A semicircular reef that is most closely associated with degradation of volcanic islands is called a(n)
A) fringing reef.
B) barrier reef.
C) atoll.
D) lagoon.
E) coral reef.

Question

Quizplus · Accepted Answer

An atoll is a semicircular reef that forms when a volcanic island sinks and erodes away, leaving a ring of coral reef around a central lagoon. This is typically caused by geological subsidence, and is a common occurrence in the Pacific Ocean, particularly around the Hawaiian Islands. Fringing reefs and barrier reefs, by contrast, are typically associated with stable continental shelves, and may form around islands, peninsulas, or along the edge of a coast. A lagoon is a shallow, enclosed body of water that may form within a reef system, often behind a barrier reef.

A Semicircular Reef That Is Most Closely Associated with Degradation