Student Packet session # 11 Name: Date: Student Exploration: Building Pangaea Big Idea 6: Earth Structures Benchmark: SC.7.E.6.4 Explain and give examples of how physical evidence supports scientific theories that Earth has evolved over geologic time due to natural processes. (Also assesses SC.7.E.6.3.) SC.7.E.6.5 Explore the scientific theory of plate tectonics by describing how the movement of Earth s crustal plates causes both slow and rapid changes in Earth s surface, including volcanic eruptions, earthquakes, and mountain building. (Also assesses SC.7.E.6.1 and SC.7.E.6.7.) Vocabulary: continental drift, fossil, glacier, ice age, landmass, Pangaea, supercontinent Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Antarctica is a frozen land, so cold and icy that no trees can grow there. Yet scientists have discovered fossils (remains preserved in rock) of ancient trees in Antarctica. What do you think this means? 2. The Himalayas in central Asia are the tallest mountains in the world. But fossils of seashells can be found high in these mountains, far from any ocean. How do you think they got there? Gizmo Warm-up 1. The Gizmo allows you to drag and rotate all the major landmasses on Earth. To drag a landmass, grab it in the middle. To rotate a landmass, grab it near the edge. Learn the names of landmasses by holding the cursor over the landmass for a few seconds. Mark where you live. Drag an arrow from the purple bar at left to your location. 2. Test your geography skills. Drag and rotate landmasses randomly until you make a big mess. Then try to move them back to their original positions. When you have made the best map you can, click the camera icon in the upper right corner to take a snapshot. Then open a blank word-processing document and choose Paste. 3. Click Reset. Compare your map to the real one. How well did you do? 2011-2012 Science Saturday Enrichment Tutorial Page 1
Activity A: Solving the puzzle If necessary, click Reset. Check that the Evidence shown is None. Introduction: In 1915, a German scientist named Alfred Wegener (VAY-guh-ner) proposed the theory of continental drift. According to this theory, the landmasses once were joined into a supercontinent called Pangaea. The landmasses then slowly drifted to their current positions. Question: What did Pangaea look like? 1. Observe: Drag South America close to Africa. Look at their coastlines. What do you notice? 2. Explore: Try to fit all the landmasses together like a puzzle. As much as possible, avoid overlapping landmasses. When you are satisfied, take a snapshot and paste it into your document. Label this map fit of continents. 3. Analyze: Look at your map of Pangaea. A. How well do the continents fit together? B. Is it a perfect fit? Explain. C. Think about how the landmasses got from where they were to where they are today. Does it seem realistic that the landmasses could have moved like this? Explain. 4. Compare: If possible, present your map of Pangaea to your classmates and teacher. Look at other maps, and talk about each one. A. Are the maps very similar or very different? B. If Alfred Wegener showed you a map like this but did not have any other evidence, would you have believed his theory that the continents had moved? Explain. 2011-2012 Science Saturday Enrichment Tutorial Page 2
Activity B: Fossil and rock evidence Click Reset. Under Evidence choose Fossils. Question: What do fossils and rocks tell us about Pangaea? 1. Observe: The brown areas in the Gizmo show where fossils of Lystrosaurus have been found. Lystrosaurus looked a bit like a dinosaur, but lived in a time before dinosaurs. A. On which landmasses did Lystrosaurus live? B. Lystrosaurus probably couldn t swim very far. How might the locations of Lystrosaurus fossils be seen as evidence that the continents were once together? 2. Explore: Use the fossil evidence to help you make a new map of Pangaea. When the map is complete, take a snapshot and paste it into your document. Label this map fossil evidence. How well do the landmasses fit together this time? 3. Revise: Now under Evidence choose Rocks. The purple areas are mountains that formed when landmasses collided 450 million years ago. The orange areas show rocks that formed about 2 billion years ago. Adjust your map using this evidence, and then paste a snapshot of this map into your document. Label this map rock evidence. 4. Compare: If possible, compare your map to those of your classmates. A. How similar are the maps? B. If Wegener showed you this evidence, would you have believed his theory? Explain. 5. Extend your thinking: Click Reset and watch India closely. The Himalayan Mountains are found on the border of India and Eurasia. How do you think these mountains were formed? 2011-2012 Science Saturday Enrichment Tutorial Page 3
Activity C: Ancient ice sheets Click Reset. Under Evidence choose Glaciers. Introduction: Glaciers are large, slow-moving sheets of ice. During ice ages, glaciers formed at the North and South Poles and spread out to cover large areas. Question: What does evidence of glaciers tell us about Pangaea? 1. Observe: The white areas are places that show evidence of a massive ice sheet that existed around 250 million years ago. A. Which landmasses show evidence of ancient glaciers? B. Would you expect to find large glaciers on all of these landmasses today? Explain. 2. Explore: Drag the landmasses together to form a map of Pangaea. Try to line up the white areas on each continent. You can use the fossil and rock evidence as well if you like. Paste a snapshot of this map into your document, labeled Glacial evidence. 3. Analyze: Choose Glaciers (if necessary) and look at the white regions. Does this pattern make more sense now? Explain. 4. Extend your thinking: As glaciers moved away from the poles, rocks stuck to the bottom of the ice were dragged over the ground. This left scrapes and scratches on rock outcrops that can still be seen today. The scratches show which direction the glaciers moved. A. Look at the arrows that show the direction of glacial scratches. What is the pattern? B. Which landmass do you think was located over the South Pole in the time of Pangaea? Why? Discuss your answer with your teacher and classmates. Name: Date: 2011-2012 Science Saturday Enrichment Tutorial Page 4
Extension: Student Exploration: Plate Tectonics Big Idea 6: Earth Structures Benchmark: SC.7.E.6.4 Explain and give examples of how physical evidence supports scientific theories that Earth has evolved over geologic time due to natural processes. (Also assesses SC.7.E.6.3.) SC.7.E.6.5 Explore the scientific theory of plate tectonics by describing how the movement of Earth s crustal plates causes both slow and rapid changes in Earth s surface, including volcanic eruptions, earthquakes, and mountain building. (Also assesses SC.7.E.6.1 and SC.7.E.6.7.) Vocabulary: collisional boundary, convergent boundary, crust, divergent boundary, earthquake, lithosphere, mantle, plate, plate tectonics, transform boundary, volcano Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. Volcanoes are openings in Earth s crust where lava, gas, and ash can erupt. Where are active volcanoes located? 2. An earthquake is a violent shaking of Earth s surface. Where are earthquakes common? Gizmo Warm-up Volcanoes, earthquakes, mountains, and other features of Earth s surface owe their origin to the movements of plates: enormous, slowly-moving sections of Earth s crust. At plate boundaries, plates collide, move apart, move under or over each other, or slide past one another. The theory of plate tectonics describes how the plates move, interact, and change the physical landscape. The Plate Tectonics Gizmo shows a cross-section, or side view, of Earth. (Not to scale.) Above the cross section is a bird s-eye view of the same location. 3. Turn on Show labels. What are the layers of Earth that you can see? 4. Turn on Boundary name, and click on each boundary. What four boundaries do you see? 2011-2012 Science Saturday Enrichment Tutorial Page 5
Activity A: Sliding plates Select BOUNDARY A. Question: What happens when plates slide past one another? 5. Observe: Boundary A is a transform boundary. The arrows below the BOUNDARY A label will move the plates. Click the left arrow once to see how the plate moves. How would you describe the motion of plates in a transform boundary? 6. Sketch: Draw a bird s-eye view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved. Before movement After movement 7. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.) Highlight these locations on the map below. 2011-2012 Science Saturday Enrichment Tutorial Page 6
Activity B: Colliding continents Turn off Boundary name and Show location. Select BOUNDARY B. Question: What happens when two continents collide? 1. Observe: Boundary B is a collisional boundary. Click the left arrow four times to see how the plate moves. How would you describe the motion of plates in a collisional boundary? 2. Sketch: Draw a side view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved. Before movement After movement 3. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.) Highlight these locations on the map below. 2011-2012 Science Saturday Enrichment Tutorial Page 7
Activity C: Oceanic crust meets continental crust Turn off Boundary name and Show location. Select BOUNDARY C. Question: What happens when ocean crust collides with continental crust? 1. Observe: Boundary C is a convergent boundary. Click the left arrow four times to see how the plate moves. How would you describe the motion of plates in a convergent boundary? 2. Sketch: Draw a side view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved. Before movement After movement 3. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.) Highlight these locations on the map below. 2011-2012 Science Saturday Enrichment Tutorial Page 8
Activity D: Spreading plates Turn off Boundary name and Show location. Select BOUNDARY D. Question: How is new crust formed? 1. Observe: Boundary D is a divergent boundary. Click the right arrow four times to see how the plate moves. How would you describe the motion of plates in a divergent boundary? 2. Sketch: Draw a side view of the plate boundary before and after the plate motion. Draw an arrow to show which way the plate moved. Before movement After movement 3. Locate: Turn on Show location. Where on Earth can you find this type of boundary? (Note: You can refer to a world map or atlas for location names.) Highlight these locations on the map below. 2011-2012 Science Saturday Enrichment Tutorial Page 9
ASSESSMENT NAME: DATE: Big Idea 6: Earth Structures Benchmark: SC.7.E.6.4 Explain and give examples of how physical evidence supports scientific theories that Earth has evolved over geologic time due to natural processes. (Also assesses SC.7.E.6.3.) SC.7.E.6.5 Explore the scientific theory of plate tectonics by describing how the movement of Earth s crustal plates causes both slow and rapid changes in Earth s surface, including volcanic eruptions, earthquakes, and mountain building. (Also assesses SC.7.E.6.1 and SC.7.E.6.7.) Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The Earth is made up of several large, slow-moving tectonic plates that sometimes cause earthquakes. Which layer of the Earth contains these large plates? A. lithosphere B. mantle C. molten core D. solid core 2. The oldest rocks on Earth are found in Canada near the center of the North American Plate. Where would be the most likely place to find very young rocks? A. in Northern India, where the plates are colliding B. in the Hawaiian Islands, where a plate passes over a hot spot C. in Southern California, where two plates are sliding past each other D. in the middle of the South American Plate, where there is no plate boundary 3. What would be the most effective way for a scientist to get an idea of the actual age of a rock? A. Measure the relative amounts of radioactive elements in it. B. Judge its position in the rock face relative to that of other rocks. C. Measure the amounts of different forms of carbon it contains. D. Estimate how much of it has worn away since it formed originally. 4. Sometimes the layers in a rock face look as if they have been bent or broken. What is the most likely cause of this? 2011-2012 Science Saturday Enrichment Tutorial Page 10
A. uneven deposition of sediment as the rock formed B. folding and faulting in an earthquake C. weathering and erosion of some rock layers D. lava flows in a volcanic eruption 5. When archaeologists were looking for remains of the first British settlement in America at Jamestown, Virginia, they had to dig more than a meter into the ground before they began finding things the settlers had left, such as pottery, buttons, glass bottles, and wooden posts. Why did they have to dig so deep to find these things? A. The settlers must have buried their trash in deep pits for these things to be so far down. B. Over time, soil layers built up over the remains of the settlement and buried it. C. When the settlers had to leave, they hid their valuables underground. D. The weight of the houses they built made the items sink into the ground. 6. Why is it most likely that fossils will be found in sedimentary rock rather than igneous or metamorphic rock? A. Molten sedimentary rock burns up living organisms and fossilizes them as it cools. B. Animals can dig into sedimentary rock, and some are trapped inside and fossilize. C. Sedimentary rock breaks apart most easily, so fossils inside are seen more often. D. Organisms can get trapped and fossilize as the layers of sedimentary rock form. 7. In some places on Earth, large tectonic plates are moving toward each other and collide with great force. One such place is where the Indian plate and the Eurasian plate meet. What type of formation might occur where two tectonic plates collide? A. a canyon B. a rift valley C. a mountain range D. an earthquake 8. There are places on the surface of the Earth where two tectonic plates slide against each other, moving in opposite directions. Sometimes these plates become stuck and don't move for long periods of time, which causes a lot of energy to build between the two plates until there is too much energy and the plates slip, causing a sudden motion. What is the result of this sudden motion? A. mountains B. earthquakes C. volcanoes D. large valleys 2011-2012 Science Saturday Enrichment Tutorial Page 11
9. As the tectonic plates that make up the surface of the Earth move, they can cause rapid changes or slow changes to the Earth's surface. A rapid change to the Earth's surface due to the movement of tectonic plates results in the formation of which of the following? A. earthquakes B. volcanoes C. mountain ranges D. oceanic trenches 10. The surface of the Earth is made of several tectonic plates that move at a very slow rate. What causes the plates to move? A. explosions within the Earth's mantle B. convection currents within the Earth's mantle C. expansion of the Earth's core pushing on the tectonic plates D. contraction of the Earth's core pulling on the tectonic plates 2011-2012 Science Saturday Enrichment Tutorial Page 12