A gat (Dutch : zeegat, gat; German : Seegatt, Seegat or diminutive Gatje) is an inshore channel or strait connecting coastal waters with the open sea or dividing two landmasses, such as two islands or an island and a peninsula. [1] [2] Gats are usually relatively narrow but deep and are in many instances constantly eroded by currents flowing back and forth, such as tidal currents. The term is mostly used for features on the North Sea and Baltic Sea coasts.
According to Whittow a gat is either a strait dividing offshore islands from the mainland e.g. the Frisian Islands, or it is an opening in a line of sea cliffs allowing access to the coast from inland. [1] The term sometimes also refers to a shallower passage on lagoon coasts, including those without any tidal range, and can also refer to shallow bars in an area of mudflats.
It is similar, but not identical, to a gut, which is a narrow river channel or strait prior to joining an open ocean or estuary. Leser restricts its use to deep, but relatively narrow inlets in the Wadden Sea that are scoured out by currents, giving the example of the gap between the Frisian islands of Juist and Nordeney. [3]
In Dutch the term can be interpreted quite broadly, as it can refer to an entrance to the open sea formed by the mouth of an inlet, an inland sea or even a river; and also to an opening between coastal islands or coasts in general. [2]
The term "gat" is primarily (though not exclusively) applied to waterways of the North Sea and Baltic Sea coasts of Europe. A similar term of related but not identical meaning, gut, is mainly applied to channels of the coastal waters of the Atlantic coast of North America.
Passages between inner and outer coastal waters, such as at the ends of spits of lagoons or along bodden coasts are also referred to as gats. [4]
The comparatively large quantities of water that flow quite quickly through a gat cause heavy erosion that results in a channel deeper than the rest of the surrounding seabed and also endangers neighbouring islands. When the water masses from mud flats behind the islands surge out again into the sea as ebb currents, they flow rapidly again through the narrow gat. But as these water masses break out into the open sea, they spread out and slow down. As a result, on this seaward side of the gat, the particles of sand and mud carried with the water settle and form an ebb delta with its shallower waters between the islands. The sandbanks so formed are often known in Germany as plate (pronounced "plah-ter", see Kachelotplate). The point where the water pouring out of the gat runs over these banks, which often lie in an arc between the islands, is the sand bar (German : Barre). This is the shallowest part of the gat for shipping, but also the deepest point on the shallowest line between the islands. A flood delta is formed in a similar way on the landward side of the gat.
A navigation channel to the open sea is usually marked out in the gats by the waterway and shipping authorities. The area of the bar is usually the most dangerous spot; this is where rip tides and, especially when the current flows against the wind, very dangerous ground swells may occur.
The name comes from the Low German and Dutch word "gat" which means "gap". "Gat" is incorporated into some Dutch or Dutch-derived proper names of passages (e. g. Kattegat, Veerse Gat) which may or may not be proper gats. [5] In English names, both "gat" (e. g. Fisherman's Gat) and "gut" (e. g. Digby Gut, Hull Gut, Gut of Canso) are seen.
In German, "Gat" (as well as "Seegatt" and the diminutive "Gatje") can refer to an arm of the sea which is not necessarily subject to strong tidal currents; for instance, the Prerower Strom ("Prerow Stream"), which is a regressive delta, is a gat. [6] Seegatt (also "Neues [Pillauer] Tief" [New {Pillau} Deep]) is the German proper name of the Strait of Baltiysk (Pillau) which connects the Vistula Lagoon to the Baltic Sea. [7]
The name of Hell Gate, a gat (or gut) in the East River of New York City, is derived from archaic Dutch Hellegat (meaning possibly "clear opening"), [8] a fairly common toponym (place name) for waterways in the Low Countries. [9]
The following is a list of gats, including named gats that may or may not be true gats as defined above:
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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 Kattegat is a 30,000 km2 (12,000 sq mi) sea area bounded by the Jutlandic peninsula in the west, the Danish straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden in the east. The Baltic Sea drains into the Kattegat through the Danish straits. The sea area is a continuation of the Skagerrak and may be seen as a bay of the North Sea and North Atlantic Ocean, but in traditional Scandinavian usage, this is not the case.
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into coastal lagoons and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around many parts of the world.
Firth is a word in the English and Scots languages used to denote various coastal waters in the United Kingdom, predominantly within Scotland. In the Northern Isles, it more often refers to a smaller inlet. It is linguistically cognate to Scandinavian fjord and fjard, with the original meaning of "sailable waterway". The word has a more constrained sense in English. Bodies of water named "firths" tend to be more common on the Scottish east coast, or in the southwest of the country, although the Firth of Clyde is an exception to this. The Highland coast contains numerous estuaries, straits, and inlets of a similar kind, but not called "firth" ; instead, these are often called sea lochs. Before about 1850, the spelling "Frith" was more common.
The Skagerrak is a strait running between the Jutland peninsula of Denmark, the east coast of Norway and the west coast of Sweden, connecting the North Sea and the Kattegat sea.
Barrier islands are a coastal landform, a type of dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend for hundreds of kilometers, with islands periodically separated by tidal inlets. The largest barrier island in the world is Padre Island of Texas, United States, at 113 miles (182 km) long. Sometimes an important inlet may close permanently, transforming an island into a peninsula, thus creating a barrier peninsula, often including a beach, barrier beach. Though many are long and narrow, the length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls. The amount of vegetation on the barrier has a large impact on the height and evolution of the island.
In geography, a sound is a smaller body of water usually connected to a sea or an ocean. A sound may be an inlet that is deeper than a bight and wider than a fjord; or a narrow sea channel or an ocean channel between two land masses, such as a strait; or also a lagoon between a barrier island and the mainland.
The Strait of Baltiysk is a strait enabling passage from the Baltic Sea into the brackish Vistula Lagoon, located in Kaliningrad Oblast, Russia. The constructed strait separates the Vistula Spit from the peninsula which was part of the Vistula Spit in the 15th century and now is part of Sambian Peninsula.
Zingst is the easternmost portion of the three-part Fischland-Darß-Zingst Peninsula, located in Mecklenburg-Vorpommern, Germany, between the cities of Rostock and Stralsund on the southern shore of the Baltic Sea.
The Thames Estuary is where the River Thames meets the waters of the North Sea, in the south-east of Great Britain.
Seymour Inlet is one of the lesser travelled of the principal inlets of the British Columbia Coast. Unlike larger inlets such as Knight or Bute, it is not flanked by mountains but by relatively low, but still rugged, coastal hill-country and forms a maze of complex, narrow waterways and tidal pools and lagoons. It is located within a corresponding maze of peninsulas on the mainland on the northwest side of the Queen Charlotte Strait region.
The Danish straits are the straits connecting the Baltic Sea to the North Sea through the Kattegat and Skagerrak. Historically, the Danish straits were internal waterways of Denmark; however, following territorial losses, Øresund and Fehmarn Belt are now shared with Sweden and Germany, while the Great Belt and the Little Belt have remained Danish territorial waters. The Copenhagen Convention of 1857 made all the Danish straits open to commercial shipping. The straits have generally been regarded as an international waterway.
Bodden are briny bodies of water often forming lagoons, along the southwestern shores of the Baltic Sea, primarily in Germany's state of Mecklenburg-Vorpommern. These lagoons can be found especially around the island of Rügen, Usedom and the Fischland-Darss-Zingst peninsula. Some of them are protected reserves, forming the Western Pomerania Lagoon Area National Park.
The Rhine–Meuse–Scheldt delta is a river delta in the Netherlands formed by the confluence of the Rhine, the Meuse and the Scheldt rivers. In some cases, the Scheldt delta is considered a separate delta to the Rhine–Meuse delta. The result is a multitude of islands, branches and branch names, in which a waterway that appears to be one continuous stream may have numerous separate names for different sections, e.g. Rhine → Bijlands Kanaal → Pannerdens Kanaal → Nederrijn → Lek → Nieuwe Maas → Het Scheur → Nieuwe Waterweg. Since the Rhine contributes most of the water, the term "Rhine Delta" is commonly used, although this name is also used for the delta where the Alpine Rhine flows into Lake Constance. By some calculations, the Rhine–Meuse–Scheldt delta covers 25,347 km2 (9,787 sq mi), making it the largest in Europe.
A regressive delta is a body of sediment that forms at the landward end of a gut.
A gut is a narrow coastal body of water, a channel or strait, usually one that is subject to strong tidal currents flowing back and forth.
Estuaries of Australia are features of the Australian coastline. They are linked to tides, river mouths and coastal features and conditions. In many cases the features of estuaries are also named inlets.
A hapua is a river-mouth lagoon on a mixed sand and gravel (MSG) beach, formed at the river-coast interface where a typically braided, although sometimes meandering, river interacts with a coastal environment that is significantly affected by longshore drift. The lagoons which form on the MSG coastlines are common on the east coast of the South Island of New Zealand and have long been referred to as hapua by Māori people. This classification differentiates hapua from similar lagoons located on the New Zealand coast termed waituna.
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: CS1 maint: location missing publisher (link) Retrieved at "Seegatt". Pierer's Universal Lexicon. Zeno.org. Retrieved April 10, 2014.(in German)