Transcript Chapter 19 Section 1 Review Page 474

Chapter
19 Section
2 Review
Page 478
#’s 1-6
1. Describe the three main
sections of the
continental margins.
• The continental shelf is the
submerged part of the continent.
• The continental slope is the steep,
seaward edge of the shelf.
• The continental rise is a raise wedge
of sediment at the bottom of the
slope.
Continental Margin
2. Describe where the boundary
between the ocean crust and the
continental crust is located.
• The boundary is generally offshore at
the base of the continental slope.
Continental Slope
3. Explain how turbidity
currents are related to
submarine canyons.
• Submarine canyons may form where
large amounts of sediment tumble
down a slope as part of a turbidity
current.
Turbidity Currents
4. List four main features
of the deep-ocean
basins, and describe one
characteristic of each
feature.
• Trenches: very deep, formed by
subduction
• Abyssal plains: vast, flat areas more
than 4 km. deep and covered with a
fine sediment
4. (Continued)
• Mid-ocean ridges: form where
plates move apart and have a
narrow rift
• Seamounts: submerged
volcanoes that may rise above
the ocean to form volcanic
islands
Seafloor Features
5. Compare seamounts,
guyots, and atolls.
• A seamount is an underwater
volcanic mountain.
• Guyots and atolls form from islands.
When an island sinks and the top
erodes flat you get a guyot. Before
the island sinks completely an atoll
may form around the sinking volcano
in the shallow water.
Seafloor Features
Formation of an
Atoll
An atoll
6. Explain the difference
between the
meanings of the terms continental
margin, continental shelf, continental
slope, and continental rise.
• The continental margin is the name
for all parts combined;
• the continental shelf, continental
slope, and the continental rise.
Continental Margin
Image: Continental margin –
California coast
The
End?