coral reefs?

Question

What are the three types of coral reefs?

Answer 1

the fringing reef, the barrier reef, and the atoll.

Answer 2

There are four not three types

Coral reefs are divided into four main types: fringing reef, platform reefs, barrier reefs and atolls.

Fringing reef Fringing reefs are relatively young. They can develop in shallow waters along the coast of tropical islands or continents. The corals grow upwards to sea level or just below and outwards towards the open ocean. Fringing reefs are generally narrow platforms a short distance from shore and don't contain a substantial lagoon.

Platform reefs usually lie in sheltered seas and quite far offshore. They are flat-topped with small and very shallow lagoons.

Barrier reef
A coral reef growing parallel to the coastline and separated from it by a lagoon is called a barrier reef. The lagoon may develop between the fringing reef and the land. As the reef continues to grow further and further offshore it eventually reaches the edge of the continental shelf. Barrier reefs can also originate offshore if the depth of the seabed out there is shallow enough to allow corals to grow.

The most famous barrier reef is the Great Barrier Reef in Australia. It stretches over 2300 km and covers over 200'000 km2. It lies between 24 and 240 km from the main continent.

Atoll
Atolls are rings of reef, often encircling an island (sand and coral rubble). They typically have a shallow, sandy, sheltered lagoon in the middle. Access to the open sea beyond is through a number of channels. These provide fresh and colder water for the lagoons. Corals atolls are on the top of submarine mountains. These mountains are remnants of volcanos. Once there were fringing reefs around the volcano. As it slowly submerged the corals continued to grow up to the surface of the water. What remained after the volcano became invisible is a ring of coral reefs surrounded by deep ocean.

However some atolls were probably formed by rising sea levels rather by the sinking of islands. Other theories suggest that corals colonized eroded limestone formations, so called karstic saucers.

Answer 3

Coral reefs are generally found in clear, tropical oceans. Coral reefs form in waters from the surface to about 150 feet deep because they need sunlight to survive. The three types of reefs include fringing reefs, barrier reefs, and atolls. Fringing reefs occur along shorelines of continents and islands and are commonly found in Hawaii and the Caribbean. Barrier reefs are found farther offshore than fringing reefs, they occur most often in the Indo-Pacific and Caribbean. Atolls are a series of low coral islands surrounding a central lagoon, frequently found in the Indo-Pacific. The largest reef in the world, the Great Barrier Reef in Australia is longer than 1200 miles. That’s longer than the distance between Seattle, WA and Los Angeles, CA!