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For other uses, see Shoal (disambiguation).
Sandbar between St. Agnes, Isles of Scilly and Gugh in Cornwall
Sandbar between St. Agnes, Isles of Scilly and Gugh in Cornwall
A tidal sandbar connecting the islands of Waya and Wayasewa of the Yasawa Islands, Fiji
A tidal sandbar connecting the islands of Waya and Wayasewa of the Yasawa Islands, Fiji

A shoal is a somewhat linear landform within or extending into a body of water, typically composed of sand, silt or small pebbles. St Agnes (Aganas is the southernmost populated Island of the Isles of Scilly, England, United Kingdom. Gugh (pronounced to rhyme with 'hugh' Cornish: Keow meaning hedge banks is a Tidal island in the Isles of Scilly, United Kingdom Cornwall ( Kernow ˈkɛɹnɔʊ is the most southwesterly county of England, on the Peninsula that lies to the west of the River Tamar The Yasawa Group is an Archipelago of about 20 volcanic Islands in the Western Division of Fiji, with an approximate total area of The word linear comes from the Latin word linearis, which means created by lines. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles Silt is Soil or rock derived Granular material of a Grain size between sand and clay A pebble is a clast of rock with a Particle size of 4 to 64 Millimeters based on the Krumbein phi scale of Sedimentology Alternatively termed sandbar or sandbank, a bar is characteristically long and narrow (linear) and develops where a stream or ocean current promote deposition of granular material, resulting in localized shallowing (shoaling) of the water. A stream is a body of Water with a current, confined within a bed and stream-banks An ocean current is continuous directed movement of Ocean water. Deposition is the geological process by which material is added to a Landform or land mass A granular material is a conglomeration of discrete Solid, macroscopic particles characterized by a loss of energy whenever the particles interact (the most common example would Bars can appear in the sea, in a lake, or in a river. This article is about the body of water For other uses see SEA and Seas. A lake (from Latin lacus) is a Terrain feature (or Physical feature) a body of Liquid on the surface of a world that is localized to the "Riverine" redirects here For the use of that term in Maritime geography, see there Alternatively a bar may separate a lake from the sea, as in the case of an ayre. An ayre is a body of water positioned very near to the ocean and divided from the sea by a narrow bar of land They are typically composed of sand, although could be of any granular matter that the moving water has access to and is capable of shifting around (for example, soil, silt, gravel, cobble, shingle, or even boulders). Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel Silt is Soil or rock derived Granular material of a Grain size between sand and clay Gravel is rock that is of a specific Particle size range In Geology, gravel is any loose rock that is larger than two millimeters (2mm A shingle beach is a Beach which is armoured with Pebbles or small to medium sized cobbles In Geology, a boulder is a rock with grain size of usually no less than 256 mm (10 Inches diameter The grain size of the material comprising a bar is related to the size of the waves or the strength of the currents moving the material, but the availability of material to be worked by waves and currents is also important.

The term bar can apply to landform features spanning a considerable range in size, from a length of a few meters in a small stream to marine depositions stretching for hundreds of kilometres along a coastline, often called barrier islands. The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand The coast is defined as the part of the land adjoining or near the Ocean.

In a nautical sense, a bar is a shoal, similar to a reef: a shallow formation of (usually) sand that is a navigation or grounding hazard. Seamanship is the art of operating a ship or boat It involves a knowledge of a variety of topics and development of specialised skills including Navigation and international A shoal or sandbar (also called sandbank) is a somewhat Linear Landform within or extending into a body of Water, In nautical terminology a reef is a rock, sandbar, or other feature lying beneath the surface of the water (six fathoms or less at low water Navigation is the process of reading and controlling the movement of a craft or vehicle from one place to another It therefore applies to a silt accumulation that shallows the entrance to or the course of a river or creek. Silt is Soil or rock derived Granular material of a Grain size between sand and clay "Riverine" redirects here For the use of that term in Maritime geography, see there A stream is a body of Water with a current, confined within a bed and stream-banks

Contents

Sandbars and longshore bars

A sandbar off Suffolk County, Long Island, New York, August 2006.
A sandbar off Suffolk County, Long Island, New York, August 2006. Suffolk County is a county located in the US state of New York. Long Island is an island located in southeastern New York, USA, its western shores directly across from Manhattan, from which the island stretches New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous
Shoals in the Mississippi River at Arkansas and Mississippi.
Shoals in the Mississippi River at Arkansas and Mississippi. The Mississippi River is the second longest River in the United States, with a length of from its source in Lake Itasca in Minnesota to Arkansas ( is a state located in the southern region of the United States. Mississippi ( is a state located in the Deep South of the United States

This bar forms (sometimes seaward of a trough) where the waves are breaking, because the breaking waves set up a shoreward current with a compensating counter-current along the bottom. In geology a trough generally refers to a linear structural depression that extends laterally over a distance while being less steep than a trench. Sand carried by the offshore moving bottom current is deposited where the current reaches the wave break (Bascom, 1980). Other longshore bars may lie further offshore, representing the break point of even larger waves, or the break point at low tide.

Harbour and river bars

A harbour or river bar is a sedimentary deposit formed at a harbour entrance or river mouth by the deposition of sediment or the action of waves on the sea floor or adjacent beaches. A harbor or harbour (see spelling differences) or haven, is a place where ships may shelter from the Weather or are stored "Riverine" redirects here For the use of that term in Maritime geography, see there Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of A bar can form a dangerous obstacle to shipping, preventing access to the river or harbour in unfavourable weather conditions or at some states of the tide. Characteristics A tide is a repeated cycle of sea level changes in the following stages Over several hours the water rises or advances up a beach in the flood Where beaches are suitably mobile, or the river’s suspended and/or bed loads are large enough, wave action can build up a bar to completely block a river mouth, damming the river, preventing access for boats or shipping, and causing flooding in the lower reaches of the river. Suspended Load hweuwqrfor the fine particles that are light enough to be carried in a Stream without touching the Stream bed. The term Bed load describes particles in a flowing fluid (usually a river that are transported along the bed This situation will persist until the bar is eroded by the sea, or the dammed river develops sufficient head to break through the bar. Coastal erosion is the wearing away of land or the removal of Beach or Dune Sediments by Wave action tidal currents, wave currents Hydraulic head is a specific measurement of water pressure or Total energy per Unit weight above a Geodetic datum.

Shoals as geological units

In addition to longshore bars discussed above that are relatively small features of a beach, the term shoal can be applied to larger geological units that form off a coastline as part of the process of coastal erosion. These include spits and baymouth bars that form across the front of embayments and rias. A spit is a deposition Landform found off Coasts. At one end spits connect to land while at the far end they exist in open water A ria is a Landform, often referred to as a drowned river valley. A tombolo is a bar that forms an isthmus between an island or offshore rock and a mainland shore. A tombolo is a deposition Landform such as a spit or bar which is attached to the mainland by a narrow piece of land An isthmus is a narrow strip of land connecting two larger land areas An island (ˈaɪlənd or isle (/ˈaɪl/ is any piece of land that is completely surrounded by water in two dimensions above high tide and isolated from other significant Mainland is usually the Continental part of a region as opposed to the Islands nearby

The largest of the geological units of this kind is a barrier island, such as occur along the East Coast of the United States, along the Gulf coast, along the southern coast of Belize and many other locations worldwide. The East Coast of the United States, also known as the "Eastern Seaboard" or "Atlantic Seaboard" refers to the easternmost coastal states in the central and northern The Gulf of Mexico ( Spanish: Golfo de México) is the ninth largest Body of water in the world Belize (bəˈliːz formerly British Honduras, is a country in Central America.

In places of re-entrance along a coastline (such as inlets, coves, rias, and bays), sediments carried by a longshore current will fall out where the current dissipates, forming a spit. The coast is defined as the part of the land adjoining or near the Ocean. An inlet is a narrow body of water between islands or leading inland from a larger body of water often leading to an enclosed body of water such as a sound, bay, A cove is a circular or Oval Coastal Inlet with a narrow entrance Longshore drift (sometimes known as shore drift, LSD or littoral drift) is a geological process by which Sediments such as sand A spit is a deposition Landform found off Coasts. At one end spits connect to land while at the far end they exist in open water An area of water isolated behind a large bar is called a lagoon. A lagoon is a body of comparatively shallow salt or Brackish water separated from the deeper Sea by a shallow or exposed sandbank, coral Over time, lagoons may silt up, becoming salt marshes. A salt marsh is a type of Marsh that is a transitional intertidal between land and salty or Brackish water (e

In some cases shoals may be precursors to beach expansion and dunes formation, providing a source of windblown sediment to augment such beach or dunes landforms. [1]

Federal Laws

Examples

See also

Line notes

  1. ^ Mirko Ballarini, Optical Dating of Quartz from Young Deposits, IOS Press, 2006 146 pages, ISBN 158603616

References

Dictionary

shoal

-noun

  1. A large number of fish of the same species swimming together.
  2. A sandbank or bar creating a shallow.
  3. A large group of marine invertebrates or squid that move as a unit.
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