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 mainland or another island 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 since 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 United States; Barrenjoey, New South Wales, in Australia; Paratutae Island, in New Zealand; Mount Hakodatein Japan, Howth Head, in Ireland; Wedge Island, in Western Australia; Cheung Chau, in Hong Kong; and Davaar Island, Campbeltown, Scotland.

Contents

The Isle of Portland, in England, is also described as a tied island, but 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, which is submerged only a few times per year.

See also

Related Research Articles

Islands of the Clyde Scottish island group

The Islands of the Firth of Clyde are the fifth largest of the major Scottish island groups after the Inner and Outer Hebrides, Orkney and Shetland. They are situated in the Firth of Clyde between Ayrshire and Argyll and Bute. There are about forty islands and skerries. Only four are inhabited, and only nine are larger than 40 hectares. The largest and most populous are Arran and Bute. They are served by dedicated ferry routes, as are Great Cumbrae and Holy Island. Unlike the isles in the four larger Scottish archipelagos, none of the isles in this group are connected to one another or to the mainland by bridges.

Islet Very small island

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

Isle of Portland Tied island in Dorset, 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. The southern tip, Portland Bill lies 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 Portland with mainland England. The A354 road passes down the Portland end of the beach and then over the Fleet Lagoon by bridge to the mainland. 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 or shingle isthmus. A tombolo, from the Italian tombolo, meaning 'pillow' or 'cushion', and sometimes translated incorrectly as ayre, is a deposition landform by which an island becomes 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, England

Chesil Beach in Dorset, England is one of three major shingle beach 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 and 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 geoscience, 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. It often 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.

Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.

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.

Mainland, Orkney Main island of the Orkney Islands, Scotland

The Mainland, also known as Hrossey and Pomona, is the main island of Orkney, Scotland. Both of Orkney's burghs, Kirkwall and Stromness, lie on the island, which is also the heart of Orkney's ferry and air connections.

Shapinsay Island and (until 1975) civil parish in Orkney Islands, Scotland

Shapinsay is one of the Orkney Islands off the north coast of mainland Scotland. There is one village on the island, Balfour, from which roll-on/roll-off car ferries sail to Kirkwall on the Orkney Mainland. Balfour Castle, built in the Scottish Baronial style, is one of the island's most prominent features, a reminder of the Balfour family's domination of Shapinsay during the 18th and 19th centuries; the Balfours transformed life on the island by introducing new agricultural techniques. Other landmarks include a standing stone, an Iron Age broch, a souterrain and a salt-water shower.

Skerry A rocky island smaller than an islet

A skerry is a small rocky island, or islet, usually too small for human habitation. It may simply be a rocky reef. A skerry can also be called a low sea stack.

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.

South Walls

South Walls, often referred to as 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".

Ayre (landform) Shingle beaches in Orkney and Shetland

An ayre is the name used for shingle beaches found in Orkney, Shetland, the Isle of Man, Lancashire, Cumbria and Northumbria. The word is derived from the Old Norse eyrr, meaning a shingle beach or gravelly place, and may be applied to ordinary beaches, cliff-foot beaches such as the Lang Ayre in Northmavine, Shetland, spits, bars or tombolos, but only if formed of shingle. More than 130 such shingle beaches are named on Ordnance Survey maps of Shetland, but far fewer in Orkney, where most beaches are formed of sand. The word in its Old Norse form is common in Iceland, and it also occurs in a few place names in the north and west of the Scottish mainland which had a strong Norse influence, such as Eriboll and in the names of several shingle banks—Salt Ayre, Green Ayre, Stake Ayre, Rabbit Ayre and Whinny Ayre—in the tidal reach of the River Lune at Lancaster.

Los Morrillos (Cabo Rojo) Cape and tombolo landform located in Puerto Rico

Los Morrillos de los Cabos Rojos or more commonly known as Los Morrillos de Cabo Rojo, is a cape and tombolo landform located in southwestern Puerto Rico in the municipality of Cabo Rojo. Los Morrillos is an excellent example of a tombolo, or a tied island, with two sand pits. The cape resembles a letter Y with its two promontories or morrillos being connected through sand pits which enclose a saltwater lagoon. The landform was designated a National Natural Landmark in 1980, and the site includes mangroves, beaches, important bird nesting areas, limestone caves, cliffs and rock formations. The reddish-colored limestone cliffs give the name to the town and municipality of Cabo Rojo.

References