Geog 106LRS - Prof. Fischer
Chapter 13b
Checkpoint 13.17
At which location on the following diagram would
the waves begin to break farthest from the beach?
Waves break when the water is shallow.
Therefore waves would break farthest from the
beach in c.
Name ____Answer key_________
There will be some erosion to the headlands, but
it will be only a few meters since the headlands
appear to be rock. Streams coming down the
canyon (below the bridge) may deposit sediment
in the sheltered bay, beginning to fill it in.
Checkpoint 13.22
Examine the section of coastline in the following
image (full frame below) taken at Santa Barbara,
California, about a mile from my house. Storms erode
sand from the cliff and carry it along the coast. In
what direction does the sand travel along the beach?
a) Right to Left (north) b) Left to Right (south)
Checkpoint 13.18
Standing on a beach, you observe a red ball floating
about 15 meters offshore. You notice that some welldefined waves are approaching the shore and are just
about to reach the ball. The waves are not breaking
until they are 5 meters from the beach. Where will the
ball be when the last wave reaches the beach?
a) Closer to shore
b) At about the same position
c) Farther offshore
The actual water in a wave moves in a circular
path unless the wave begins to break.
Checkpoint 13.21
Examine the following image (full frame below),
which shows a section of the California coastline near
Big Sur.
Checkpoint 13.23
Use the following terms to create a concept map that
illustrates how sand is transferred among the
components of the shoreline.
waves
wind continent dunes
beach
rivers
sand bar
longshore current
Good student responses will show multiple inner
connections and correctly label connecting
terms. Poor student responses will appear linear,
with multiple concepts that are incorrectly linked.
1. Describe the processes that would occur along this
section of coastline.
2. What do you think this scene will look like in 100
years?
Some sand will be deposited from long-shore
currents that move material parallel to the shore.
Checkpoint 13.24
Compare and contrast erosion, transport, and
deposition in stream systems and in coastal systems.
Identify at least 8 features.
Stream systems
Mix of grain sizes involved in all three processes
Erosion creates underwater channels.
Occurs at any range of elevation
All 3 processes driven by changing stream
currents
Both
Sediment source: continental interior
Sand deposited in bars
Both systems have similar erosion rates
Coastal systems
Immedidate sediment source: offshore sandbar
Erosion more pronounced in winter
Occurs at sea level
Erosion by wave action
All 3 processes driven by longshore current
Uniform grain sizes are involved at any given
point (e.g., mostly sand, or mostly gravel but
not both at the same time)
Checkpoint 13.25
Compare and contrast seawalls, breakwaters, and
groins.
Seawalls are closer to the shore (or at the shore)
while breakwaters are away from the shore. Both
are parallel to the shore and made of similar
materials. Seawalls stop erosion by withstanding
the wave impact, and breakwaters disrupt the
wave before it reaches the shoreline. Seawalls
can cause greater erosion on the flanks,
breakwaters cause deposition. Groins run
perpendicular to the beach and cause deposition
on the “upstream” side and erosion on the
“downstream” side, where the “stream” is the
longshore current.
Checkpoint 13.26
Review Figure 13.31 and explain why the shoreline
erosion/ deposition processes at the site of Cape
Hatteras required that the lighthouse be moved.
The lighthouse was originally protected by a
groin that caused deposition on one side and
erosion on the other. The groin was removed
after the move and now the beach is eroding
away from in front of the lighthouse. The
lighthouse should be safe for decades unless
coastal dynamics change significantly.
Checkpoint 13.27
In Chapter 11 we discussed the difference between
prevention and adjustment for flooding. Describe the
difference between prevention and adjustment
strategies for shoreline protection.
Prevention strategies seek to stop (or slow) the
natural processes that cause shoreline erosion
and/or deposition. Those include all the humanengineered armoring techniques. Adjustment
strategies focus on land management practices
that reduce risk by limiting development where
natural processes pose a significant threat.
Checkpoint 13.28
The U.S. Army Corps of Engineers is responsible for
spending money to protect the nation’s beaches that
are most susceptible to erosion. The Corps is funded
by the federal government. Should your tax money be
used to maintain wide beaches in places such as South
Carolina, Florida, or Texas? What are the
consequences of not funding these programs? Identify
arguments for and against continued federal funding
of artificial beach nourishment programs in states
with severe coastal erosion.
Good student responses will recognize that there
are multiple perspectives and multiple
stakeholders. The student will argue that any
one course of action will have consequences
that will affect others living in the area. Poor
student responses will simply select a
perspective and argue its merits without regard
to the consequences to others.
End of chapter Concept Map
Complete the following concept map to evaluate your understanding of the interactions between the Earth
system and oceans and coastlines. Label as many interactions as you can with information from this chapter.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
Tides due to gravitational attraction of moon, sun; sun supplies more heat to tropics
--Wind produces waves
Warm ocean waters evaporate
Plate tectonics created present ocean basins
Hot spring environment at oceanic ridges; Gulf Stream heats Europe to allow early blooming of plants (e.g.,
tulips)
Connection between Americas allowed migration of organisms
Shoreline altered by seawalls, etc.
--Early atmosphere from outgassing of Earth
Early oceans from out-gassing of early Earth; dissolved minerals give seawater its salt; more rapid sea floor
spreading increases sea level
Rivers cut submarine canyons on shelf, slope
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