Transcript The Ocean Floor

Bellringer
Pretend you have walked off the edge of North America
and into the depths of the Atlantic Ocean. As you walk
along the ocean floor toward Europe, what do you see?
Draw the ocean floor as you imagined it.
Illustrate your answer in your science notebook.
Ms. Ginnever, Student Teacher
7th Science
Studying the Ocean Floor
 Satellite
 1978 scientists launched the satellite Seasat
 Focused on the ocean, sending images back to Earth to
measure direction and speed of ocean currents.
 Geosat
 Used to be a top-secret military satellite
 Measures changed in ocean surface and underwater
features, such as mountains and trenches.
 Sonar
 Sound navigation by ranging
The longer it takes for
the sound to bounce off
the ocean floor and
return to the ship, the
deeper the floor is in
that spot.
Satellite image
Revealing the Ocean Floor
https://www.youtube.com/watch?v=K8blL9Ki2mQ
Continental Margin
Continental Margin
 Continental Shelf
 Begins at the shoreline
and slopes towards the
open ocean
 It continues until the
ocean floor slopes more
steeply downward
 The depth can reach 200
meters
 Continental Slope
 Begins at the edge of the
continental shelf and
continues down to the
flattest part of the ocean
floor
 The depth ranges from
200 meters to 4,000
meters
Continental Margin
 Continental Rise
 Is the base of the continental slope and is made up of
large piles of sediment
 It’s the boundary between the continental margin
and the deep-ocean basin
Deep Ocean Basin
Deep Ocean Basin
 Abyssal Plain
 Depth of 4,000 meters
 Broad flat part of the
deep-ocean basin
 Covered by mud and
remains of marine
organisms
 Mid-Ocean Ridges
 Mountain chains that
form where tectonic
plates pull apart
 Pulling action creates
cracks called rift zones.
 As rifts form magma
rises to fill in the cracks
which causes the rifts to
expand and rise to
create the ridges
Deep Ocean Basin
 Rift Valley
 The area between the
ridges in the rift zone
 Ocean Trenches
 Huge cracks in the deep
ocean basin
 Ocean trenches are
formed when the
oceanic plate is pushed
below the continental
plate or another oceanic
plate
 Seamounts
 Individual mountains of
volcanic material
 Formed when magma
pushes it’s way between
tectonic plates
 If a seamount builds up
above sea level it
becomes a volcanic
island
Exploring with Underwater Vessels
 Piloted Vessels
 Alvin
 Deepworker
https://www.youtube.com/watch?v=AU4_Y
2o45I4