- published: 25 Mar 2015
- views: 12972
An atoll (/ˈætɒl/, /ˈætɔːl/, /ˈætoʊl/, /əˈtɒl/, /əˈtɔːl/ or /əˈtoʊl/), sometimes called a coral atoll, is a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely. There may be coral islands/cays on the rim. The coral of the atoll often sits atop the rim of an extinct seamount or volcano which has eroded or subsided partially beneath the water. The lagoon forms over the volcanic crater or caldera while the higher rim remains above water or at shallow depths that permit the coral to grow and form the reefs. For the atoll to persist, continued erosion or subsidence must be at a rate slow enough to permit reef growth upwards and outwards to replace the lost height.
The word atoll comes from the Dhivehi (an Indo-Aryan language spoken on the Maldive Islands) word atholhu (Dhivehi: އަތޮޅު, [ˈət̪ɔɭu]), meaning an administrative subdivision.OED Its first recorded use in English was in 1625 as atollon – Charles Darwin recognized its indigenous origin and coined, in his The Structure and Distribution of Coral Reefs, the definition of atolls as "circular groups of coral islets" that is synonymous with "lagoon-island".
Atolls begin as an underwater volcanoes called seamounts. Over time and many eruptions the seamount grows until it rises above the water and becomes an island. Corals grow around the island and, over geologic time, the volcano goes dormant and sinks, but the coral reefs remain and continue to grow faster than the island sinks, eventually creating an island ring made of coral around a central lagoon where the volcano used to be. To learn more, check out our online coral reef ecology curriculum: http://www.lof.org/education/portal/
Join Steve and Manjula in the South Pacific. Natural beauty, meets bird and sea life, in the wilds of the South Pacific atolls.
your 1st step using Atoll this video just to show the effect of changing power , height and tilting So some steps are skipped and another parameters are neglected https://www.facebook.com/waleedelsafoury.fans
more videos in HD: http://www.youtube.com/TheCentralnuclear Material: * Fragmento "TRINITY AND BEYOND, THE ATOMIC BOMB MOVIE" dirigida por Peter Kuran y narrado por William Shatner. * Nuclear tests channel Cruces de la operación fue una serie de armas nucleares las pruebas realizadas por el Estados Unidos en el atolón de Bikini , a mediados de 1946. Fue la primera prueba de un arma nuclear desde la Trinidad prueba nuclear en julio de 1945, y la primera detonación de un dispositivo nuclear desde el bombardeo atómico de Nagasaki el 9 de agosto de 1945. Su propósito fue investigar el efecto de las armas nucleares en los buques de guerra. Encrucijada consistieron en dos detonaciones, cada uno con un rendimiento de 23 kilotones de TNT (96 terajoules ): Capaz fue detonada a una altura de 52...
Learn practically 4G(LTE) site planning with Atoll tool.
This is my first online tutorial and its about the green field planning... i will appreciate if you add suggestions or may be your opinion about the video.If you like the video than please click on like button..Please subscribe for future comparisons, demos, and tests of the different planning tools....
01 Le Photographe exorciste 02 Gazotte 03 Le voleur dextase 04 L'araignee-mal (1)Imazine le temps (2)L'araignee-mal (3)Les robots debiles (4)Le cime tiere de plastique
atoll video for beginners must watch and share with your friends
Scenes and views of the island during my visit in December 2011. Includes dives on 2 wrecks from the atomic testing in the 50's. Look on www.TropicalSailingLife.com for more about cruising details.
Gimme some to dance to
For one priceless moment in the whole history of man
All the people on this Earth are truly one
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Are truly one
All the people on this Earth are truly one