A reef than surrounds a volcanic island is an : Atoll
Atoll usually takes shapes in a form of ring that surround the areas of volcanic island that consist of corals. It usually only exist in warm waters, so volcanic islands will provide perfect environment for the corals
hope this helps<span />
Answer:
True.
It is true that Europe and Asia are on the same land mass.
- <em>Land mass is a large body of land.</em>
<em>I hope this helped at all, sorry if it's incorrect.</em>
Answer:
In the upper reaches (also known as the source) the gradient is at its steepest because of vertical erosion. This changes further downstream as lateral erosion (side to side) from the river and deposition start to replace vertical erosion as the dominant process. Finally, the river really flattens out as it approaches the mouth as deposition become dominant.