 Fringing Reefs |
 Barrier Reefs |
 Atolls |
Types of reef:
As coral reefs are built, they go through different stages of growth. Throughout development, coral reefs characteristically sink into the water. Each of the following three stages describes a step the reef goes through while it sinks.
There are three types of corals: fringing reefs, barrier reefs, and atolls. Proposed by Darwin while aboard the Beagle and proven by Henry S. Ladd and Joshua I. Tracy of USGS when they hit volcanic rock during drilling, many corals are made on volcanic cones that are sinking while coral growth remains steady. Corals grow around an island and as the island sinks, the corals continue to grow upward. Fringing reefs are located in shallow water border and grow parallel the coast. The fringing reef is the 1st stage of coral growth, being close to the island.
Barrier reefs are like fringing reefs because barrier reefs also grow parallel to the coast. The difference between barrier and fringing reefs is that barrier reefs grow farther out from land. Barrier reefs are the 2nd stage in coral reef development where the island has begun to sink. A well-known example of a barrier reef is the Great Barrier Reef located in northeast Australia. The Great Barrier Reef is 2000 km long, 145 km long, and 120 m high.
Atolls are circles of corals with a lagoon in the center. This is the final stage in coral reef development. In this stage, island has been completely been submersed in water. Its submersion explains why there is a lagoon in the center. Hundreds of atolls are speckled across the South Pacific. Now, you can clearly imagine how the reefs skip through the 3 stages as a result of the reef’s sinking movement from fringing reefs to barrier reefs to atolls.
