Slide 1 / 107 Slide 2 / 107 6th Grade Earth's Systems Part 2: Plate Tectonics and Natural Disasters 2015-10-15 www.njctl.org Slide 3 / 107 Slide 4 / 107 Table of Contents: Plate Tectonics and Natural Hazards Click on the topic to go to that section Pangaea · Pangaea Energy Flow · Types of Plate Interactions and the Results · Natural Disasters · Return to Table of Contents Slide 5 / 107 Slide 6 / 107 Activity Follow-up - Similar Fossils Plate Tectonics Intro Lab Image: NASA At this point in your life, you are probably very familiar with this map of our Earth's appearance. In the last activity, you saw that areas that are very far away Throughout human history, the continents have been from each other above ended up having similar fossils. Many positioned just like you see above. Fossil records hint at of the areas that match up are even separated by an ocean! something different though. Complete the activity to learn more!
Slide 7 / 107 Slide 8 / 107 Match Up the Excavation Pairs Possible Hypotheses: Move the place on the right to match the one on the left. Below, record some of the hypotheses proposed that tried to explain the mystery of the common fossils: Southport, SC, USA Natal, Brazil Algiers, Algeria Darwin, Australia Western Antarctica Dakar, Senegal Barcelona, Spain Easter Antarctica Lagos, Nigeria Dar es Salam, Tanzania Slide 9 / 107 Slide 10 / 107 Continental Drift Continental Drift ? Scientists have tried for years to solve this mystery. One proposed theory is known as continental drift. This concept was first presented by a German scientist named Alfred Wegener in 1912. Wegener theorized that all of the continents were once connected in one large land mass. He stated that the land then "drifted" apart, forming the land we see today. Although Wegener provided much evidence supporting his theory, he did not yet know what caused the continents to seemingly travel across the oceans. Slide 11 / 107 Slide 12 / 107 Plate Tectonics Plate Tectonics Scientists in the 1960s worked to prove Wegener's idea and developed the theory of plate tectonics. This theory states that the Earth's surface is broken into large, rigid pieces (called It is the movement of these plates plates) that move independently of each other. that cause changes in the Earth's geographical features, What do you think happens when including mountains and these plates move around the volcanoes, as well as the shapes surface of Earth? of the continents. Talk at your table to come up with some ideas.
Slide 13 / 107 Slide 14 / 107 1 What is the outermost layer of Earth called? 2 What is the thinnest layer of Earth called? Mantle Mantle A A Crust Crust B B Inner Core Inner Core C C Outer Core Outer Core D D Slide 15 / 107 Slide 16 / 107 The Continents of the World Pangaea Compare the map on the previous page to the one below. The green represents land and the modern continents are outlined: Europe/Asia What similarities / differences do you see between the two images? N. America Africa S. America Australia Antarctica Antarctica Australia Asia Europe North South Africa America America Slide 17 / 107 Slide 18 / 107 Pangaea Think Back on Our Activity... Wegener's theory of continental drift popularized the idea that there was once a "supercontinent," now called Pangaea. This large land mass broke apart slowly over 200 million years ago, creating the continents that we see today. The image on the left gives you an idea of how this transition happened. How can we use the theory of the Pangaea supercontinent to explain the results of our fossil activity from earlier in this unit?
Slide 19 / 107 Slide 20 / 107 Evidence of Pangaea 3 Similar Mesosaurus fossils would be found in which two areas? Africa and India A Australia and South America B Antarctica and Africa C South America and Africa D Slide 21 / 107 Slide 22 / 107 Evidence of Pangaea Evidence of Pangaea Even though the continents shown above are now many Notice that a fern miles apart, when they were all plant called together as one Glossopteris once supercontinent, inhabited the land Pangaea, the plants and that is now animals were able to spread Antarctica. across these modern barriers. This causes there to be similar fossils in these now far-apart continents. Do you think you can still find this plant there? Why or why not? Slide 23 / 107 Slide 24 / 107 Evidence of Pangaea 4 Which can be used as an indicator of past climate and weather? There are non-living clues that support this theory as well. The rocks that make up our Earth hint at the fact that Pangaea once Fossils A existed. Lava flow For example, the Appalachian Mountains in North America and the B Caledonian Mountains in Europe are similar in age and structure and Mountain ranges are made of the same rock types. C Ocean tides D Appalachian Mountains Caledonian Mountains
Slide 25 / 107 Slide 26 / 107 Motion of the Continents 5 Which of the following can be used to show continents used to be next to each other in Pangea? Pangaea was not the only supercontinent that has formed on Earth, but it is the most recent one. Fossils A Similar Animals B Mountain ranges C all of the above D The image above shows how the land was distributed around 600 million years ago. 200-300 million years before Pangaea! Slide 27 / 107 Slide 28 / 107 Activity - Changes in the Land 6 Which of the following statements is NOT evidence of continental drift? The continents below are still moving but we don't notice a difference because of how slow the changes are. Similar fossils A Use the accompanying worksheet to determine how quickly our Matching coastlines excavation sites from the introduction activity are moving apart. B Similar present-day weather C Matching mountain ranges D Slide 29 / 107 Slide 30 / 107 The Energy of the Earth Earth's energy comes from two different places. What are those 2 places? Energy Flow Return to Table of Contents
Slide 31 / 107 Slide 32 / 107 Solar Energy Earth's Internal Energy We have discussed previously how the energy from the Sun (a/k/a solar energy ) impacts Earth. Use the pictures and the lines The energy needed to cause the changes seen in our last below to list 3 ways Earth's organisms use energy from the Sun. section though comes from beneath the surface of Earth. __________________________________ The heat of the inner core, outer core and mantle is linked to many large scale Earth processes such as plate __________________________________ tectonics, geysers, and volcanic eruptions. __________________________________ Slide 33 / 107 Slide 34 / 107 Convection in the Earth's Mantle Heat Transfer: Convection You may have heard the term "convection" before in reference to a convection oven: The materials in Earth's mantle are constantly in motion. As you travel through the mantle, the temperature changes. Convection refers to the warming of a substance To distribute this heat evenly, caused by the circulation of there are convection currents different temperatures of air. that move between the warmer and cooler sections. These currents are able to travel through the semi-solid rock in the In a convection oven, a fan helps circulate the warm and cool air mantle, causing changes to the land above. so that the food inside heats evenly. Slide 35 / 107 Slide 36 / 107 Differences in Air Temperature Warm vs Cool Air As air temperature changes, so does its density and its The process of convection works because warm air and cool air behavior. behave differently. Warm air rises . This same phenomenon happens Think back on your fire with all gases and safety rules.. if there is smoke in a room, liquids (such as ocean water) and also why is it important that happens in the semi- Sparky in the picture solid mantle of Earth. below gets as low to Cool air sinks . the floor as possible?
Slide 37 / 107 Slide 38 / 107 Convection in Earth's Mantle Convection in Earth's Mantle Follow the arrows above to track the convection in Earth's mantle. Outer Core As the substances get closer to the surface of Earth, they cool down, become more dense and what happens? Because the Outer Core of Earth is so hot, the material that is (Notice that the substances within the Earth have a circular motion.. close to that point will warm up. As it warms, it becomes less dense, not straight up and down!) causing it to rise closer to the surface. Slide 39 / 107 Slide 40 / 107 The Convection Current Continues 7 Which of the following statements best explains why plates move? This process will continue to repeat endlessly. The motion of these currents causes massive changes to the land above, which we will learn about the in the next section. Heat from the Sun provides the energy A for them to move. The ocean pushes on the plates B causing them to shift. Volcanoes flow over the land forcing C them to move. Heat in the mantle causes plates to D Core slide. Slide 41 / 107 Slide 42 / 107 9 Materials in Earth's mantle move in a circular direction. 8 Which statement is correct? True A Hot substances rise. False B Cold substances rise. C Materials with lower densities sink. D Materials with higher densities float.
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