floating island

Uros island

A floating island is a mass of floating aquatic plants, mud, and peat ranging in thickness from a few inches to several feet. Floating islands are a common natural phenomenon that are found in many parts of the world. They exist less commonly as a man-made phenomenon. Floating islands are generally found on marshlands, lakes, and similar wetland locations, and can be many hectares in size.

Natural

When they occur naturally they are sometimes referred to as tussocks, floatons, or sudds. Natural floating islands are composed of vegetation growing on a buoyant mat consisting of plant roots or other organic detritus.

They typically occur when growths of cattails, bulrush, sedge, and reeds extend outward from the shoreline of a wetland area. As the water gets deeper the roots no longer reach the bottom, so they use the oxygen in their root mass for buoyancy, and the surrounding vegetation for support to retain their top-side-up orientation^{[citation needed]}. The area beneath these floating mats is exceptionally rich in aquatic lifeforms. Eventually, storm events tear whole sections free from the shore, and the islands thus formed migrate around a lake with changing winds, eventually either reattaching to a new area of the shore, or breaking up in heavy weather.

Natural floating islands may have been the source of many "disappearing island" legends, such as those surrounding the Isle of Avalon.

Explosive volcanic eruptions may create pumice rafts, that can float on the ocean for months or even years before becoming fully saturated and sinking. The larger rafts often wind up having grasses and palm trees growing on them.

Artificial

Floating artificial islands are generally made of bundled reeds, and the best known examples are those of the Uros people of Lake Titicaca, Peru, who build their villages upon what are in effect huge rafts of bundled totora reeds. The Uros originally created their islands to prevent attacks by their more aggressive neighbours, the Incas and Collas. The Aztec capital, Tenochtitlan, was surrounded with chinampas, small artificial islands used for agriculture known as "floating gardens" (though not really floating). Spiral Island was a more modern one-person effort of constructing an artificial floating island in Mexico.

The British wartime Project Habakkuk proposed the construction of aircraft carriers made of ice-like Pykrete. Its size and speed made it more an artificial iceberg or island than a ship.

Commercial development of floating islands has begun taking place. A commercially-produced floating island was installed in the river otter enclosure at Zoo Montana in 2007. [1]

A company called Floating Islands International licenses technology for creating floating islands to a variety of organizations.^[1]

"Forbes Island," in San Francisco, is a former houseboat (converted to a restaurant) that was built to resemble an island.

Locations

• Lake Titicaca, Bolivia and Peru
• Lake Kyoga, Uganda
• Loktak Lake, India
• Umbagog Lake, Maine, United States
• Lake Visitor, Montenegro
• Vlasina Lake, Serbia
• Lake Upemba, Democratic Republic of the Congo
• Lake Chad, Africa
• Lake Finicha'a, Ethiopia

External links

• Inca Heartland – A site with numerous pictures of floating artificial islands on Lake Titicaca.
• Tourism Keeping Peruvian Islands Afloat article by Roderick Eime
• "Disagreement on whether to tether island that floats free in Massachusetts pond" – San Francisco Chronicle
• Floating on an island

References

1. ^ http://features.csmonitor.com/environment/2009/05/20/how-to-clean-up-a-lake-floating-islands-might-be-the-answer/