Types Of Island.....

Continental Islands

Angel Island in the San Francisco Bay.

Continental islands are bodies of land that lie on the continental shelf of a continent. Examples include Greenland and Sable Island off North America; Barbados and Trinidad off South America; Great Britain, Ireland and Sicily off Europe; Sumatra and Java off Asia; and New Guinea and Tasmania off Australia.

A special type of continental island is the microcontinental island, which results when a continent is rifted. Examples are Madagascar off Africa; the Kerguelen Islands; and some of the Seychelles.

Another subtype is an island or bar formed by deposition of sediment where a water current loses some of its carrying capacity. An example is barrier islands, which are accumulations of sand deposited by sea currents on the continental shelf. Another example is islands in river deltas or in large rivers. While some are transitory and may disappear if the volume or speed of the current changes, others are stable and long-lived.

Example: Sable Island

Sable Island is a sand bar - 42 km long and roughly 1.5 km wide - located far offshore, approximately 160 km southeast of Canso, Nova Scotia, the nearest landfall. The island has been the focus of human activities, imagination and speculation for roughly 500 years. Shipwrecks, wild horses, seabirds and seals, and inaccessibility have endowed this narrow wind-swept sliver of sand with a special mystique. The island is the subject of extensive scientific research and of numerous documentary films, books and magazine articles.

Sable Island, with a surface area of about 3400 ha, has a topography comprised of beaches, sand dunes, inland fields of grass and heath, and freshwater ponds. The physiography of the island is the result of atmospheric and oceanic influences. The shape and position of the dunes reflect the prevailing westerly wind direction and storm trends. Ocean currents, waves, and tides modify the width and contour of the beaches and change the dimensions of east and west spits.
A variety of plants and animals are found on Sable Island. About 40% of the land surface area is vegetated. Over 175 plant species are found in several distinctive plant communities. These include the sandwort colonies of the east and west ends of the island; shrub-heath and cranberry communities dominated by crowberry, bayberry, wild rose, blueberry and cranberry; and richly vegetated freshwater pond and pond edge communities. In summer and autumn the island is cloaked with lush, green vegetation and wildflowers (including six species of orchid); in winter and early spring the dunes are rather bleak, grey and windswept, and appear deceptively devoid of vegetation. Except for one small pine surviving from a planting near the weather station some forty years ago, there are no trees on the island.

D`Artz : Types
Sable Island