Tied island

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.

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.

The Isle of Portland is also referred to 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.

See also

• Islands portal

References

• Glossary of geology and related sciences. Jesse V. Howell, American Geological Institute. 1962.
• Some Coastal Landform Definitions. Matthew Flinders, Villanova College, Queensland.

External links

• Media related to Tied islands at Wikimedia Commons

Coastal geography
Landforms	Anchialine pool Archipelago Atoll Avulsion Ayre Barrier island Bay Baymouth bar Bight Bodden Brackish marsh Cape Channel Cliff Coast Coastal plain Coastal waterfall Continental margin Continental shelf Coral reef Cove Dune cliff-top Estuary Firth Fjard Fjord Freshwater marsh Fundus Gat Geo Gulf Gut Headland Inlet Intertidal wetland Island Islet Isthmus Lagoon Machair Marine terrace Mega delta Mouth bar Mudflat Natural arch Peninsula Reef Regressive delta Ria River delta Salt marsh Shoal Shore Skerry Sound Spit Stack Strait Strand plain Submarine canyon Tidal island Tidal marsh Tide pool Tied island Tombolo Windwatt
Beaches	Beach cusps Beach evolution Coastal morphodynamics Beach ridge Beachrock Pocket beach Raised beach Recession Shell beach Shingle beach Storm beach Wash margin
Processes	Blowhole Cliffed coast Coastal biogeomorphology Coastal erosion Concordant coastline Current Cuspate foreland Discordant coastline Emergent coastline Feeder bluff Fetch Flat coast Graded shoreline Headlands and bays Ingression coast Large-scale coastal behaviour Longshore drift Marine regression Marine transgression Raised shoreline Rip current Rocky shore Sea cave Sea foam Shoal Steep coast Submergent coastline Surf break Surf zone Surge channel Swash Undertow Volcanic arc Wave-cut platform Wave shoaling Wind wave Wrack zone
Management	Accretion Coastal management Integrated coastal zone management Submersion
Related	Bulkhead line Grain size boulder clay cobble granule pebble sand shingle silt Intertidal zone Littoral zone Physical oceanography Region of freshwater influence
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