Types of Reefs
Fringing Reef
Barrier Reef
Atoll
Continental islands are simply
unsubmerged parts of the
continental shelf which are
entirely surrounded by water.
Barrier Reef
Islands which rise to the surface
from the floors of the ocean basins
are called oceanic islands. These
islands are volcanic. Lava accumulates
to enormous thickness until it finally
protrudes above the ocean surface.
Atoll
Atoll is generally found far from land.
It is a reef in the form of a circle, crescent, or
horseshoe which encloses a shallow lagoon
of clear and placid water. Sometimes the
lagoon is completely cut off from the sea;
but usually there are channels which allow
ships to enter the lagoon. These lagoons
make excellent harbors in storms,
but they must be navigated carefully,
for there are sometimes coral formations,
called pinnacles, just beneath the surface
of water. It looks like a chain of islands.
Atolls may rise up to 20 feet above the
surface of the water. In time, they
develop tropical plant and animal life
and become habitable islands.
Pinegreenwoods Montessori
Montessori Geography
