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A reef has 2 main characteristics

1. Ridge of rock or sand

2. At or near the surface of water

Examples of reef landforms:

Great Barrier Reef near Australia
Recife, Brazil

What is a Reef?

The true definition of a reef is a ridge of a rock or any other type of land that extends some distance just under the the surface of the water. 

The type of reef that we are going to focus on and what most people know about are coral reefs, which are actually alive.  A coral reef is a lot of calcium carbonate that is also made up of living creatures.  So, when you are thinking of a coral reef, you can think about it actually being alive!

How are Reefs Formed?

A regular reef is formed a few different ways.  A common way is flooding of a land from the ocean.  The ocean may now contain some land that is cliff like which is called a reef.  A coral reef is created when when a small amount of dead coral dies and turns into calcium carbonate.  New coral is constantly being made and attaches to the dead reef.  This process is a long cycle. In clean and protected waters, reefs will grow large and beautiful.

Famous Reefs

One of the famous reefs of the world are the Great Barrier Reef of Australia.  It extends about 1300 miles and is filled with beauty.  Belize and the Cayman Islands also carry famous reefs.

Reef Definition

A reef is a a ridge of rocks and/or sand, often of with coral debris, at or near the surface of the water.