It is an uninhabited, roughly circular atoll about in diameter, which corresponds to a total size ( including lagoon ) of.

The atoll has been occupied at various times by guano miners, would-be settlers or military personnel, mostly from Mexico, which formerly claimed it until international arbitration awarded it to France in 1931.

In 2005, Clipperton's ecosystem was extensively studied for four months by a scientific mission organized by Jean-Louis Étienne, which made a complete inventory of mineral, plant, and animal species found on the atoll, studied algae as deep as 100 m ( 330 ft ) below sea level, and examined the effects of pollution on the island.

There are about 30 separate reefs and atolls, twelve being wholly submerged or drying only during low tide, and 18 others with a total of about 51 islets and cays ( 18 alone on the atoll Lihou Reef ), some of which are vegetated.

Diego Garcia is the largest land mass in the Chagos Archipelago ( which includes Peros Banhos, the Salomon Islands, the Three Brothers, the Egmont Islands and the Great Chagos Bank ), being an atoll occupying approximately, of which is dry land.

Larger amounts of radioactive material were later isolated from coral debris of the atoll, which were delivered to the U. S. The separation of suspected new elements was carried out in the presence of a citric acid / ammonium buffer solution in a weakly acidic medium ( pH ≈ 3. 5 ), using ion exchange at elevated temperatures ; fewer than 200 atoms of einsteinium were recovered in the end.

The pre-20th century names Danger Reef, Caldew Reef, Maria Shoal and Crane Shoal refer to this atoll, which by then was entirely submerged at high tide.

The most populous atoll is Majuro, which also acts as the capital.

He bought a 12-island atoll, Tetiaroa, which he intended to make partly an environmental laboratory and partly a resort.

The largest island, Wake Island, is the center of activity on the atoll and is the location of Wake Island Airfield, which has a runway.

More modern definitions of atoll are those of McNeil ( 1954, p. 396 ) as ".. an annular reef enclosing a lagoon in which there are no promontories other than reefs and islets composed of reef detritus " and Fairbridge ( 1950, p. 341 ) "... in an exclusively morphological sense, ... a ring-shaped ribbon reef enclosing a lagoon.

* Lansdowne Bank, west of New Caledonia ( 21000 km² ), submerged, least depth 3. 7 m More sources however list as the largest atoll in the world in terms of land area Kiritimati, which is also a raised coral atoll ( 321. 37 km² land area ; according to other sources even 575 km² ), 160 km² main lagoon, 168 km² other lagoons ( according to other sources 319 km² total lagoon size ).

The land area of the atoll is 18. 05 km², of which the main island occupies 16. 8 km².

The main island of Aitutaki occupies the northern part of the atoll, which is roughly triangular in shape.

They found artifacts of uncertain origin on the weather-ravaged atoll, including bronze bearings which may have belonged to Earhart's aircraft and a zipper pull which might have come from her flight suit.

In the first season episode " Big Man on Little Stick " as the Professor is helping surfer Duke Williams with provisions before his trip back to Hawaii he mentions the location as, which would put it very close to Clipperton Island, an uninhabited atoll owned by France.

Amongst the 15 or so islands of the atoll, Palmerston Island is the only one which is inhabited.

or Marcus Island is an isolated Japanese coral atoll in the northwestern Pacific Ocean, located some SE of former Tokyo City and east of the closest Japanese island, South Iwo Jima of the Ogasawara Islands, and nearly on a straight line between mainland Tokyo and US ' Wake Island, which is east southeast.

The southernmost and largest island in the atoll is named Kwajalein Island, which English-speaking residents often call by the shortened name, Kwaj ().

Nuclear refugees from the atolls irradiated by the American tests were also moved to Ebeye, and in 1964, when the United States initiated its Anti-ballistic missile testing program with the Nike-Zeus program in Kwajalein Atoll, authorities moved also the remaining Marshall Islanders who lived scattered on their land throughout the atoll to the small shantytown of Ebeye which had been erected with plywood housing by American contractors.

Unclear and insufficient in the opinion of these landowners, the original lease arrangements for Kwajalein Atoll with the U. S. were finally negotiated only after the landowners and their supporters demonstrated in the early 1980s with a peaceful protest called " Operation Homecoming ," in which Islanders re-inhabited their land at Kwajalein, Roi-Namur, and other restricted sites in the atoll.

Baker Island () is an uninhabited atoll located just north of the equator in the central Pacific Ocean about southwest of Honolulu.

The atoll has long been a maritime hazard and is the site of numerous shipwrecks.

Clipperton Island ( or ) is an uninhabited coral atoll in the eastern Pacific Ocean, southwest of Mexico and west of Costa Rica, at.

The ring-shaped atoll completely encloses a stagnant freshwater lagoon, and is.

North Keeling Island is an atoll consisting of just one C-shaped island, a nearly closed atoll ring with a small opening into the lagoon, about wide, on the east side.

South Keeling Islands is an atoll consisting of 24 individual islets forming an incomplete atoll ring, with a total land area of.

Diego Garcia is a tropical, footprint-shaped coral atoll located south of the equator in the central Indian Ocean.

The atoll is approximately east of the coast of Africa ( at Tanzania ), south-southeast of the southern tip of India ( at Kanyakumari ) and west-northwest of the west coast of Australia ( at Cape Range National Park, Western Australia ).

The total area of the atoll is.

The coral reef surrounding the seaward side of the atoll is generally broad, flat, and shallow at about below mean sea level in most locations and varying from 300 to 650 feet ( 100 to 200 m ) in width.

Diego Garcia is the above-water rim of a coral atoll composed of Holocene coral rubble and sand to the depth of about 36 metres ( 120 ft ), overlaying Pleistocene limestone deposited at the then-sea level on top of a seamount rising approximately 1, 800 metres ( 6, 000 ft ) from the floor of the Indian Ocean.

One of these is centered on the northwest point of the atoll, another is found near the Point Marianne Cemetery on the southeast end of the airfield.

Because of the protections provided the species on this atoll, and the isolation of the east rim of the atoll, the species is recorded in greater densities there than anywhere else in its range ( 339 crabs / ha ).

Wake Island is a volcanic island that has become an atoll

An atoll is an island formed from a coral reef that has grown on an eroded and submerged volcanic island.

Johnston Atoll is a atoll in the North Pacific Ocean about west of Hawaii.

Since the base was closed, the atoll is likely to have been visited by sailing vessels crossing the Pacific, as the deserted atoll has a strong lure due to the activities once performed there.

On Diego Garcia, the main plantations were located at East Point, the main settlement on the eastern rim of the atoll ; Minni Minni, north of East Point ; and Pointe Marianne, on the western rim, all located on the lagoon side of the atoll rim.

* 1952 – Operation Ivy – The United States successfully detonates the first large hydrogen bomb, codenamed " Mike " for megaton, in the Eniwetok atoll, located in the Marshall Islands in the central Pacific Ocean.

The atoll is, and it is located in the equatorial Northern Pacific Ocean.

Wake Island (; also known as Wake Atoll ) is a coral atoll having a coastline of in the North Pacific Ocean, located about two-thirds of the way between Honolulu, to the east and Guam, to the west.

* Ebadon (, ) is located at the westernmost tip of the atoll.

It is the second westernmost atoll of the Ralik Chain, and is located west from Bikini Atoll.

The atoll is located at and belongs to the Aldabra Group, one of the island groups of the Outer Islands of the Seychelles, which includes the island of Assumption and the atolls of Astove and Cosmoledo.

It is an atoll located at.

Abaiang, also spelled Apaiang, sometimes called Apiaia, and formerly named Charlotte Island, Matthews or Six Isles, is a coral atoll of Kiribati, located in the west-central Pacific Ocean.

The commune of Bora-Bora is made up of the island of Bora Bora proper with its surrounding islets emerging from the coral reef, 29. 3 km² ( 11. 3 sq mi ) in total, and of the atoll of Tupai (), located north of Bora Bora.

The commune of Bora-Bora is made up of the island of Bora Bora proper with its surrounding islets emerging from the coral reef, 29. 3 km² ( 11. 3 sq mi ) in total, and of the atoll of Tupai (), located north of Bora Bora.

Woleai, also known as Oleai, is a coral atoll of twenty-two islands in the eastern Caroline Islands in the Pacific Ocean, and forms a legislative district in Yap State in the Federated States of Micronesia and is located approximately west-northwest of Ifalik and northeast of Eauripik.

Some of the ancient kings of Maldives traced their ancestry to certain families of Devvadu island, located at the centre of this large atoll.

Thoddu Atoll is a solitary round-shaped atoll located in deep waters at the western entrance of the Kardiva Channel.

It is located north of the atoll of Aur.

Butaritari ( previously known as Makin, Pitt Island, Taritari Island, or Touching Island ) is an atoll located in the Pacific Ocean island nation of Kiribati.

It is an atoll located in the South Pacific Ocean roughly halfway between Hawaii and Fiji at.

Île Yeye, located at the northeastern corner of the atoll, is the island of the Chagos that is closest to the Maldives.