Coral, rock, silt, sand, rubble, sponges, and seaweed all contribute to the architecture of the Cocos (Keeling) Islands.
Published Dec 27, 2011
The Maldives rise just a few meters above the surrounding ocean.
Published Jan 15, 2017
These two images of the Tuamotu Archipelago, French Polynesia, illustrate diversity in the morphology of atolls, one of the major types of coral reef formations. A typical atoll structure is a lagoon surrounded by a closed rim of cays and shallow spillways that control the exchange of water between the ocean and the lagoon. However, like human beings, this general scheme may vary according to the history of each individual atoll, resulting in a high diversity of morphology, especially for small atolls. The two neighboring atolls shown here have some unique features. What was a lagoon on Nukutavake (19°17′ S 138°48′ W, 6.2 km²) is now dry and completely covered by vegetation. Pinaki (3.54 km²) has a drying shallow lagoon still connected to the ocean via a single narrow spillway. The variation of morphology implies that each atoll may have a different equilibrium between ocean, lagoon, and land ecosystems.
Published Jul 1, 2001
This astronaut photograph depicts Apataki Atoll, an atoll in the Tuamotu Islands in the south Pacific. Atolls are ring-like coral islands that nearly or entirely enclose a lagoon. The atoll traces the perimeter of what was once the coastline of a volcanic island. In 1722, Dutch navigator Jakob Roggeveen became the first European to see the Apataki Atoll. It was later visited by Captain Cook in 1774.
Published Mar 6, 2006
This astronaut photo of Millennium Island shows emerald islets surrounding a turquoise lagoon dotted with coral.
Published Jul 13, 2009
Lakshadweep’s coral atolls glow iridescent blue-green in this natural-color scene from February 2012.
Published Apr 15, 2012
The Whitsunday Islands are a collection of some 74 islands sandwiched between the Australian mainland and the outer atolls of the Great Barrier Reef.
Published Jan 2, 2010
