, the flow is complex. A surface layer of brackish water discharges 940 km (230 cu mi) per year into the North Sea . Due to the difference in salinity , by salinity permeation principle, a sub-surface layer of more saline water moving in the opposite direction brings in 475 km (114 cu mi) per year. It mixes very slowly with

7918-516: The limits of the Baltic Sea as follows: 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 Saint Petersburg . The Gulf of Riga lies between

8025-549: The load were carried by a barge on a waterway, then up to 30 tons could be drawn by the same horse. — technology historian Ronald W. Clark referring to transport realities before the industrial revolution and the Canal age . Hohokam was a society in the North American Southwest in what is now part of Arizona , United States, and Sonora , Mexico. Their irrigation systems supported the largest population in

8132-480: The longest canal in the world today and the oldest extant one. It is 1,794 kilometres (1,115 mi) long and was built to carry the Emperor Yang Guang between Zhuodu ( Beijing ) and Yuhang ( Hangzhou ). The project began in 605 and was completed in 609, although much of the work combined older canals, the oldest section of the canal existing since at least 486 BC. Even in its narrowest urban sections it

8239-534: The longest one of that period being the Hong Gou (Canal of the Wild Geese), which according to the ancient historian Sima Qian connected the old states of Song, Zhang, Chen, Cai, Cao, and Wei. The Caoyun System of canals was essential for imperial taxation, which was largely assessed in kind and involved enormous shipments of rice and other grains. By far the longest canal was the Grand Canal of China , still

8346-546: The maximum ice cover was 315,000 km (122,000 sq mi), which was reached on 25 February 2011. The ice then extended from the north down to the northern tip of Gotland , with small ice-free areas on either side, and the east coast of the Baltic Sea was covered by an ice sheet about 25 to 100 km (16 to 62 mi) wide all the way to Gdańsk . This was brought about by a stagnant high-pressure area that lingered over central and northern Scandinavia from around 10 to 24 February. After this, strong southern winds pushed

8453-712: The more of the entrance that is included in its definition, the healthier the Baltic appears; conversely, the more narrowly it is defined, the more endangered its biology appears. Tacitus called it the Suebic Sea, Latin: Mare Suebicum after the Germanic people of the Suebi , and Ptolemy Sarmatian Ocean after the Sarmatians , but the first to name it the Baltic Sea ( Medieval Latin : Mare Balticum )

8560-463: 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 (49 ft). Offshore of the landfast ice, the ice remains very dynamic all year, and it is relatively easily moved around by winds and therefore forms pack ice , made up of large piles and ridges pushed against the landfast ice and shores. In spring, the Gulf of Finland and

8667-565: The most recent available report from the Helsinki Commission notes that four small scale catches of chemical munitions representing approximately 105 kg (231 lb) of material were reported in 2005. This is a reduction from the 25 incidents representing 1,110 kg (2,450 lb) of material in 2003. Until now, the U.S. Government refuses to disclose the exact coordinates of the wreck sites. Deteriorating bottles leak mustard gas and other substances, thus slowly poisoning

8774-632: 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 in the Baltic; the case is also known as

8881-459: The naming of seas after colours relating to the cardinal points (as per Black Sea and Red Sea ). This '*bʰel' root and basic meaning were retained in Lithuanian (as baltas ), Latvian (as balts ) and Slavic (as bely ). On this basis, a related hypothesis holds that the name originated from this Indo-European root via a Baltic language such as Lithuanian. Another explanation

8988-474: The northern extremities of the Gulf of Bothnia typically in the middle of November, reaching the open waters of the Bothnian Bay in early January. The Bothnian Sea , the basin south of Kvarken , freezes on average in late February. The Gulf of Finland and the Gulf of Riga freeze typically in late January. In 2011, the Gulf of Finland was completely frozen on 15 February. The ice extent depends on whether

9095-506: The numbers that once fueled and enabled economic growth, indeed were practically a prerequisite to further urbanization and industrialization. For the movement of bulk raw materials such as coal and ores are difficult and marginally affordable without water transport. Such raw materials fueled the industrial developments and new metallurgy resulting of the spiral of increasing mechanization during 17th–20th century, leading to new research disciplines, new industries and economies of scale, raising

9202-477: The peak of the winter and rises to 15–20 °C (59–68 °F) during the peak of the summer, with an annual average of around 9–10 °C (48–50 °F). A similar pattern can be seen in the Gotland Basin , which is located between the island of Gotland and Latvia. In the deep of these basins the temperature variations are smaller. At the bottom of the Bornholm Basin, deeper than 80 m (260 ft),

9309-772: The port of Gdynia in rivalry with the port of the Free City of Danzig . After the Nazis' rise to power, Germany reclaimed the Memelland and after the outbreak of the Eastern Front (World War II) occupied the Baltic states. In 1945, the Baltic Sea became a mass grave for retreating soldiers and refugees on torpedoed troop transports . The sinking of the Wilhelm Gustloff remains the worst maritime disaster in history, killing (very roughly) 9,000 people. In 2005,

9416-604: The pre-railroad days of the industrial revolution, water transport was the gold standard of fast transportation. The first artificial canal in Western Europe was the Fossa Carolina built at the end of the 8th century under personal supervision of Charlemagne . In Britain, the Glastonbury Canal   is believed to be the first post-Roman canal and was built in the middle of the 10th century to link

9523-583: The preferred physical border between the Baltic and North Seas is the Langelandsbælt (the southern part of the Great Belt strait near Langeland ) and the Drogden -Sill strait. The Drogden Sill is situated north of Køge Bugt and connects Dragør in the south of Copenhagen to Malmö ; it is used by the Øresund Bridge , including the Drogden Tunnel . By this definition, the Danish straits

9630-520: The region during October. These have caused numerous shipwrecks , and contributed to the extreme difficulties of rescuing passengers of the ferry M/S Estonia en route from Tallinn , Estonia, to Stockholm , Sweden, in September 1994, which claimed the lives of 852 people. Older, wood-based shipwrecks such as the Vasa tend to remain well-preserved, as the Baltic's cold and brackish water does not suit

9737-418: The sea was known by a variety of names. The name Baltic Sea became dominant after 1600. Usage of Baltic and similar terms to denote the region east of the sea started only in the 19th century. The Baltic Sea was known in ancient Latin language sources as Mare Suebicum or even Mare Germanicum . Older native names in languages that used to be spoken on the shores of the sea or near it usually indicate

9844-439: The shallow waters. HMS  Royal Sovereign would have been fitted with very large bulges to her hull to make her 140 ft (43 m) wide to increase her buoyancy and thus reduce her draught by 9 ft (2.7 m) even after the addition of 4 to 5 in (100 to 130 mm) of deck armour (some 2,000 long tons (2,000 t) of armour would be used in total). Only two of her main turrets would be retained, but elsewhere,

9951-589: The source of the Germanic word, Latin balteus "belt". Adam of Bremen himself compared the sea with a belt, stating that it is so named because it stretches through the land as a belt ( Balticus, eo quod in modum baltei longo tractu per Scithicas regiones tendatur usque in Greciam ). He might also have been influenced by the name of a legendary island mentioned in the Natural History of Pliny

10058-650: The south, the Bay of Gdańsk lies east of the Hel Peninsula on the Polish coast and west of the Sambia Peninsula in Kaliningrad Oblast . The Bay of Pomerania lies north of the islands of Usedom/Uznam 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 ,

10165-480: The standard of living for any industrialized society. Most ship canals today primarily service bulk cargo and large ship transportation industries, whereas the once critical smaller inland waterways conceived and engineered as boat and barge canals have largely been supplanted and filled in, abandoned and left to deteriorate, or kept in service and staffed by state employees, where dams and locks are maintained for flood control or pleasure boating. Their replacement

10272-484: The temperature typically is 1–10 °C (34–50 °F), and at the bottom of the Gotland Basin, at depths greater than 225 m (738 ft), the temperature typically is 4–7 °C (39–45 °F). Generally, offshore locations, lower latitudes and islands maintain maritime climates , but adjacent to the water continental climates are common, especially on the Gulf of Finland . In the northern tributaries

10379-643: The upper waters, resulting in a salinity gradient from top to bottom, with most of the saltwater remaining below 40 to 70 m (130 to 230 ft) deep. The general circulation is anti-clockwise: northwards along its eastern boundary, and south along with the western one . Canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation ) or for conveyancing water transport vehicles (e.g. water taxi ). They carry free, calm surface flow under atmospheric pressure , and can be thought of as artificial rivers . In most cases,

10486-573: The valley of the River Dee . Another option for dealing with hills is to tunnel through them. An example of this approach is the Harecastle Tunnel on the Trent and Mersey Canal . Tunnels are only practical for smaller canals. Some canals attempted to keep changes in level down to a minimum. These canals known as contour canals would take longer, winding routes, along which the land was

10593-437: The winter is mild, moderate, or severe. In severe winters ice can form around southern Sweden and even in the Danish straits . According to the 18th-century natural historian William Derham , during the severe winters of 1703 and 1708, the ice cover reached as far as the Danish straits. Frequently, parts of the Gulf of Bothnia and the Gulf of Finland are frozen, in addition to coastal fringes in more southerly locations such as

10700-466: Was also expensive, as men expect compensation in the form of wages, room and board. This was because long-haul roads were unpaved, more often than not too narrow for carts, much less wagons, and in poor condition, wending their way through forests, marshy or muddy quagmires as often as unimproved but dry footing. In that era, as today, greater cargoes, especially bulk goods and raw materials , could be transported by ship far more economically than by land; in

10807-414: Was also observed on 11 May 1799. The ice cover is the main habitat for two large mammals, the grey seal ( Halichoerus grypus ) and the Baltic ringed seal ( Pusa hispida botnica ), both of which feed underneath the ice and breed on its surface. Of these two seals, only the Baltic ringed seal suffers when there is not adequate ice in the Baltic Sea, as it feeds its young only while on ice. The grey seal

10914-458: Was an option in some cases, sometimes supplemented by other methods to deal with seasonal variations in flow. Where such sources were unavailable, reservoirs  – either separate from the canal or built into its course – and back pumping were used to provide the required water. In other cases, water pumped from mines was used to feed the canal. In certain cases, extensive "feeder canals" were built to bring water from sources located far from

11021-407: Was gradual, beginning first in the United States in the mid-1850s where canal shipping was first augmented by, then began being replaced by using much faster , less geographically constrained & limited, and generally cheaper to maintain railways . By the early 1880s, canals which had little ability to economically compete with rail transport, were off the map. In the next couple of decades, coal

11128-399: Was in short supply and was needed elsewhere; the three battleships were badly needed, particularly if Italy and Japan also declared war; the impact of air power was underestimated in the plan; and the loss of such a squadron would encourage Italy and Japan to declare war. Despite those cogent arguments and widespread opposition, Churchill continued to push hard for Catherine. Pound avoided

11235-424: Was increasingly diminished as the heating fuel of choice by oil, and growth of coal shipments leveled off. Later, after World War I when motor-trucks came into their own, the last small U.S. barge canals saw a steady decline in cargo ton-miles alongside many railways, the flexibility and steep slope climbing capability of lorries taking over cargo hauling increasingly as road networks were improved, and which also had

11342-426: Was once used to describe linear features seen on the surface of Mars , Martian canals , an optical illusion. A navigation is a series of channels that run roughly parallel to the valley and stream bed of an unimproved river. A navigation always shares the drainage basin of the river. A vessel uses the calm parts of the river itself as well as improvements, traversing the same changes in height. A true canal

11449-459: Was the eleventh-century German chronicler Adam of Bremen . The origin of the latter name is speculative and it was adopted into Slavic and Finnic languages spoken around the sea, very likely due to the role of Medieval Latin in cartography . It might be connected to the Germanic word belt , a name used for two of the Danish straits, the Belts , while others claim it to be directly derived from

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