LAB 9: COASTAL ENVIRONMENTS
Note: Please refer to the GETTING STARTEDmodule to learn how to maneuver through, and how to answer the lab questions, in the Google Earth () component.
KEY TERMS
You should know and understand the following terms:
|
Barrier island |
Lagoon |
Sea stack |
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Bay mouth bar |
Littoral drift |
Spit |
|
Beach drift |
Marsh |
Tides |
|
Groynes (groins) |
Protogradation |
Tombolo |
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Headlands |
Retrogradation |
|
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Hooked spit |
Salt flats |
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LAB LEARNING OBJECTIVES
After successfully completing this module, you should be able to the following tasks:
· Identify erosional processes and features created by coastal waters
· Identify depositional processes and features created by coastal waters
· Examine the processes which create coastal landforms
· Interpret topographic maps
· Calculate elevation from topographic maps
INTRODUCTION
In this module you learn about some fundamental concepts of coastal environments. Topics covered include coastal erosion and deposition processes and features, the tides, and jetties. The module starts with four opening topics, or vignettes, which are found in the accompanying Google Earth file. These vignettes introduce basic concepts and tools on which geographers rely. Some of the vignettes have animations, videos, or short articles that will provide another perspective or visual explanation for the topic at hand. After reading the vignette and associated links, answer the following questions. Please note that some links may take a while to upload based on your internet speed.
Expand the INTRODUCTION folder and then double-click Topic 1.
Read Topic 1: Introduction.
Question 1: Which of the following is not a reason people live near or on the coast?
A. Transportation
B. Aesthetics
C. Access to fresh water
D. Access to ocean resources
Read Topic 2: Tides
Question 2: What is the height of a normal high tide in the Gulf of Mexico?
A. 1 meter
B. 5 meters
C. 2 meters
D. 0.5 meters
Read Topic 3: Human Interaction
Question 3: which of the following is not a structural methods humans use to protect a shoreline.
A. Seawalls
B. Groins
C. Jetties
D. vegetation
Read Topic 4: Coastal Landforms
Question 4: In the Lake Ellesmere reading, the Banks Peninsula headlands are not eroded as intensely as other headlands. Why?
A. Efficient reflection of wave energy
B. Seawalls absorb wave energy
C. Headlands are made of hard material
D. Offshore sand bars slow waves down
Collapse and close INTRODUCTION
GLOBAL PERSPECTIVE
Double-click and select GLOBAL PERSPECTIVE.
This map shows the location of major coastal cities located throughout the world. At present, coastal cities are increasing in population numbers, population density, and spatial extent, with many coastal areas becoming more urbanized.
For Questions 5 to 8, type the information provided into the Search tab in Google Earth and press Enter. When you arrive at your destination, find the information to fill in the blanks below. You might have to zoom out to see the label for the body of water. Verify that the Water Bodies line item is selected (Figure 1).
Question 5: Buenos Aires, Argentina
Body of water:
A. Pacific Ocean
B. Gulf stream
C. Rio de La Plata
D. Amazon River
Question 6: Los Angeles, CA
Body of water:
A. Pacific Ocean
B. Gulf stream
C. Rio de La Plata
D. Amazon River
Question 7: 31 13 49 N, 121 28 25 E
Body of water:
A. Yellow Sea
B. East China Sea
C. Taiwan Strait
D. Philippine Sea
Question 8: 19 01 41N 72 51 22E
Body of water:
A. Bay of Bengal
B. Arabian Sea
C. South Sea
D. Sri Lankan Sea
Collapse and close GLOBE PERSPECTIVE
EROSIONAL FEATURES
Expand EROSIONAL FEATURES. Double‑click and select
.
Question 9: What is the name of the feature where letter A is located?
A. Spit
B. Headland
C. Beach
D. Lagoon
Double‑click and select Newport North, OR.
Question 10: Use the contour lines to estimate the elevation of the highest point of this feature (near the radio symbol).
A. 80 ft
B. 160 ft
C. 240 ft
D. 360 ft
Question 11: What other land uses are not found on this feature?
A. Light house
B. Quarry
C. Houses
D. Golf course
Double-click and select Agate Beach. At the bottom of the screen, click the 1994 date (
) to activate the historical imagery tool. Examine the beach in 1994.
Double-click and select
.
Question 12: Using the ruler tool to measure, estimate the distance (in meters) from to the water?
A. 15 meters
B. 50 meters
C. 100 meters
D. 150 meters
Advance the time slider to 2005 and examine the beach.
Question 13: Assuming the tide in the image is the same as 1994, estimate the distance (in meters) from to the water?
A. 20 meters
B. 80 meters
C. 200 meters
D. 260 meters
Question 14: What is the average change in the width of the beach from 1994-2005? (Hint: Calculate the difference in distance divided by the number of years)
A. (20m – 15m) ÷ 11 years = 0.45m/year
B. (80m – 50m) ÷ 11 years = 2.73m/year
C. (200m – 100m) ÷ 11 years = 9.09m/year
D. (260m – 150m) ÷ 11 years = 10m/year
Question 15: Assuming both images were captured at low tide, is this part of Agate beach experiencing progradation (expansion) or retrogradation (contraction)?
A. Progradation
B. Retrogradation
Double-click and select South Beach.
Question 16: Identify a feature that mitigates the erosional power of waves.
A. Seawall
B. Breakwater
C. Jetties
D. Bridge
Question 17: In which general direction is littoral drift moving?
A. North
B. East
C. South
D. West
Double-click and select Jump‑off Joe.
You will see a section of Nye Beach.
Double‑click the Newport North, OR map again to verify the location of the Jump‑off Joe symbol. Use the Adjust Opacity tool
to compare the aerial photograph to the topographic map. As you can see, there is not much at this location other than a sandy beach.
Double‑click Jump‑off Joe again. To read more about Jump-off Joe, type the following URL into your browser to go to the USGS web site: http://walrus.wr.usgs.gov/pubinfo/jump.html
Question 18: What coastal feature used to be at the Jump‑off Joe symbol?
A. Headlands
B. Sea walls
C. Sea stack
D. Sand dune
Collapse and close EROSIONAL FEATURES
DEPOSITIONAL FEATURES
Double-click DEPOSITIONAL FEATURES.
This is a typical view of a landscape in which transportation and subsequent deposition of material is common along the southeastern coast of the US.
Double-click and select Hampstead, NC.
The map shows a series of islands off the coast of North Carolina.
Question 19: What coastal feature are these islands?
A. Barrier islands
B. Mud flats
C. Rock islands
D. Salt marshes
Several topographic features can be found within this coastal feature. If you need help understanding the topographic symbols, type the following URL into your browser to go to the USGS web site:
http://pubs.usgs.gov/gip/TopographicMapSymbols/topomapsymbols.pdf
Question 20: What feature is represented by the brown dots?
A. Gravel
B. Sand or mud
C. Dry lake
D. Tailing pond
Question 21: What feature is represented by the black dots?
A. Gravel
B. Foreshore flat
C. Pebbles
D. Mud
Question 22: What is represented by the blue clumps of vegetation?
A. Marsh
B. Submerged marsh
C. Wooded marsh
D. Land subject to inundation
Question 23: Estimate the elevation of the highest point on Figure Eight Island (Hint: Look to the bottom of the historic map to determine the contour interval).
A. 5ft
B. 10ft
C. 25ft
D. 35ft
Zoom in and examine the break between the two islands near the horizontal control named Wow, as seen in Figure 2.
Uncheck Hampstead, NC.
Question 24: What has happened to the two barrier islands?
A. Tectonic activity has closed the gap
B. Sand has filled the gap between the two islands
C. Erosion has filled in the gap
D. The gap still exists
Double-click and select the
symbol.
Question 25: What is this coastal feature called?
A. Curl
B. Spit
C. Hooked spit
D. Lagoon
Question 26: Based on the shape of , what is the prevailing direction of the waves?
A. NE
B. NW
C. SE
D. SW
Collapse and close DEPOSITIONAL FEATURES
LITTORAL DRIFT
Expand LITTORAL DRIFT, click Littoral Drift Video, and then click Play.
Dr. Mark W. Patterson demonstrates the concept of littoral drift.
Click Littoral Drift Animation.
Given what the video and animation demonstrated about littoral drift, answer the following questions.
Expand the Littoral Drift Examples folder.
Double‑click and select Littoral Drift #1.
Question 27: Which general direction is the littoral drift moving?
A. NW
B. SE
C. SW
D. NE
Double‑click and select Littoral Drift #2.
Question 28: Which general direction is the littoral drift moving?
A. North
B. West
C. East
D. South
Double‑click and select Littoral Drift #3.
Question 29: Which direction is the littoral drift moving?
A. North
B. West
C. East
D. South
Double‑click and select Littoral Drift #4.
Question 30: Which direction is the littoral drift moving? ___________________
A. North
B. West
C. East
D. South
Question 31: Based on the animation, describe the impact that groynes have on littoral drift.
A. Groynes stop littoral drift
B. Groynes slow littoral drift along the entire beach
C. Groynes slow littoral drift along its wave side
D. Groynes slow littoral drift along its lee side
Question 32: Would a conservationist want groynes used? Why or why not?
A. Yes, because they stop erosion
B. No, because they interrupt a natural coastal process
C. Yes, because they keep the beach in place
D. No, because they are an eyesore
Question 33: Would a homeowner whose house is on the beach want groynes used? Why or why not?
A. Yes, because they stop unwanted deposition
B. No, because they interrupt a natural coastal process
C. Yes, because they keep the beach in place
D. No, because they are an eyesore
References:
Alan Arbogast. 2011. Discovering Physical Geography, 2nd edition. John Wiley and Sons, Inc.
NOAA. 2011. http://oceanservice.noaa.gov/facts/population.html [date accessed 3/16/11]
Sources
Page 2. Hong Kong, from Victoria Peak. (Nancy Hoalst‑Pullen)
Page 3. Photo: Tidal Marsh (Mark W. Patterson).
Page 4. Photo: Groynes (groins) and shoreline processes (Figure 19.39 in Arbogast 2011)
Page 5. Photo: South Island, New Zealand (NASA). http://disc.sci.gsfc.nasa.gov/geomorphology/GEO_6/geo_images_C-10/PlateC-10.gif
Page 6. Photo: Coastal Erosion, Washington, USA (USGS). http://coastal.er.usgs.gov/cgi-bin/response.pl?site=wo&loc=24
