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: Coronado, California; Nahant, Massachusetts; 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 technically, geographers now believe that Chesil Beach (which connects the island to the mainland) is actually a barrier beach which has moved eastwards, rather than a tombolo, which would have been formed by the effect of the island on waves.

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

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