Shoal

A shoal, sandbar (or just bar in context), sandbank or gravelbar is a somewhat linear landform within or extending into a body of water, typically composed of sand, silt or small pebbles. A spit or sandspit is a type of shoal. Shoals are characteristically long and narrow (linear) and develop where a stream or ocean current promotes deposition of granular material, resulting in localized shallowing (shoaling) of the water. Shoals can appear in the sea, in a lake, or in a river. Alternatively a bar may separate a lake from the sea, as in the case of an ayre. 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). 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 metres in a small stream to marine depositions stretching for hundreds of kilometres along a coastline, often called barrier islands.

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, with a depth of water of 6 fathoms (11 metres) or less. It therefore applies to a silt accumulation that shallows the entrance to the course of a river or creek.

Read more about Shoal:  Shoaling, Sandbars and Longshore Bars, Harbour and River Bars, Shoals As Geological Units, Human Habitation

Other articles related to "shoal":

Shoal - Human Habitation
... Since prehistoric times humans have chosen some shoals as a site of habitation ... In some early cases the locations provided easy access to exploit marine resources ...
Shoal Bay, British Columbia
... Shoal Bay was a cannery town in the Discovery Islands region of the South Coast of British Columbia, Canada, located on the northeast side of East Thurlow ... town (1895-1900) on the western coast of Canada, Shoal Bay was a hub for mining and forestry ... Shoal bay survived as a small town supporting a school and market until the 1950s when the school closed and families moved to more developed communities such as Campbell River ...
Shoal Lake, Manitoba (rural Municipality)
... Shoal Lake is a rural municipality located in the Westman Region of Manitoba, Canada ... The separately administered town of Shoal Lake lies within the municipality, just southeast of its centre ...
Metis Shoal
... Metis Shoal is a shoal at the top of a submarine volcano, located between the islands of Kao and Late in Tonga ... On 7 December 2006 the Royal New Zealand Air Force (RNZAF) flew over Metis Shoal and Home Reef at the request of volcanologists from the Institute of Geological Nuclear sciences (IGNS) to take ...
Ship John Shoal Light - History
... Ship John Shoal took its name from an incident in 1797 in which the John, captained by a Robert Folger, ran aground while on the way from Hamburg, Germany to Philadelphia ... which the rescued passengers were taken.) Completion of the original Brandywine Shoal Light in 1850 led the Lighthouse Board to draw up plans to erect similar lights at Ship John Shoal and Cross Ledge ... Congress appropriated funds toward the construction of a caisson light on the shoal ...

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