1. The Theory of Plate Tectonics Chapter 11

2. https://www.youtube.com/watch?v=lWUQxr5MBvc&list=PLBHpYpFt0e58G qQ48Ub8N8V4VlbH9oGbG https://www.youtube.com/watch?v=lWUQxr5MBvc&list=PLBHpYpFt0e58G qQ48Ub8N8V4VlbH9oGbG https://www.youtube.com/watch?v=lJiAUvB1vEU

3. The Earth Inside and Out

4. Inner core = mostly iron nickel with some other heavy elements (5000 degrees Celsius and solid) Outer Core= Same elements and temperature but lower pressure makes it liquid (thermal plumes) Mantle= mostly silicone and oxygen (SiO2 and SiO4) with some iron and magnesium. Divided into upper mantle (lithosphere + asthenosphere) Solid, but due to extreme temperature rocks behaves with fluid properties, like hot glass, “plasticity”

5. The Earth Inside and Out Crust= mainly oxygen and silicon, with magnesium and iron. Lithosphere includes upper most rigid part of the mantle and the crust Scientists distinguish between upper mantle and the crust because of certain elemental composition changes Mantle contains more iron and magnesium, making the rocks denser and heavier. Felsic (continental crust), Mafic (oceanic crusts), Ultra Mafic (mostly asthenosphere)

6. Rock Cycle

8. Isostatic Equilibrium Isostatic Equilibrium: https://www.youtube.com/watch?v=_eDYKA49uHUhttps://www.youtube.com/watch?v=_eDYKA49uHU Definition: the balance between the weight of the crust and the buoyancy provided by the mantle. Oceanic crust (denser, colder, deposition of sediment and volcanic activity) Continental crust (warmer, less dense, + erosion) Reason why mountains have “Roots”

9. Alfred Wegner and Continental Drift https://www.youtube.com/watch?v=MEh4B1Pv8YE Pangaea + Panthalassa Laurasia + Gondwanaland

10. New Technology and Seafloor Knowledge Using an Echo-Sounder, the German Meteor expedition mapped the contours and depths of the South Atlantic 1940, Hugo Benioff, seismology and Ring of Fire. Mid-ocean Ridges, trenches, and Rift valleys.

11. New Technology and Seafloor Knowledge

12. The Creation and Destruction of Seafloor Mid-Ocean Ridge = Seafloor being created at Rift Valleys Trenches = Subduction (Seafloor Destruction) Average age of oceanic crusts is estimated to be between 180-200 million years Occurs at a rate similar to the growth of finger nails

13. The Creation and Destruction of Seafloor

14. Evidence of Seafloor Spreading 3 Forms of Evidence for Seafloor Spreading: Sediment layers are thin or absent at ridges and grow thicker as you move away, which makes sense since the oldest seafloor would have accumulated more sediment over time. 2 nd Radiometric Dating: based on known decay rates of unstable elements in rocks, absolute dating is possible. Scientists found seafloor to be significantly younger than continental rock, as well as younger rock the closer you are to ridges. Magnetometer data (measures polar orientation), symmetrical pattern in polar orientation of magnetism of seafloor basalt rock. https://www.youtube.com/watch?v=GyMLlLxbfa4&list=PLEB319590CD49830D

15. 1963 Fred Vines and Drummond Matthews

16. The Unifying Theory: Plate Tectonics (Seafloor Spreading and Cont Drift Combined) Earth’s lithosphere is composed of plates (some only oceanic crust, some continental, some both) They move by cm per year, powered by convection (maybe), as well as slab pull (from subduction zones) and slab push (from elevated rift) As plates move they form convergent, divergent, and transform boundaries. Divergent = seafloor spreading (rift valleys) Volcanic activity at divergent boundary may build mountains (possibly Iceland)

17. Divergent Boundary

18. The Unifying Theory: Plate Tectonics (Seafloor Spreading and Cont Drift Combined) Convergent = subduction (seafloor destruction at Trenches) One plate is subducted (sinks beneath) the other Can result in volcanic island arc (like Japan) along oceanic to oceanic plate boundary https://www.youtube.com/watch?v=JPmZLM5R3ME Volcanic mountain range produced along continental to oceanic plate boundary (Ring of fire, Andes mountains ect) Continental to continental convergent boundary = crust folding and mountain formation (Himalayas) https://www.youtube.com/watch?v=d9bKXY0OMxc&ebc=ANyPxKpIZa8fENVq5TE 2drA7dE3cZyj4npEWdmma6UVsL3x6WfvkwBIGZwOnP3P1cz1d5c4FCXVxVGfWE4 hfByn2861Z8kreQQ https://www.youtube.com/watch?v=d9bKXY0OMxc&ebc=ANyPxKpIZa8fENVq5TE 2drA7dE3cZyj4npEWdmma6UVsL3x6WfvkwBIGZwOnP3P1cz1d5c4FCXVxVGfWE4 hfByn2861Z8kreQQ

19. Oceanic - Oceanic

20. Oceanic - Continental

21. Continental - Continental

22. Transform AKA Fault Boundary San Andreas Fault Plates slide past each other Boundary between Pacific and North American Plate Basin and Range formation: https://www.youtube.com/watch?v=S2Idwc NHa4s https://www.youtube.com/watch?v=S2Idwc NHa4s

23. San Andreas Fault Boundary

24. Hot Spots Small melting areas within mantle, where thermal plumes cause magma to push up intensely eventually breaking through the crust Can occur at plate boundaries but further from the edge (Yellowstone national park) Hot spots do not move with plates since the originate from asthenosphere, resulting in rows of volcanic formations (Hawaiian Islands)

25. Hot Spots

26. Plate Movement Driving Forces Convection (questionable) Seafloor Spreading Plates pushing into, or past each other Slab Pull

28. New Explanation for Seafloor Spreading and Plate Tectonics 21st Century Earth Dynamics Part 1: https://www.youtube.com/watch?v=jWUbj-VRwPk https://www.youtube.com/watch?v=jWUbj-VRwPk 21st Century Earth Dynamics Part2: https://www.youtube.com/watch?v=oAN0asAv62Q&ebc=ANyPxKqpcNDZe lNVIJCuipbVjdJH88TlpFg7TQOYdqhFfW9ffAZ0llMmwPZ_VuDg2dm68T5V OW99vw-BtEcFsUyh4BKxxwVVMw https://www.youtube.com/watch?v=oAN0asAv62Q&ebc=ANyPxKqpcNDZe lNVIJCuipbVjdJH88TlpFg7TQOYdqhFfW9ffAZ0llMmwPZ_VuDg2dm68T5V OW99vw-BtEcFsUyh4BKxxwVVMw