Name:____________________________________________________Date:_____________Pd Study Guide: Layers of the Earth, Continental Drift, and Plate Tectonics (S6E5a., S6E5e., S6E5f., and S6E5g.) 1.List and describe (composition) the layers of the Earth starting from the outermost layer. 1.crust (oceanic -more dense/thinner) and continental (thicker) 2.mantle (most of Earth’s Mass) (lithosphere, asthenosphere, mesosphere), 3.outer core 4. inner core 1. Crust 2. Lithosphere (Tectonic Plates)- Crust and rigid upper mantle 3. Asthenosphere (Convection Currents-caused by heat from the core) 4. Mesosphere (Lower Mantle) 5.Outer Core (Liquid Metal- iron and nickel) 6. Inner Core (Solid Metal-iron and nickel) Scientists know about Earth’s interior from studying seismic waves generated by earthquakes. 2. What is the inner core’s material? 3. What happens to the temperature, density, and pressure when you descend from the crust to the inner core? 4. List the layers from the least dense to most dense. 5. What is the Continental Drift Theory and who proposed the theory? 6. Describe 5 key pieces of evidence that Wegener discovered to support his theory of Continental Drift. Solid Iron and nickel They increase Crust, mantle, outer core and inner core Theory that was proposed by Alfred Wegener that stated that the continents were in one large landmass called Pangaea and drifted apart over time --mesosaurus (fossils) on different continents (too small to swim in the ocean) --tropical plant fossils found in artic regions --coastlines of the continents fit together like puzzle pieces --mountain ranges on different continents lineup --coal found in artic regions --glacial grooves found in rocks in warm climates **The theory was rejected because Wegener could NOT explain how the continents moved* 7. What was the name of the supercontinent proposed by Wegener? What Pangaea- “all Lands” or “all Earth” does the name mean? 8. What is the midocean ridge? What type of plate boundary movement exists at the mid-ocean ridge? What type of crust forms at the mid-ocean ridge? 9. Describe the process of sea-floor spreading. Where does the sea floor spread? 10. Describe the process of subduction. What is a deep ocean trench? 11. What is the plate tectonic theory? What are tectonic plates? 12. What is the driving force that moves the tectonic/lithosp heric plates? Where does this occur? 13. Where does -Longest chain of underwater volcanic mountains in the world -Mid-Ocean Ridge forms at divergent plate boundary movement -new oceanic crust forms at the Mid-Ocean Ridge (New sea floor) Sea-floor spreading happens at the Mid-Ocean Ridge (divergent plate boundary) Process where new oceanic crust forms, when magma is Heated in the asthenosphere( it becomes less dense) , and rises Creating new oceanic crust. (Older crust is pushed farther away from the ridge.) When two plates(oceanic-oceanic or continental-oceanic) collide (converge) together the most dense (oceanic plate) plate is subducted (sinks) back into the asthenosphere and melts Deep ocean trenches are huge cracks in the deep-ocean basin. They form where one oceanic plate is pushed beneath a continental plate or another oceanic plate at the subduction zone. The theory that states Earth’s lithosphere is divided into tectonic plates that float or move on top of the asthenosphere- (convection currents in the asthenosphere cause this to occur) Tectonic plate-pieces of the lithosphere (crust + upper mantle) that constantly move over Earth’s surface. Convection currents in the Earth’s asthenosphere is the driving force that moves the tectonic plates Convention-heat rises from the core and creates a difference in density in the material in the asthenosphere which causes the material to circulate. Occurs in the asthenosphere. Along the boundaries of tectonic plates most tectonic activity (earthquakes, volcanic eruptions, mountains, volcanic eruptions) occur? 14. Describe what occurs at continentaloceanic convergent boundary? --the more dense oceanic crust will sink (subduct) beneath the continental crust Landforms: volcanoes, trenches Geological events: volcanic eruptions, earthquakes (Subduction Zones) 15. What are volcanic mountains, how do they form, and where do they form? 16. Describe what occurs at a continentalcontinental convergent boundary? 17. What are folded mountains, how do they form, and where do they form? 18. What landforms could be created at convergent boundary? --rock that is melted in subduction zones form magma, which rises to the Earth’s surface and erupts to form volcanic mountains. Volcanic mountains can also form under sea. These mountains form at an oceanic-continental convergent boundary. 19. Describe what occurs at an oceanicoceanic convergent boundary? 20. What is a fault? Along what type of plate boundary do most faults form? What type of geological events occur along faults? 21. Describe how the plates moves at each of the following boundaries: convergent, divergent, and transform 22. What is the Ring of Fire? What are Hot Spots? --the more dense oceanic crust will sink (subduct) beneath the other plate-deep Ocean trenches can form. What happens to the oceanic crust that gets subducted? It gets melted in the Asthenosphere- What force pulls the plate down into the asthenosphere? Gravity --both plates will collide, buckle and thicken Landforms: folded mountains Geological events: earthquakes --formed when rock layers (continental crust) are squeezed together (compression) and pushed upward and form mountains. --they form at a convergent boundary Folded mountain ranges are the highest mountain ranges in the world. Ex. Himalayan Mts. -Continental -Continental convergent- folded mountains Continental- Oceanic Convergent- volcanoes and trenches (Subduction Zones) Oceanic-Oceanic Convergent- Ocean trenches, Volcanic Islands (Subduction Zones) A fault is a break in the Earth’s Crust Most faults occurs along transform boundaries Earthquakes occur along faults Convergent – plates come together. Divergent – plates move apart. Transforms – plates slip past each other horizontally It includes the plate boundaries surrounding the Pacific Ocean where there are lots of volcanoes. Hot spots – volcanically active places on the Earth’s surface that are far from plate boundaries.