Atoll. Atolls are oceanic reef formation, often having a characteristic ring-like shape surrounding a lagoon. Atolls are formed when coral reef grows around a volcanic island that later subsides into the ocean.
A coral atoll is a ring-shaped coral reef or island found in warm, tropical oceans. They are formed from the accumulation of coral skeletons on the rims of submerged volcanic islands over thousands of years. Atolls typically enclose a lagoon in their center.
The ends of an island are typically called "tips" or "points."
An atoll is formed from an island, but it isn't entirely an island. It's a coral reef that makes the different. The reef grows in a ring around the island and the island erodes, until little if any of it is above the surface of the water and the coral reef remains. Islands are any small body of land surrounded by water. Islands in the middle of the ocean are usually volcanic and islands in lakes and near continents are usually just areas of the continental shelf surrounding the continent with a higher elevation. To actually answer your question, the KEY difference is the reef.
The Japanese archipelago resembles a loop around the edge of the mainland.
An island chain is called an archipelago. It is a group or chain of islands clustered together in a body of water, such as the ocean.
Atolls
A ring shaped coral reef is called an Atoll.
Atoll.
atolls
ATOLL
A ring shaped coral island found for from land is called an atoll.
it is called ice ring island
atoll.
atoll
it's an island with a water court-yard
Atoll
annulus