Tectonic Forces Simulation: Volcanoes Activity One

Transcription

1 Tectonic Forces Simulation: Volcanoes Activity One Introduction Volcanoes form above vents or cracks in the earth's crust. When a volcano erupts, magma is forced up through the cracks - sending lava, ash, and gas into the air. Since the volcano's force comes from deep within the earth, it's not surprising that they occur along the edges of tectonic plates - the large pieces of earth's crust that fit together like pieces of a puzzle. The edges of these plates either collide against each other at convergent boundaries, slide past each other at transform boundaries, or move away from each other at divergent boundaries. There are three types of convergent boundaries, depending on whether they bring together two ocean plates, two continental plates, or an ocean plate and a continental plate. Directions Using the tectonic forces simulation, look at volcanic activity along convergent boundaries where ocean and continental plates meet. Procedure 1. Read Start Here and close the window. For more information, click Background and close the window. For detailed directions, click Help and read "How to Use this Simulation." 2. Click on the "Choose a type of plate boundary" pull-down menu and select Convergent (Ocean & Continental). 3. Your goal is to find the different types of tectonic activity and geographic features that occur along Convergent (Ocean & Continental) plate boundaries. Convergent plates collide against each other. One by one, click the different types of Tectonic Activity. If the graphic for that type of activity overlaps the plate boundaries, leave the box checked. If that type of activity doesn't occur along the plate boundaries, click the box again to remove the selection. Do the same thing with Geographic Features. 4. Record the outcomes in the chart below by placing an "X" in the places where you found a match. (Note: A "Correct!" box pops up when you've checked all the types of tectonic activity and geographic features that occur along those plate boundaries.)

2 Tectonic activity Geographic features Island arc Mountain chain Deep sea trench Mid-oceanic ridge Rift zone Volcanoes Int. and deep Shallow Divergent Transform 5. What other type of tectonic activity and geographic features occur at these boundaries? 6. Name two places where volcanoes occur along this type of plate boundary. (Click on the yellow circles that appear when you find all the matches.) Besides volcanoes, what do these places have in common? 7. What important event in U.S. history occurred along this type of plate boundary?

3 Tectonic Forces Simulation: Volcanoes Activity Two Introduction Volcanoes form above vents or cracks in the earth's crust. They often occur along the edges of tectonic plates - the large pieces of earth's crust that fit together like pieces of a puzzle. In the first activity, you looked at volcanic activity along one type of plate boundary. In this activity, you'll compare volcanic activity along several types of plate boundaries. Directions Using the tectonic forces simulation, compare volcanic activity along different plate boundaries. Procedure 1. Read Start Here and close the window. For more information, click Background and close the window. For detailed directions, click Help and read "How to Use this Simulation." 2. Find the different types of tectonic activity and geographic features that occur along different plate boundaries. To begin, choose a Plate Boundary from the pull-down menu. Then select the different types of Tectonic Activity and find the ones that occur along those boundaries. Do the same thing with Geographic Features. 3. Follow these steps for each of the five types of plate boundaries. Record the outcomes in the chart below by placing an "X" in the places where you found a match. (Note: A "Correct!" box pops up when you've checked all the types of tectonic activity and geographic features that occur along those plate boundaries.) Tectonic activity Geographic features Island arc Mountain chain Deep sea trench Mid-oceanic ridge Rift zone Volcanoes Int. and deep Shallow Divergent Transform

4 4. Are and volcanoes always found along the same types of plate boundaries? Explain. 5. Can volcanoes erupt in the ocean? Give an example to support your answer. 6. Alaska's Aleutian Islands occur where two ocean plates converge. Besides volcanoes and, what other natural disasters are common there? (To learn more about these islands, click the yellow circles that appear when you find all the matches for those plate boundaries.) 7. Where do most of the world's volcanoes occur? Use the simulation to find the types of plate boundaries where volcanoes are most common. Begin by selecting a type of plate boundary, then click Volcanoes. Mark major areas of volcanoes on the map below using red dots. Then each time you find where an area of volcanoes corresponds with a plate boundary, write the letter for the plate boundary next to it. (See the key below.)

5 Key A Divergent B Convergent (O&C) C Convergent (C&C) D Convergent (O&O) E Transform 8. What are the two types of plate boundaries where most volcanoes occur? 9. The Ring of Fire is a term for the huge chain of volcanoes that encircle the Pacific Ocean. Highlight the Ring of Fire on the map above. What types of plate boundaries make up the Ring of Fire? 10. The Hawaiian Islands were formed by volcanic eruptions. Draw an X on the map above to show where Hawaii is located. What types of plate boundaries do you find there? What does this tell us about volcanoes and plate boundaries?