Plate Tectonics: Our Dynamic Planet. Description

Transcription

1 TEACHER GUIDE Plate Tectonics: Our Dynamic Planet 90 Minute Earth Science Lesson Gallery Program Grades: 4-8 Plate Tectonics: Our Dynamic Planet Description Journey to the interior of the Earth and discover how our planet s internal structure affects the way the surface features are expressed. Plate motions, volcanic and earthquake activity, and the heat within the planet are some of the powerful ways our Earth changes. This action also relates to the rock cycle and what we see on our planet. Objectives Explain the connection between Earth s internal structure and the motions of the plates and earthquakes List five types of plate interactions Describe the locations of most of Earth s earthquake and volcanic activity Distinguish between two major volcanic types and the reasons for the difference in their eruptive styles Discuss the positive and negative aspects of plate motions, volcanic and earthquake activity Determine the relationship between earthquakes, volcanoes and the rock cycle Ohio s Learning Standards Grade 4: Earth and Space Science Earth s Surface Earth s surface has specific characteristics and landforms that can be identified. The surface of Earth changes due to weathering. The surface of Earth changes due to erosion and deposition. Grade 6: Earth and Space Science Rocks, Minerals and Soil Igneous, metamorphic and sedimentary rocks form in different ways.

2 Ohio s Learning Standards Continued Grade 8: Earth and Space Science - Physical Earth The composition and properties of Earth s interior are identified by the behavior of seismic waves. Earth s crust consists of major and minor tectonic plates that move relative to each other. A combination of constructive and destructive geologic processes formed Earth s surface. Evidence of the dynamic changes of Earth s surface through time is found in the geologic record Before Your Museum Visit If this will be your first trip to the Museum for your students, you may want to discuss the following: What is a Museum? What is our purpose for visiting The Cleveland Museum of Natural History? How should we handle objects at the Museum? Introduce the vocabulary and additional resources provided below. Vocabulary aesthenosphere - A layer of the mantle that is more plastic than the hard lithosphere. Although it reacts to earthquake waves like a solid, portions of the aesthenosphere, under the high pressure and temperature of the deep Earth, give and move or allow the crust to move over them. composite volcano - steep-sided mountain built by layers of ash, lava and other volcanic products. These are usually the most dangerous volcanoes. (Also called stratovolcanoes) convergent boundary - Areas where two plates are colliding with each other. They include three types: Ocean- ocean collisions which create island arc systems, ocean- continent collisions which create coastal mountain chains and continent- continent collisions which form large interior mountain systems. core - The innermost layer of the Earth, composed of iron and nickel. crust - The outermost layer of the Earth. Oceanic crust is lighter and composed mostly of granite. divergent boundary - Areas where two plates are separating from each other to form new ocean floor crust. The mid-ocean rift system is the largest continuous mountain chain in the world- over 40,000 miles long- but hidden from our view by the world s oceans. earthquake - the shaking of the ground produced by earth movement along a fault

3 fault - a break in the rocks along which there has been movement hot spot - An area of the mantle which contains plumes of hotter material. Hot spots can create volcanic activity in the crust above them. igneous rock rock that has cooled from a molten condition, either at the surface or below the Earth s surface lava - molten rock on the surface of the Earth lithosphere - the crust and the upper part of the mantle that are solid rock and form the plates magma - molten rock within the Earth. mantle - the layer of the earth between the crust and the core metamorphic rock - a rock that has been changed by heat, pressure or heat and pressure together obsidian - a volcanic rock that cooled so fast that no mineral crystals could form: a natural glass plate a section of the lithosphere that moves as a unit plate tectonics - the theory of the Earth s behavior that states that the crust is composed of a series of major plates, and some minor ones, which move relative to each other. They slide on the aesthenosphere. Their relative motions of collision, separation and sliding create the majority of the Earth s volcano and earthquake activity. plutonic rock - melted rock that cooled and became hard within the Earth's crust. Slow cooling below the surface produces large mineral crystals. pumice - a volcanic rock containing so many bubbles that it will actually float on water sedimentary rock - rock composed of sediment that have been deposited by water, wind or ice shield volcano - a volcano with relatively gentle slopes produced by numerous flows of rather fluid lava. These are the largest of the volcanoes. transform boundaries - places where two plates are simply sliding past each other. The San Andreas Fault is a remarkable boundary between two sliding plates. Northern California is part of the North American plate; southern California is part of the Pacific plate. volcanic rock - melted rock that cooled and became hard on the Earth's surface. Fast cooling on the surface produces very small mineral crystals. volcano - a place on the Earth's surface through which molten rock, gases, and solid material from within the Earth is expelled onto the surface OR the mountain resulting from the above process

4 Extension Activities 1. On a world map, plot the locations of active volcanoes and recent earthquakes. Scan the news for reports of recent eruptions and earthquakes to add to your map. Notice any pattern of occurrence that might result. Do these new earthquakes and eruptions occur along plate boundaries? 2. To understand why subducting ocean plates produce island arcs, you need a knife and a round fruit - oranges or grapefruit work well. CAREFULLY cut part way into the fruit with the blade straight up and down. The cut will appear as a straight line. But plates don t go straight down into the Earth, the subducting plate descends at about a 45- degree angle. CAREFULLY make another cut, this time holding the blade at about 45 degrees. Note the cut now appears as an arc across the surface. Compare this arc with the Aleutian Islands in the North Pacific. Can you locate other island arcs? 3. Make a small package of jello. Pour into a small flat pan (roughly 11 x 7). Refrigerate and allow to set. Make some cuts through the layer, try curves and straight lines. Place pan briefly in warm water to loosen the bottom. Now try pushing from both ends. How does the jello react? What happens at the faults? 4. Hard boil an egg, but do not remove the shell. Slice it in half including the shell. How is the cross-section of the egg similar to the cross-section of the Earth? How is it different? (Math exercise: Measure the thickness of each layer. Find a cross-section of the Earth with the dimensions of each layer given. If the Earth were reduced to the size of the egg, would the egg layers be in the correct proportion? 5. Use a large metal mixing bowl (or a bell if you can find one). Once the metal is struck, it begins to vibrate. Those vibrations can be felt by gently touching the metal. These vibrations are like the earthquake waves that are transmitted through the Earth. What happens if you really grab the metal? (You dampen - stop - the vibrations.) 6. Can volcanoes be helpful? Locate places such as volcanic islands or volcanoic mountains and find out if people live there. What are some of the benefits? Are all volcanoes dangerous? What are the dangers of living on or near a volcano? 7. Build a model house, skyscraper and other structures from cardboard, popsicle sticks, etc. Simulate the waves of an earthquake, up and down or side to side, with a piece of flexible cardboard. Place your structure(s) on the cardboard and create a `quake. What happened to your structure? What if your city was located near an ocean and the sea water sloshed around, what other disaster could occur?

5 Online Resources for Teachers and Students Click the link below to find additional online resources. These websites are recommended by our Museum Educators and provide additional content information. CMNH Educators regularly review these links for quality. Web addresses often change so please notify us if any links have issues. Please note that aside from our own Museum website, the Museum is not affiliated with and does not endorse these online resources. Cleveland Museum of Natural History Educator Resource Center (ERC) The Educator Resource Center offers educator workshops, thematic teaching kits, animal dioramas, and more for loan to area teachers. Contact the ERC at for information on individual or school membership. Visit the Museum s ERC website for more information on workshops Hours o Tuesday through Friday, 2 to 5 PM o Wednesday, 2 to 6 PM o Saturday, 9 AM to 1 PM o Closed Sunday and Monday Materials for Loan If you re interested in additional resources be sure to check out the following ERC materials or browse ERC materials online at Related ERC kits for this topic include: Landform Model: Landform model featuring glaciers, coastline, folded mountains, fault block mountains, canyon, coastal plain, and a volcano. Plate Tectonics, Volcanoes and Earthquakes: Take off on an adventure and explore the active Earth through activities about earthquakes, volcanoes, and plate tectonics. Volcano diorama Mini Kit: Compliments the Volcano diorama. Books and volcanic rock samples are included.