Oceania and Antarctica


What is an atoll

In addition to reefs, coral can also form atolls. Atolls are formed when a volcano, around which coral often grows, erodes away, leaving a circular wall of coral with a lagoon at the center.


This is a web preview of the "The Handy Geography Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App