Satellite and Topographic Views

Transcription

1 TEKS 8.9C interpret topographic maps and satellite views to identify land and erosional features and predict how these features may be reshaped by weathering. Satellite and Topographic Views Objective: Compare topographic maps and satellite views to determine how erosion reshapes land features. Teacher Directions: In Advance: Materials: envelopes sets of description, photo, topographic map and satellite view cards Print; preferably in color; and laminate sets of the photos, descriptions, topographic maps, and satellite view cards. Each student group will investigate all of the 7 areas, so make enough so that each group will have access to all of the cards. Place the cards in envelopes for easy distribution. Activity Directions: Review features of topographic maps. Students will match the topographic map with the satellite view, then with the description and finally with the photo. Cards match as follows: Place Satellite View Topographic Map Emory Peak A 3 Monahans Sand Hills B 7 Enchanted Rock C 2 Rio Grande Valley D 1 Padre Island E 5 Meteor Crater F 4 Palo Duro Canyon G 6

2 Possible Answers: Palo Duro Canyon Meteor Crater How do the contour lines on the map show the canyon walls? The lines are close together along both sides of the river. Along the bottom of the canyon, there are fewer lines. What agent of erosion likely created the canyon? moving water How might the canyon be affected if a dam were built upstream of the river? Sediment would be deposited above the dam, so erosion would decrease below the dam. Describe the land feature created by the meteor impact. The feature is a depression or hollowed out bowl shape How is the land feature indicated on the topographic map? The contour lines have smaller, perpendicular lines showing that the elevation decreases How has erosion changed the crater? Erosion has deposited sediment into the crater, causing it to be less deep. Predict the effects of erosion on the canyon. The canyon would broaden and deepen over time. Predict what will happen to the land feature over time. Over time, the crater will likely fill with more sediment and eventually no longer be a depression. It will ultimately be buried. Emory Peak What land feature is Emory Peak? Emory Peak is a mountain On the topographic map, note the V shaped lines along the area labeled Boot. What do these lines represent? These lines represent a river flowing downhill. What erosional features are seen on the maps? Many rivers, valleys and small streams Predict how Emory Peak s shape may change over many years. As the mountain erodes, the sediment will be carried down the mountain slopes, causing the mountain to become more gently sloped and rounder less jagged.

3 Rio Grande River Valley Enchanted Rock Monahans Sand Hills Padre Island Compare the satellite photo and the topographic map. What differences do you see? Answers will vary, but students should notice that the satellite photo shows rectangular areas (agricultural), vegetation and buildings As more and more water is pulled from the river, the water flow slows. How might this effect the erosion of the river channel? The rate at which the river channel widens or deepens will slow. How would you describe Enchanted Rock based on the maps? The rock appears to be a dome shaped hill or mountain What is the highest elevation on Enchanted Rock? 1825 feet Which side of the rock would be easiest to climb and why? The South side would be easiest because the contour lines are further apart. Observe the areas of higher elevation on the topographic map and the light-colored areas on the satellite image. What force is most likely weathering and eroding these areas? Wind What is the elevation along the shoreline? sea level or 0 feet Why is only one contour line shown? The area is basically flat What two land features are found along the shoreline? beaches and sand dunes How might a hurricane impact the area? A hurricane would change the force of the water along the shore, causing more erosion. This would change the shape of the island. How will the shape of the river channel change as the river continues to flow? Eventually, the river channel will deepen and widen, the river will continue to become more curved. One agent of erosion at Enchanted Rock is exfoliation. Rock breaks off in large sheets slides to the bottom of the rock. What force causes the sheets of rock to slide down hill? gravity How will the shape of the rock change over time? If the sides continue to erode away, the rock will become more rounded, but smaller List at least three ways the sand hills will change due to weathering, erosion and deposition. The dunes will change shape, size and location People living along the shore are concerned about the beaches disappearing. Why is this concern valid? As water and wind exert force along the shore, the shoreline is eroded away, which virtually causes the beach to disappear.

4 TEKS 8.9C interpret topographic maps and satellite views to identify land and erosional features and predict how these features may be reshaped by weathering. Satellite and Topographic Views Objective: Compare topographic maps and satellite views to determine how erosion reshapes land features. Directions: Observe the characteristics of each map. Match the topographic map with the corresponding satellite image. Match the description card with the corresponding map and image. Match the photo with the corresponding description, map and image. Answer the questions for each set. Palo Duro Canyon cards and Meteor Crater cards and How do the contour lines on the map show the canyon walls? What agent of erosion likely created the canyon? How might the canyon be affected if a dam were built upstream of the river? Describe the land feature created by the meteor impact. How is the land feature indicated on the topographic map? How has erosion changed the crater? Predict the effects of erosion on the canyon. Predict what will happen to the land feature over time.

5 Emory Peak cards and What land feature is Emory Peak? On the topographic map, note the V shaped lines along the area labeled Boot. What do these lines represent? What erosional features are seen on the maps? Predict how Emory Peak s shape may change over many years. Rio Grande River Valley cards and Compare the satellite photo and the topographic map. What differences do you see? As more and more water is pulled from the river, the water flow slows. How might this effect the erosion of the river channel? How will the shape of the river channel change as the river continues to flow?

6 Enchanted Rock cards and Monahans Sand Hills cards and Padre Island cards and How would you describe Enchanted Rock based on the maps? What is the highest elevation on Enchanted Rock? Which side of the rock would be easiest to climb and why? Observe the areas of higher elevation on the topographic map and the light-colored areas on the satellite image. What force is most likely weathering and eroding these areas? What is the elevation along the shoreline? Why is only one contour line shown? What two land features are found along the shoreline? How might a hurricane impact the area? One agent of erosion at Enchanted Rock is exfoliation. Rock breaks off in large sheets slides to the bottom of the rock. What force causes the sheets of rock to slide down hill? How will the shape of the rock change over time? List at least three ways the sand hills will change due to weathering, erosion and deposition. People living along the shore are concerned about the beaches disappearing. Why is this concern valid?

7 Description Cards Enchanted Rock State Park, near Fredricksburg, Texas Enchanted Rock is an enormous granite dome formation found in Central Texas. The dome rises about 425 feet above the surrounding area. The rock was formed about 1,082 million years ago when molten rock pushed up through the surrounding rock. The rock is known for its moaning which occurs when the rock cools and contracts after being heated during the day. This also causes the granite to split off the dome in sheets. Average rainfall in the area is about 31 inches per year. The temperature can vary by 23 degrees between day and night. Rio Grande River Valley, near Rio Grande City, Texas The Rio Grande River flows from Colorado through New Mexico and along the Texas Mexico border until it joins the Pecos River and heads to the Gulf of Mexico. Near the river s mouth, is an important agricultural region, where the river ends in a sandy delta. The use of water from the river has slowed the flow of the river tremendously over the years. Less than a fifth of the water reaches the Gulf of Mexico today. Meteor Crater, near Odessa, Texas This is the site of one of two meteor impacts found in Texas. Thousands of meteors fell about 63,500 years ago. The crater was originally about 100 feet deep, but over time, soil and debris have filled the crater to a depth of about 15 feet deep.

8 Emory Peak, Big Bend National Park, Texas Emory Peak is part of the Chisos Mountains, which lie in the heart of Big Bend National Park. The Park is located in far West Texas. Emory Peak is the highest point of the Chisos Mountains at 7825 feet above sea level. These mountains are volcanic and formed million years ago during volcanic eruptions and intrusions. Over time, seasonal streams flow downhill and have carved away much of the mountain slopes, leaving many channels and gullies behind. Monahans Sandhills State Park, near Monahans, Texas The Monahans Sandhills State Park is located in West Texas and consists of 3840 acres of sand dunes, some of which are up to 70 feet high. The area receives little annual precipitation, but has seasonal winds which reshape the landscape. Most of the dunes are stabilized by vegetation, but many dunes are still active. The prevailing winds in the area change the shape and size of the dunes. Palo Duro Canyon, near Amarillo, Texas The Palo Duro Canyon, sometimes called the Grand Canyon of Texas, is located in the high plains of North Texas. The canyon was formed by the Prairie Dog Town Fork Red River. The canyon varies from a depth of 820 to 997 feet. Average annual precipitation is 20 inches per year, and flash flooding is a major concern in the canyon. Padre Island, near Corpus Christi, Texas Padre Island is the largest Texas barrier island and the world's longest barrier island. Barrier islands are long, narrow strips of sand that provide protection for mainland areas. They are usually separated from the mainland by a shallow bay or lagoon. Padre Island is located on Texas' southern coast of the Gulf of Mexico and is famous for its white sandy beaches at the south end. The average annual rainfall varies from 30 to 50 inches per year.

9 Photos Enchanted Rock Monahans Sand Hills Rio Grande Valley

10 Photos Meteor Crater Palo Duro Canyon Emory Peak Padre Island

11 Satellite and Topographic Maps A 3

12 C N 2

13 B 7

14 E 5

15 F 4