Plate Tectonics Guide Study

Plate Tectonics Study Guide Structure of the Earth 1. Layers: Crust, Mantle, Outer core, Inner core 2. Thickness of each layer: Crust is thinnest, Mantle is thickest 3. Consistency of each layer: Crust is hard and rigid, Mantle is semisolid, outer core is liquid, inner core is solid Historical Context of Earth's Layers 4. Early 20th-century geologists used these to study Earth's interior structure. Seismic waves 5. The concept of plate tectonics emerged from observations of: Continental fit, fossils, mountains, earthquakes 6. Explain Alfred Wegener’s Theory including a timeline and evidences 250 million years ago Pangea supercontinent: all continents were attached and slowly moved apart over millions of years. He noticed coastlines of Africa and South America fit together, and evidence of same plant and animal fossils were found along coastlines of both continents. Mountain ranges on these continents also matched up 7. The study of Earth's layers has evolved with advancements in __technology_ 8. Understanding Earth's layers is essential for predicting: earthquakes, tsunamis, volcanic eruptions Evidence Supporting Plate Tectonics 9. Explain at least 4 evidences that support the theory of plate tectonics a. Fossil distribution across continents supports the idea of once-connected landmasses. b. Geological formations, such as mountain ranges, show continuity across separated continents. c. Seafloor spreading provides evidence of tectonic plate movement and the creation of new oceanic crust. d. Earthquake and volcanic activity patterns align with tectonic plate boundaries, indicating movement. e. Paleomagnetic studies reveal historical shifts in Earth's magnetic field, supporting plate movement. f. Satellite measurements allow for precise tracking of plate movements and interactions. Modern Understanding of Plate Tectonics 10. The lithosphere is divided into tectonic plates that float on the semi-fluid _asthenosphere 11. Plate movements are driven by _convection currents_______ in the mantle 12. Understanding plate boundaries is crucial for predicting earthquakes, tsunamis, volcanic eruptions Overview of Crust Types Continental vs. Oceanic Crust (compare and contrast) 13. Thickness: Continental is 10x thicker than oceanic. Continental 20-40 mi and oceanic 4-6 mi 14. Age: Continental over 4 billion years old and oceanic crust is only 200 million years old Why are the ages of continental and oceanic plates so different? oceanic crust get subducted and destroyed often while continental does not. Oceanic has to replenish itself through seafloor spreading 15. Density: oceanic crust is denser, that's why it is subducted under continental Tectonic Plate Boundaries Types of Plate Boundaries and what they cause 16. Divergent Boundaries: Plates move apart: creates ridges and rifts from magma oozing up from mantle to fill space between plates 17. Convergent Boundaries: Plates move together: creates trenches when ocean subducts continental, tsunamis from earthquakes, island arcs from oceanic subducting oceanic, and mountains when continentals collide together 18. Transform Boundaries: Plates move past each other: creates earthquakes Convergent Boundaries 19. List and describe the 3 types of convergent boundaries oceanic/oceanic: older oceanic subducts under newer oceanic plates creating island arcs oceanic/continental: oceanic subducts under continental forming trenches and volcanoes on continent continental/continental: two continental plates collide and buckle up forming mountains 20. Subduction Zones: Subduction zones lead to: island arcs, trenches, and volcanoes 21. Volcanic Arcs: arc shaped set of volcanic islands formed from oceanic/oceanic plate collision Example of volcanic arcs: mariana islands and aleutian islands Mountain Formation 22. Explain how mountains are formed Two continental plates collide and buckle upwards 23. Give an example of a Mountain Range and specific peak Himalayas: mount everest What is happening to this mountain every year and why? Growing nearly an inch each year because the plates are still moving towards each other Geological Phenomena Associated with Plate Movement Volcanic Activity 24. Types of Eruptions: Effusive and explosive Why are the eruptions different? Pressure, Rate of degassing and viscosity of magma. High levels of these lead to explosive eruptions. 25. Impact of Eruptions: Danger to communities Earthquakes and Tsunamis 26. Tsunami Formation: Caused by large underwater earthquakes 27. Historical Example: Asian Tsunami, which killed more than 200,000 people in 11 countries across the Indian Ocean region in December 2004. Importance of Understanding Plate Boundaries Human Impact and Safety (Know the following:) ● ● ● ● ● . Predicting Geological Events: Knowledge of plate boundaries allows scientists to predict potential volcanic eruptions and earthquakes. Urban Planning: Cities located near tectonic boundaries can implement building codes and emergency plans to mitigate risks. Environmental Awareness: Understanding geological processes helps in conservation efforts and managing natural resources. Educational Initiatives: Programs like the American Museum of Natural History's interactive game enhance public understanding of tectonic movements. Global Collaboration: International cooperation is essential for monitoring seismic activity and sharing data to improve safety measures.