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A spit is a deposition
Deposition (geology)

Deposition is the Geology process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment gravity flows, Transportation previously Erosion sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of sediment....
 landform
Landform

In the earth sciences and geology sub-fields a landform or physical feature comprises a geomorphology unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography....
 found off coasts. At one end, spits connect to land, while at the far end they exist in open water.






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Dspit
Spit Diagram
A spit is a deposition
Deposition (geology)

Deposition is the Geology process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment gravity flows, Transportation previously Erosion sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of sediment....
 landform
Landform

In the earth sciences and geology sub-fields a landform or physical feature comprises a geomorphology unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography....
 found off coasts. At one end, spits connect to land, while at the far end they exist in open water. A spit is a type of bar
Bar (landform)

A shoal or sandbar is a somewhat linear landform within or extending into a body of water, typically composed of sand, silt or small pebbles....
 or beach
Beach

File:MiamiSouthBeachPanoramaEdit.jpgA beach is a geology landform along the shoreline of a body of water. It usually consists of loose particles which are often composed of Rock , such as sand, gravel, shingle beach, pebbles, or cobble....
 that develops where a re-entrant occurs, such as at cove's headlands, by the process of longshore drift
Longshore drift

Longshore drift is a geology process by which sediments such as sand or other materials, move along a beach shore. It uses the process of swash to push the material up the beach and backwash down the beach; until it reaches a groyne or another obstacle....
. Longshore drift (also called littoral drift) occurs due to waves meeting the beach at an oblique angle, and backwashing perpendicular to the shore, moving sediment down the beach in a zigzag pattern. Longshore drifting is complemented by longshore currents, which transport sediment through the water alongside the beach. These currents are set in motion by the same oblique angle of entering waves that causes littoral drift and transport sediment in a similar process.

Hydrology and geology


Where the direction of the shore inland reenters, or changes direction, such as at a headland, the longshore current spreads out or dissipates. No longer able to carry the full load, much of the sediment is dropped. This is also known as deposition. This submerged bar of sediment allows littoral drift to continue to transport in the direction the waves are breaking, forming an above-water spit. Without the complementary process of littoral drift, the bar would not build above the surface of the waves becoming a spit and would instead be leveled off underwater.

Spits occur when longshore drift
Longshore drift

Longshore drift is a geology process by which sediments such as sand or other materials, move along a beach shore. It uses the process of swash to push the material up the beach and backwash down the beach; until it reaches a groyne or another obstacle....
 reaches a section of headland
Headland

A headland is land surrounded by water on three sides.Headland can also refer to:*Headlands and bays*headLand, an Australian television series...
 where the turn is greater than 30 degrees. They will continue out into the sea until water pressure (such as from a river) becomes too much to allow the sand to deposit. The spit may then be grown upon and become stable and often fertile. A spit may be considered a specialized form of a shoal
Shoal

Things known as shoal, shoals or shoaling include:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping...
. As spits grow, the water behind them is sheltered from wind and waves, and a salt marsh is likely to develop.

Wave refraction can occur at the end of a spit, carrying sediment around the end to form a hook or recurved spit. Wave refraction in multiple directions will cause a complex spit to form. Incoming waves that come in a direction other than obliquely along the spit will halt the growth of the spit, shorten it or eventually destroy it entirely.

The sediments that make up spits come from a variety of sources including rivers and eroding bluffs, and changes there can have a large impact on spits and other coastal landforms. Activities such as logging and farming upstream can increase the sediment load of rivers, which may hurt the intertidal environments around spits by smothering delicate habitat. Roads or bulkheads built along bluffs can drastically reduce the volume of sediment eroded, so that not enough material is being pushed along to maintain a given spit.

If the supply of sediment is interrupted the sand at the neck (landward side) of the spit may be moved towards the head, eventually creating an island
Island

An island or isle is any piece of land that is surrounded by water. Very small islands such as emergent land features on atolls are called islets....
. If the supply isn't interrupted, and the spit isn't breached by the sea (or, if across an estuary, the river) the spit may become a bar
Bar (landform)

A shoal or sandbar is a somewhat linear landform within or extending into a body of water, typically composed of sand, silt or small pebbles....
, with both ends joined to land, and form a lagoon
Lagoon

A lagoon is a body of comparatively shallow sea water or brackish water separated from the deeper sea by a shallow or exposed Bar , reef, or similar feature....
 behind the bar. If an island lies offshore near where the coast changes direction, and the spit continues to grow until it connects the island to the mainland, it is then called a tombolo
Tombolo

A tombolo or sometimes ayre is a deposition landform in which an island is attached to the mainland by a narrow piece of land such as a spit or bar ....
.

When talking about spits, the end of the spit attached to the mainland is called the proximal end and the end jutting out into the stretch of water is called the distal end.

Spits around the world

The longest spit in the World is the Curonian Spit
Curonian Spit

The Curonian Spit is a 98 km long, thin, curved sand-dune Spit that separates the Curonian Lagoon from the Baltic Sea....
 in the Baltic Sea
Baltic Sea

The Baltic Sea is a brackish inland sea 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 Denmark islands....
, famous by its unique landscape and ecosystem. It is almost 100km long, evenly divided between Russia
Russia

Russia , or the Russian Federation , is a list of countries spanning more than one continent country extending over much of northern Eurasia....
 and Lithuania
Lithuania

Lithuania , officially the Republic of Lithuania is a country in Northern Europe, the southernmost of the three Baltic states. Situated along the southeastern shore of the Baltic Sea, it shares borders with Latvia to the north, Belarus to the southeast, Poland, and the Russian exclave of Kaliningrad Oblast to the southwest....
.

The largest spit in the United States is the Dungeness Spit
Dungeness Spit

Dungeness Spit is a long spit jutting out from the northern edge of the Olympic Peninsula in northeastern Clallam County, Washington, into the Strait of Juan de Fuca....
 on the Olympic Peninsula
Olympic Peninsula

The Olympic Peninsula is the large arm of land in western Washington state that lies across Puget Sound from Seattle, Washington. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, and the east by Puget Sound and the Hood Canal....
 in Washington
Washington

Washington is a U.S. state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute....
 (8.9Km).

Farewell Spit
Farewell Spit

Farewell Spit is a narrow sand Spit situated at , at the northern end of the South Island of New Zealand. Known to the Maori as Tuhuroa, it runs eastwards from Cape Farewell, New Zealand, the island's northernmost point....
 in New Zealand
New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous Islands of New Zealand, most notably Stewart Island/Rakiura and the Chatham Islands....
, at 32km, is one of the longest in the world. Farewell Spit, in the North West corner of the South Island
South Island

The South Island is the larger of the two major Islands of New Zealand of New Zealand, the other being the more populous North Island. The Maori name for the South Island, Te Wai Pounamu, meaning "The Water/s of Greenstone" , possibly evolved from Te Wahi Pounamu which means "The Place Of Greenstone"....
 is believed to be caused by the strong prevailing winds and currents bringing sand eroded from the Southern Alps
Southern Alps

The Southern Alps is a mountain range which runs along the western side of the South Island of New Zealand. It forms a natural dividing range along the entire length of the South Island....
 of the South Island and depositing these into Golden Bay.

Spits in the UK are caused by prevailing South-Westerly winds, which give the spits their direction. However, when the direction of the wind changes for a short while the spit may change in direction for a short while forming a hook. Many spits have hooked or curved ends.

Human settlement patterns


Since prehistory humans have chosen certain spit formations as sites for human habitation. In some cases such as Chumash
Chumash

The Chumash are Native Americans in the United States people who historically inhabit chiefly central and southern coastal regions of California, in portions of what is now San Luis Obispo, Santa Barbara, California, Ventura, California and Los Angeles counties, extending from Morro Bay in the north to Malibu, California in the south....
 Native American
Indigenous peoples of the Americas

The indigenous peoples of the Americas are the pre-Columbian inhabitants of the Americas, their descendants, and many ethnic groups who identify with those peoples....
 prehistorical settlement, these sites have been chosen for proximity to marine resource exploitation; for example, the Chumash settlement on the Morro Bay sandspit is one such location.

See also

  • List of spits (landforms)
    List of spits (landforms)

    There are many examples of spit around the world. Some of which include:...
  • Shoal
    Shoal

    Things known as shoal, shoals or shoaling include:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping...