 What
lies at the bottom of the ocean?
Exploring the Ocean
S6E3.c – Describe the
composition, location, and
subsurface topography of the
world’s oceans.
S6CS3 – use computation to
analyze scientific data.
Locate the Oceans
On your map handout, label the 5 major oceans.
What do you know about the oceans?
1. Which ocean is the deepest?
a. Atlantic b. Pacific
c. Indian
2. Which ocean has the deepest point on the
ocean floor?
a. Atlantic b. Pacific
c. Indian
The Challenger Deep is the deepest point at 35,802 feet
deep. It is located off the coast of Guam in the Marianas
3. Where is the world’s longest mountain range?
a. Atlantic b. Pacific c. Indian
4. What is the smallest ocean?
a. Atlantic b. Southern c. Arctic
Group discussion
Why are the oceans so difficult to study?
What kinds of technology would help
scientists learn more about the deepocean floor?
Mapping the Ocean Floor
Seeing by Sonar
Sound Navigation and Ranging
Technology is based on the echoranging behavior of bats.
Purpose: Use to determine the
ocean’s depth by sending sound
pulses from a ship down into the
Sound bounces off of the ocean floor
and travels back to the ship.
Time it takes for the signal to bounce
back, determines the distances.
1970 Scientists starting using satellites.
images are used to study
ocean currents.
Images used to measure
slight changes in the
height of the ocean’s
Exploring the Ocean with Underwater
Piloted Vessels:
Robotic Vessels:
Alvin and Deep Flight
Two research vessels that
can reach some of the
deepest parts of the ocean.
JASON II and Medea
Jason explores the ocean
floor, Medea is attached
with a tether.
 Science
What lies at the bottom of the ocean and
A: a nervous wreck
Revealing the Ocean Floor
 Using
your textbook, pages 384 and 385,
complete the ocean floor worksheet.
 Label the pictures.
1. Continental shelf
c. gently sloping area bordering a continent
2. Continental slope
e. a steady incline starting at the end of a continental shelf
3. Seamount
b. mountain whose peak does not break through the surface of the
4. Abyssal plain
f. broad flat area covered with thick layers of mud and silt
5. Volcanic island
d. a volcano on the ocean floor that creates a mountain big enough
to break the ocean surface.
6. Mid-ocean ridge
a. consists of many peaks along both side of a central valley.
7. Trench
g. a long, narrow, and deep depression with steep sides on the
ocean floor.
Continental slope
Volcanic island
Continental rise
Continental slope
Abyssal plain
mid-ocean ridge
Rift valley
With sonar, what happens to sound pulses from
a ship after they hit the ocean floor?
A: they bounce back to the ship
2. What can scientist conclude the longer it takes
sound to return to a ship?
A: the deeper the ocean floor is in that spot
3. What are 4 ways that scientist study the ocean
A: sonar, piloted vessels, robotic vessels and
4. What is a guyot?
A: flat-top seamount
5. Where is the mid-ocean ridge located?
A: Atlantic ocean

Exploring the ocean