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
Bay mouth bar	Littoral drift	Spit
Beach drift	Marsh	Tides
Groynes (groins)	Protogradation	Tombolo
Headlands	Retrogradation
Hooked spit	Salt flats

 

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, 2^nd 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