Transcript The Ocean Floor Features of the Ocean Floor Continental Shelf  Zone of shallow water where the ocean covers the end of the.

The Ocean Floor
Features of the Ocean Floor
Continental Shelf
 Zone of shallow water
where the ocean covers
the end of the continent.
 Shallow slope
 Where most ocean life is
found. Why?
 Answer: Photic zone is
the first 100 feet of water
and allows sunlight to
penetrate the water.
Continental Slope
 Continental slope is a
very steep slope off the
continental shelf.
 Here, the ocean becomes
very deep.
 Submarine canyons are
carved out by underwater
landslides called
turbidity currents.
Continental Rise
 Sediments from the
submarine canyons are
deposited further out in
the ocean.
 These sediments form
the continental rise.
 It is here that the
continental crust ends
and oceanic crust begins.
Abyssal Plain
• A large, flat, almost level
area of the deep-ocean
basin
 Abyssal plains cover
about half of the deepocean basins and are the
flattest regions on Earth.
 Layers of fine sediment
cover the abyssal plains.
Mid-Ocean Ridge
 Formed by divergent
plate boundary.
 Magma rises as plates
pushed apart.
 Forms underwater
mountain range of
volcanoes.
 These ridges can cause
sea level to rise and fall
drastically.
Guyots and Seamounts
 Guyot: A flat-topped
underwater mountain.
Formerly an island that
was eroded and sank into
the ocean.
 Seamounts: Pointedtopped underwater
mountain ranges that
were likely volcanic.
 Hawaii will become
seamounts and guyots.
Trenches
 Deepest point in the
ocean.
 Have the most pressure.
 Formed from convergent
boundaries where one
plate dives beneath
another (Subduction
zone).
 Often form Island Arcs
like Japan or Philippines.
Ocean Floor Sediments
Sediments
 Clastics: Sand, silt, mud, and clay found on
continental shelf make up the thickest sediments.
 Biogenic Sediments: Calcium carbonate and
Silica from organisms like forams and diatoms leave
oozes on the ocean floor that form Chert (Silica from
diatoms) and Chalk (Calcite from forams). Also
limestone (calcite).
 Chemical Sediments: Nodules of manganese,
copper, iron, and nickel can form and be found
scattered on the ocean floor.