Fringing reefs becoming atolls#

Image courtesy of NASA., under PD

This astronaut photo captures the evolutionary process of fringing reefs gradually becoming atolls. As with the Hawaiian Islands, these volcanic hot spot islands become progressively older to the northwest.

As these islands move away from their magma sources they erode and subside. The two large islands, Raiatea and Tahaa, share a single fringing reef. The next island to the northwest, Bora-Bora, consists of a highly eroded volcanic remnant with fringing reef.

The last island, Tupai, signifies the destiny of these islands; the fringing reef has become an atoll with the central island below sea level.