Tied island

Last updated
View from the Isle of Portland looking towards the mainland of Great Britain. Chesil Beach on the left connects the tied island to the mainland. Uk dor portharbour.JPG
View from the Isle of Portland looking towards the mainland of Great Britain. Chesil Beach on the left connects the tied island to the mainland.
St Ninian's Isle, a tied island during all but the very highest tides. Tombolo St Ninians 5940.JPG
St Ninian's Isle, a tied island during all but the very highest tides.

Tied islands, or land-tied islands as they are often known, are landforms consisting of an island that is connected to land only by a tombolo: a spit of beach materials connected to land at both ends. St Ninian's Isle, in the Shetland Islands off the north coast of Scotland, is an example of this; it was once an island but is now linked to the Mainland. Other examples include: Maury Island, Washington in the Puget Sound, Coronado, California and Nahant, Massachusetts in the U.S.; Barrenjoey, New South Wales in Australia; and Wedge Island in Western Australia.

Contents

The Isle of Portland is also described as a tied island, although geographers now believe that Chesil Beach (which connects the island to the mainland) is a barrier beach that has moved eastwards, rather than a tombolo, which would have been formed by the effect of the island on waves.

Paniquian Island (also known as Isla Boquete) is a tied island in Puerto Galera, a popular tourist destination in the Philippines. The island is connected to the main island of Mindoro by a small tombolo that is only submerged a few times per year.

See also

Related Research Articles

Archipelago A group of islands

An archipelago, sometimes called an island group or island chain, is a chain, cluster or collection of islands, or sometimes a sea containing a small number of scattered islands.

Island Any piece of sub-continental land that is surrounded by water

An island or isle is any piece of subcontinental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. Sedimentary islands in the Ganges delta are called chars. A grouping of geographically or geologically related islands, such as the Philippines, is referred to as an archipelago.

Adams Bridge Landform off coast of Sri Lanka

Adam's Bridge, also known as Rama's Bridge or Rama Setu, is a chain of limestone shoals, between Pamban Island, also known as Rameswaram Island, off the south-eastern coast of Tamil Nadu, India, and Mannar Island, off the north-western coast of Sri Lanka. Geological evidence suggests that this bridge is a former land connection between India and Sri Lanka.

Islet Very small island

An islet is a very small island. Most definitions are not precise, but some suggest that an islet has little or no vegetation, and cannot support human habitation. They may be made of rock, sand, and/or coral, may be permanent or tidal, and may exist in the sea, rivers, or any other body of water.

Isle of Portland Human settlement in England

The Isle of Portland is a tied island, 6 kilometres (4 mi) long by 2.7 kilometres (1.7 mi) wide, in the English Channel. Portland is 8 kilometres (5 mi) south of the resort of Weymouth, forming the southernmost point of the county of Dorset, England. A barrier beach called Chesil Beach joins it to the mainland. The A354 road passes down the Portland end of the beach and then over the Fleet Lagoon by bridge to the mainland. Portland and Weymouth together form the borough of Weymouth and Portland. The population of Portland is 12,797.

Jurassic Coast World Heritage Site on the coast of southern England

The Jurassic Coast is a World Heritage Site on the English Channel coast of southern England. It stretches from Exmouth in East Devon to Studland Bay in Dorset, a distance of about 96 miles (154 km), and was inscribed on the World Heritage List in mid-December 2001.

Tombolo Deposition landform in which an island is connected to the mainland by a sandy isthmus

A tombolo is a sandy isthmus. A tombolo, from the Italian tombolo, meaning 'pillow' or 'cushion', and sometimes translated as 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. Once attached, the island is then known as a tied island.

Chesil Beach shingle beach in Dorset, southern England

Chesil Beach, sometimes called Chesil Bank, in Dorset, southern England is one of three major shingle structures in Britain. Its name is derived from the Old English ceosel or cisel, meaning "gravel" or "shingle". It runs for a length of 29 kilometres (18 mi) from West Bay to the Isle of Portland and in places is up to 15 metres (50 ft) high 200 metres (660 ft) wide. Behind the beach is the Fleet, a shallow tidal lagoon. Both are part of the Jurassic Coast and a UNESCO World Heritage Site, and together form an SSSI and Ramsar Site.

Shoal Natural submerged sandbank that rises from a body of water to near the surface

In oceanography, geomorphology, and earth sciences, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material, and rises from the bed of a body of water to near the surface. Often it refers to those submerged ridges, banks, or bars that rise near enough to the surface of a body of water as to constitute a danger to navigation. Shoals are also known as sandbanks, sandbars, or gravelbars. Two or more shoals that are either separated by shared troughs or interconnected by past or present sedimentary and hydrographic processes are referred to as a shoal complex.

Spit (landform) Coastal bar or beach landform deposited by longshore drift

A spit or sandspit is a deposition bar or beach landform off coasts or lake shores. It develops in places where re-entrance occurs, such as at a cove's headlands, by the process of longshore drift by longshore currents. The drift occurs due to waves meeting the beach at an oblique angle, moving sediment down the beach in a zigzag pattern. This is complemented by longshore currents, which further transport sediment through the water alongside the beach. These currents are caused by the same waves that cause the drift.

Langness Peninsula Human settlement in the United Kingdom

Langness is a peninsula which protrudes two kilometres at the southern extremity of the Isle of Man. Signifying a cape or extended promontory, Langness" literally means "long promontory" in Old Norse. Formerly an island, Langness was eventually joined to the mainland by the movement and deposition of material along Castletown Bay to form a tombolo. The small community of Derbyhaven is situated on the east coast of this isthmus, which lies close to Castletown, Isle of Man.

St Ninians Isle Island in Shetland, United Kingdom

St Ninian's Isle is a small tied island connected by the largest tombolo in the UK to the south-western coast of the Mainland, Shetland, in Scotland. It is part of the civil parish of Dunrossness on the South Mainland. The tombolo, known locally as an ayre from the Old Norse for "gravel bank", is 500 metres long. During the summer the tombolo is above sea level and accessible to walkers. During winter, stronger wave action removes sand from the beach so that it is usually covered at high tide, and occasionally throughout the tidal cycle, until the sand is returned the following spring. Depending on the definition used, St. Ninian's is thus either an island, or a peninsula; it has an area of about 72 hectares.

Monte Argentario Comune in Tuscany, Italy

Monte Argentario is a comune (municipality) and a peninsula belonging to the Province of Grosseto in the Italian region Tuscany, located about 150 kilometres (93 mi) south of Florence and about 35 kilometres (22 mi) south of Grosseto. The peninsula is connected with the mainland by three spits of land which form two lagoons, the Laguna di Ponente on the west side and the Laguna di Levante on the east side of the middle dam. The two main villages on Monte Argentario are Porto Santo Stefano, chief town, facing north, and Porto Ercole facing south.

Bodie Island is a long, narrow barrier peninsula that forms the northernmost portion of the Outer Banks. The land that is most commonly referred to as Bodie Island was at one time a true island, but in 1811 Roanoke Inlet, which had separated it from the Currituck Banks in the north, closed. As a result, the Currituck Banks and Bodie Island are now one contiguous peninsula, joined together at the Nags Head area, where the inlet once flowed. Today, either name can be used to refer to peninsula as a whole, but both portions colloquially retain their historical names.

South Walls island in United Kingdom

South Walls is an inhabited island adjacent to Hoy in Orkney, Scotland. The name is a corruption of "Sooth Was", which means the "southern voes" - as with Kirkwall, it was assumed that it was a mispronunciation of "walls".

Geography of Dorset

Dorset is a county located in the middle of the south coast of England. It lies between the latitudes 50.512°N and 51.081°N and the longitudes 1.682°W and 2.958°W, and occupies an area of 2,653 km². It spans 90 kilometres (56 mi) from east to west and 63 kilometres (39 mi) from north to south.

References