The Theory of Plate Tectonics - PDF Free Download

Edit File QUICK LAB The History of Plate Tectonics At one time, cars did not have seat belts or air bags. At that time, the thoughts about car safety consisted of controlling speed and making cars heavy so they could better withstand a crash. Look at cars today. Seat belts are essential. Air bags are standard features, and the materials and the design that go into a car make it stronger and safer, but not necessarily heavy. These changes and improvements came gradually; they did not occur overnight. Through research and testing, scientists and designers became more aware of what makes cars safe, so their ideas and hypotheses of car safety were revised as more and more things were discovered. Hypotheses changed, and they continue to do so. Just as new information changed our thoughts on cars and car safety, new evidence also changed hypotheses related to Earth s moving continents and changing features. In this lab, you will examine how the hypothesis of continental drift and the discoveries that came after provided a means to develop the theory of plate tectonics. You will find out how this affected both scientists and society over time. You will use a computer or other resources to construct a timeline that shows the key ideas and scientists that played a role in the development of our understanding of plate tectonics. PROCEDURE Obtain a poster board you can use for a timeline. The timeline should be long enough and tall enough to show information about several events. As you work with your group constructing a timeline, sequence the following events. You might assign a few events for each person in your group to research. For each point, find additional information from the Internet or other sources so that you can write a few sentences about each one on your timeline. You should find a date or date range, any people involved, and any other important information about each point. While you research, if you find additional discoveries that are not on the list, add and discuss them with your group. Identical rock layers and fossils discovered on separate continents Identical glacial weathering patterns discovered on separate continents Pangaea proposed Pangaea proposed to have broken up into Laurasia and Gondwanaland Continental drift proposed OBJECTIVES Describe the historical development of the theory of plate tectonics. MATERIALS Internet access markers meter stick poster board scissors ScienceFusion 372 Unit 7, Lesson 1

Quick Lab continued Sea-floor spreading discovered Magnetic reversal patterns discovered Theory of plate tectonics first presented Did you find anything that you thought was important in the development of plate tectonics but was not on the list? If yes, was it related to research and observation? Did the scientific community accept continental drift when it was first proposed? Explain why or why not. What key discovery led to acceptance of the fact that continental and oceanic crustal plates move, and that the movement can be explained by specific Earth processes? ScienceFusion 373 Unit 7, Lesson 1

Quick Lab continued How did the discovery that earthquakes are related to plate boundaries impact scientific research and society? Once you find all the information you need, set up a time scale on your timeline so you can correctly display the events and hypotheses. If your poster board isn t very long, you might want to use several rows to show your timeline. Compare your timeline to those of other groups in your class. Describe any differences. How does the research that was conducted in developing the theory of plate tectonics continue to have an impact on society and different fields of science? ScienceFusion 374 Unit 7, Lesson 1

Edit File QUICK LAB Magnetic Reversals and Plate Tectonics Tectonic plate movement has helped scientists understand how continents have shifted over time during Earth s history. One of the key pieces of evidence leading to the theory of plate tectonics is the magnetic reversal pattern found in the lithosphere s crustal rocks. These patterns are found on the sea floor, on either side of the mid-ocean ridge where seafloor spreading occurs. In newly forming oceanic crust, magnetic minerals line up with Earth s north and south poles like mini-magnets. They remain in this position after the rock hardens. Throughout Earth s history, Earth s magnetic field has reversed many times. Each time the pole s magnetic polarity changed, the newly forming minerals in the rock aligned in a direction to match magnetic north and south. This discovery was important in understanding how tectonic plates moved, and provided crucial evidence that led to the theory of plate tectonics. In this activity, you will implement an investigation by making observations. You will use your observations to model magnetic reversal patterns and relate them to plate tectonics. The advantages and limitations of your model will be considered. OBJECTIVES Model and compare magnetic reversal patterns and relate them to plate tectonics. MATERIALS For each group chalk, colored, several colors meter sticks, 2 paper, adding machine, 2 m or longer stopwatch or clock with second hand large, hardcover books, 2 PROCEDURE Examine the diagram on the next page. This diagram is a model of magnetic reversal patterns found in oceanic crustal rocks. New rock is continually being formed at the mid-ocean ridge. Are we in a period of normal or reverse polarity? Why do you think the patterns are mirror images of each other on either side of the mid-ocean ridge? Observe the magnetic patterns in the diagram. Approximately how many times has the magnetic orientation changed in the past 4 million years? ScienceFusion 377 Unit 7, Lesson 1

Quick Lab continued Use the materials provided and your observations of the diagram to model magnetic reversals. Start by placing the textbooks on the table, spine to spine. Place one strip of paper under each book so that one end of each paper comes up between the spines. What does each paper represent? Have two students in your group each hold one end of each paper strip between the books. They will pull the strips slowly at the same time across the tops of the books. What does the place where the two books meet represent? One person in your group will be the timer. That student will call out normal polarity or reverse polarity every 5 seconds, alternating the terms as the paper is slowly but steadily pulled outward from the center of the books. Two other students in your group will hold chalk against the paper on the edge of each book edge as the paper strips are pulled up and across each book. No chalk marks are made on the paper strips during reverse polarities. Perform the activity. When the timer says normal polarity, slowly start pulling the paper between the books while pressing down on the chalk. When the timer says reverse polarity, stop making chalk marks on the paper, but continue pulling the paper. ScienceFusion 378 Unit 7, Lesson 1

Quick Lab continued After all the paper has passed through the books, lay the papers out side by side and compare them. Explain what you see, and describe how your model compares with actual magnetic reversal data. How does your model relate to scientific explanations about magnetic reversals found in crustal rock? How did scientists use the information about magnetic reversals to explain why crustal plates move? ScienceFusion 379 Unit 7, Lesson 1

Edit File EXPLORATION LAB Modeling Geological Evidence In some ways, scientists are like detectives. They rely on empirical evidence from their investigations to answer questions. Empirical evidence is obtained when scientists make observations and collect data. Evidence to support a theory is often accumulated over time by different scientists. Some scientists repeat other scientist s investigations to confirm their results, while others try to test the same ideas using different kinds of procedures. This is how the theory of plate tectonics developed. In fact, evidence is still being collected the theory is still being refined today. In this lab activity, you will research one of the pieces of evidence that was used to support the theory of plate tectonics. In the first class period, you will research a scientific explanation related to an Earth process that was used as evidence in support of the theory of plate tectonics. You will analyze and evaluate the explanation by making observations and describing how it explained tectonic movement of the Earth s crustal plates. In the second class period, you will use the explanation and evidence you studied to construct a model of a particular tectonic process. OBJECTIVE Analyze and evaluate scientific explanations in the development of the theory of plate tectonics by using empirical evidence. MATERIALS Internet access markers modeling clay poster board PROCEDURE IDENTIFY A PROBLEM Below is a list of scientific discoveries and ideas that provided evidence to explain and support the theory of plate tectonics. Choose one of these topics to research. You may also choose a valid research topic that is not on this list. Earth s physical layers and mantle convection Earth s lithospheric plates (tectonic plates) mid-ocean ridges deep-ocean trenches sea-floor spreading continental drift magnetic reversals location of trenches, volcanoes, and earthquakes ScienceFusion 384 Unit 7, Lesson 1

Exploration Lab continued RESEARCH A PROBLEM Use the Internet, your textbook, or other resources to research a scientific explanation that is used to support the theory of plate tectonics. As you do your research, make observations and evaluate how the evidence from the study supports our current understanding of this theory. Answer these questions as you conduct your research. (a) What topic have you chosen to research? (b) During what time period was the study conducted? For this topic, were multiple studies conducted over time? (c) Name the scientists who participated in this research. (d) What evidence, including quantitative data and qualitative observations, was collected? How was it collected? ScienceFusion 385 Unit 7, Lesson 1

Exploration Lab continued (e) Based on the evidence, what conclusions were made? Describe how the conclusions support the theory of plate tectonics. (f) What other pieces of evidence could researchers collect to further investigate this topic? What unanswered questions need further investigation? DEVELOP A PLAN After you have completed your research, decide how your group can construct a model that represents a piece of observational evidence that was used to support the theory of plate tectonics. You can use the materials provided, request additional materials from your teacher, or provide your own materials. Sketch and label a plan for your model. Have your teacher approve your plan before you proceed. ScienceFusion 386 Unit 7, Lesson 1

Exploration Lab continued BUILD A MODEL Build a model that represents how empirical evidence was used to support the theory of plate tectonics. ANALYZE THE RESULTS Analyzing Models Share your model with other classmates. Examine the models made by other groups. Describe the other empirical evidence that has led scientists to support the theory of plate tectonics. What time period did this span? TO THE ESSENTIAL QUESTION Applying Concepts Why is it important for scientists to use empirical evidence to support their scientific explanations? ScienceFusion 387 Unit 7, Lesson 1

EXPLORATION LAB Modeling Geological Evidence In some ways, scientists are like detectives. They rely on empirical evidence from their investigations to answer questions. Empirical evidence is obtained when scientists make observations and collect data. Evidence to support a theory is often accumulated over time by different scientists. Some scientists repeat other scientist s investigations to confirm their results, while others try to test the same ideas using different kinds of procedures. This is how the theory of plate tectonics developed. In fact, evidence is still being collected the theory is still being refined today. In this lab activity, you will research one of the pieces of evidence that was used to support the theory of plate tectonics. In the first class period, you will research a scientific explanation related to an Earth process that was used as evidence in support of the theory of plate tectonics. You will analyze and evaluate the explanation by making observations and describing how it explained tectonic movement of the Earth s crustal plates. In the second class period, you will use the explanation and evidence you studied to construct a model of a particular tectonic process. OBJECTIVE Describe the historical development of the theory of plate tectonics. MATERIALS Internet access markers modeling clay poster board PROCEDURE IDENTIFY A PROBLEM You will use the Internet, your textbook, or other resources to research a scientific explanation that is used to support the theory of plate tectonics. Begin your research by making a list of the types of evidence that have led scientists to develop the theory of plate tectonics. ScienceFusion 388 Unit 7, Lesson 1

Exploration Lab continued RESEARCH A PROBLEM Choose one of your topics listed to further research the discovery and development of the process and observations and evidence that were used to support the theory of plate tectonics. As you conduct your research, make observations and evaluate how the evidence from the study supports our current understanding of this theory. Answer these questions as you conduct your research. (a) What topic have you chosen to research? (b) During what time period was the study conducted? For this topic, were multiple studies conducted over time? (c) Name the scientists who participated in this research. (d) What evidence, including quantitative data and qualitative observations, was collected? How was it collected? ScienceFusion 389 Unit 7, Lesson 1