Arlington High School
869 Massachusetts Ave.
Arlington, MA 02174
Why Are Places Located On Cape Cod That Way?
1. To study selected glacial features of Cape Cod on a satellite
2. To analyze where highways, airports, and people are located in relation to: geological features of glacial origin
1. Road map of Cape Cod
2. Satellite image of Cape Cod
3. Cape Cod topographic map
4. Shoe box or plastic box
6. Ice chips
7. Saran wrap
8. Tape or glue
9. File card
10. Pencil or pen
11. Coffee can to scoop sand
12. Selected map symbols
Moraine - A landform, usually composed largely of till, which is deposited at the margin of a glacier. Much of New England is covered by a thin veneer of moraine.
Outwash plains - Flat and gently-sloping plains underlain by meltwater stream deposits built beyond the margins of glaciers.
Recessional moraine - An end moraine which is deposited by a glacier that melts back from a terminal moraine. A good example is Cape Cod.
Terminal moraine - A deposit formed at the maximal extent of a valley or continental glacier. A good example is Long Island, Block Island, Marthas Vineyard, and Nantucket.
Essential Elements - III - Physical systems and IV - Human systems
Fundamental Theme - Human-Environment Interaction
9. The physical processes that shape the patterns of Earths surface.
12. The processes, patterns, and functions of human settlement.
Massachusetts Curriculum Framework:
Learning Standard 7 - Physical Spaces of the Earth
Learning Standard 9 - The Effects of Geography
The Lesson: Background
Cape Cod (41o 45 N, 70o 30 W) , jutting out into the Atlantic Ocean, is located on the eastern portion of Massachusetts. Unlike much of the New England coast that is made out of bedrock, Cape Cod consists entirely of sediment, mostly of sand and gravel.
The reason for this unique coastal feature lies in its origin. Over 12,000 ago the Earth was experiencing the last vestiges of the Ice Age. Cape Cod was formed by the glaciers as a land feature since the sea level had fallen. The ice in the glaciers had come from the oceans which lowered the sea level over 100 meters. During the Ice Age, the glaciers scraped the land, picked up sediment, and moved the sediment load toward the end of the glacier (See Figures 1 and 2). Once the sediment reached the end of the glacier, the ice would melt and drop the sediment. If this deposition happened at the farthest extent of the glacial advance, the mound of material deposited is called the terminal moraine. Later the glacier might recede back with increased melting. Then if the climate changed to cooler temperatures, the glacier would again start up the conveyor belt effect. This second mound of sediment build up behind the terminal moraine is called the recessional moraine. Under the ice, the glacier formed a topography named knob and kettle. The best way to describe such a landscape is hummocky (See Figure 3). The ups are the knobs and the downs are the kettles. Out in front of melting water, the rushing water creates a flat surface called the outwash plain. Sometimes blocks of ice would break off from the glacier and become embedded in the outwash plain. Later the ice blocks melted and left a depression that many times filled up with water called a kettle hole. Walden Pond in Concord, MA is the most famous of these ubiquitous kettle holes in Massachusetts. All of these features are in this lesson and can be seen both on the topographic map and satellite image.
Fig. 1. An ice sheet erodes by grinding and plucking of bedrock (left). In the region of wastage (right) the ice disappears through evaporation and melting, leaving its load of rock debris in the form of glacial till. From Arthur N. Strahler, A Geologist's View of Cape Cod, orig. Natural History Press, New York, 1966.
One 45 minute period
1. to understand how the glaciers formed Cape Cod out of sediment;
2. to define what a recessional moraine and outwash plain are;
3. to show how the highway system, airports, and human settlement were influenced by the physical landscape left by the glaciers.
1. Use the diagrams to explain the conveyor belt effect at the end of a glacier. See Figures 1 and 2 for visual explanations of this process.
2. Discuss how the glacial ice moves the sediment to the end of the glacier anddeposits the mixture.
3. Define this depositional structure left at the end of the melting glacier as a recessional moraine and the feature left in front of the moraine by the melting water as the outwash plain. See Figure 3 for this process.
4. Each student group receives a shoe box filled with sand, a pencil, a file card, ice chips, and a piece of Saran Wrap .
5. Using the diagrams showing the knob and kettle topography behind the recessional moraine and the flat surface of the outwash plain, shape the sand in your plastic box in a similar fashion. Divide the box into thirds the long way. Create the knob and kettle topography on the third to your left by poking the sand with a pencil or a finger so mounds and pits are developed.
On the two thirds of the box to your right, use the file card to smooth out the sand to form a flat surface to represent an outwash plain. Place some ice chips wrapped up in Saran wrap into the sand. Later the ice will melt. Some of the liquid water will pool in the Saran wrap to simulate kettle holes in the outwash plain. Place two ice chips in the outwash plain without Saran Wrap. These kettle holes will be depressions only without water in them.
6. Examine the satellite image (Figure 5 at end) with the aid of the Figure 4 and locate the Buzzards Bay Moraine that runs south from the Cape Cod Canal to Falmouth and the Sandwich Moraine that runs east from the Cape Cod Canal. Notice the many dark spots on the image that pock mark the Cape. These are kettle holes filled with water. Because of the different heat properties and reflectivity factors of water, water appears darker than land on infrared images.
Fig. 2 These two cartoons illustrate the formation of the glaciotectonic end moraines in contrast to conventional ideas of moraine formation. In the upper cartoon, the glacier is vigorously advancing over older deposits, piling up thrust sheets beyond the ice front represented by the bulldozer. In the lower cartoon, the conveyor belt represents an ice front that is stationary as ice advance is balanced by melting along the ice front. Debris carried forward by the ice is dumped at the ice front as it melts. Although part of the coastal end moraines may have been formed by the latter process, most of the moraines were formed by ice thrusting. Cartoons by Carol Parmenter of theU.S. Geological Survey.
Now that we know about how these glacial features formed and what they look like, we will look for these glacial landforms on a simplified topographic map of Cape Cod. We will only examine the mid-Cape that runs east and west from the Cape Cod Canal to Chatham.
7. Take the three segments of the contour outline map of Cape Cod, cut along dashed lines (do not cut along the shoreline), and tape the segments together. (Three segments printed at end of lesson.)
8. Trace in color along the contours using the following key:
0 meters Blue
20 meters Yellow
40 meters Brown
60 meters Green
80 meters Red
9. Use Figure 4 as a guide along with the Satellite Image of Cape Cod (Fig. 5) reprinted from Landsat false-. Now locate and label the Buzzards Bay Moraine which is the land within the 20 to 80 meter contours situated in a north south axis running from the Cape Cod Canal toward Falmouth. Use the road map to locate the towns. Locate and label the Sandwich Moraine which is the land within the 20 to 60 contours situated in an east west axis running from the Cape Cod Canal to about the town of Dennis. Locate and label the outwash plain which is located to the south and east of these moraines between the 0 and 20 meter contours.
Let's examine the location of human settlement in relation to these glacial features.
10. Cut out the airport symbols for Barnstable Airport, Otis Air Base, Cape Cod Airport, and Chatham Airport. Using the road map as a guide, paste or tape the symbols onto the contour map in their proper locations. Also draw in Route 6, the Mid Cape highway from the Cape Cod Canal to Chatham. (You will have to improve the printing and image when you reproduce the cutouts.)
11. What geologic feature are the airports located on?
Why do you think the builders and engineers chose these locations?
Where do you think the Martha's Vineyard and Nantucket airports are located? Explain your answer using ideas found in this lesson.
Check the road map and Figure 4 for the location of the island airports and outwash plains. Were you correct?
12. What geologic feature is Route 6 located on? Here are a series of questions to help you figure out an explanation.
Why do you think the highway engineers chose this location? Go back and examine Figure 3. When highway departments build a major roadway, the engineers try to use land where people's houses are not located so large numbers of people are not forced out of their houses by a process called eminent domain. The state can sometimes take a person's house and land when a judge can be convinced that such an action is in the public's good.
When Route 6 was being built, what piece of land was less populated with houses and why?
13. The three towns in this area that have the highest population are Falmouth, Barnstable(Hyannis), and Yarmouth. Locate these three towns on the contour map. What feature are they located on? Explain why builders might like to build on these sites.
Glaciers have played a most significant role in forming the surficial landscape of New England and other northern locations in the United States north of the Ohio and Missouri Rivers. There are other examples of glacial features influencing human settlement such as the location of golf courses and eskers which are former glacial melt stream beds consisting of sand. When you travel to Cape Cod or to other parts of New England, you will now be more aware of the influence of glaciers on the settlement of New England.
Coyle, Hal, ed. Project IMAGE: Investigative Materials About Global Environment.. Dubuque, Iowa: Kendall/Hunt, 1998.
Geography For Life: National Geography Standards 1994. Washington, D.C.: National Geographic Research and Exploration, 1994.
History and Social Science: Curriculum Framework. Massachusetts Department of Education, 1997.
Moore, W. G. A Dictionary of Geography. Baltimore, Maryland: Penguin Books, 1963.
Oldale, Robert. Cape Cod and the Islands: The Geologic Story. East Orleans, MA: Parnassus Imprints, 1992.
Strahler, Arthur. A Geologist's View of Cape Cod. Garden City, NY: The Natural History Press, 1966.
Strahler, Aruthur and Strahler, Alan. Modern Physical Geography, 4th ed. New York: John Wiley and Sons, 1992.
Fig. 3: Conditions close to the margin of an almost stagnant ice sheet are shown diagrammatically in the upper block diagram. (The area shown might be two to three miles across.) The lower block diagram shows the same area after the ice is entirely gone. Terminal moraine lies on the left; pitted outwash plain on the right. From Arthur N. Strahler, A Geologist's View of Cape Cod, orig. Natural History Press, New York, 1966.
Fig. 4: Generalized geologic map of Cape Cod and the Islands showing the locations of the end moraines (M) and adjacent terrains. Outwash plains and kame and kettle terrain older than the adjacent moraine. Outwash plains and kame or kettle terrain younger than the adjacent moraine. From Cape Cod and the Islands: The Geologic Story, by Robert N. Oldale, Parnassus Imprints, East Orleans, MA, 1992.
Fig. 5: Landsat false-color image of Cape Cod. NASA/Goddard Space Flight Center.
Topographic sections of Cape Cod below