Ocean Topography and Composition
S6E3. Students will recognize the significant role of water in earth processes.
c. Describe the composition, location, and subsurface topography of the world’s oceans.
Ocean Feature
(A) Continental
Shelf
(Plateau)
Continental Slope
Definition
A gently sloping, shallow area of the ocean floor that extends outward from the edge of the
continent.
Can be compared to a plateau
A steep incline of the ocean floor leading down from the edge of the continental shelf.
(Cliff)
(B) Abyssal Plain
Can be compared to a cliff or slope
A smooth, nearly flat region of deep ocean floor.
(The Plains)
(C) Oceanic
Trench
Can be compared the plains
A deep, steep-sided canyon in the ocean floor.
Can be compared to a canyon or valley
(Canyon or Valley)
(D) Mid-Ocean
Ridge
(Mountain Range)
(F) Seamount
An undersea mountain chain where new ocean floor is produced.
Can be compared to a mountain range
Mountains that do not break the ocean’s surface. They are completely underwater.
(Mountain)
(E) Volcanic Island
Can be compared to a mountain
Mountains that break the ocean’s surface.
(Volcano)
Can be compared to volcano
Salinity: Two reasons why salinity of the ocean water could INCREASE:
1. Higher salinity is due to evaporation because water is changing into water vapor leaving salt behind
2. Higher salinity exists as surface water freezes into ice, salt is left behind.
Salinity: Two reasons why salinity of the ocean water could DECREASE
1. Lower salinity is found at the ocean’s surface because freshwater is added by rain, snow, and melting ice.
2. Lower salinity is found at the mouths of large rivers as they empty freshwater into oceans.