EFFECTS OF PLATE TECTONICS – Edumatics Note Guide What are Tectonic Plates? alters, solid, asthenosphere, tectonic, surface 1. The most powerful force that _____________ Earth’s _____________ is the movement of the tectonic plates. 2. Tectonic plates are large, _______pieces of the earth’s lithosphere that move in different directions on top of a hotter flowing layer called the ___________________________. 3. There are 7 major ______________ plates and some minor ones that make up the surface of the Earth. Plate Tectonic Theory interior, earthquakes, Pangaea, age, moved, continental drift, geological, sea floor, ocean floor, new, midocean, plate tectonic, convection, older 4. In the early 1900’s, Alfred Wegener put forward the theory that the continents were once part of one large land mass called _____________. 5.His theory is called the ____________ __________ theory, and explained why identical animal fossils like that of the MESOSAURUS, were found on coastlines separated by vast oceans. It also explained why similar ____________features were found on coastlines, like the North American Appalachian Mountains lining up with mountains in Scotland and Scandinavia. 6. But this theory didn’t explain “why” the continents ________________. It is only with the ______________ _____________ explorations of the early 1960’s that the continental drift theory was verified. 7. These explorations led to the discovery of magma oozing up in the middle of underwater mountain chains, known as __________________ ridges, to create new ocean floor. This process was called __________________ __________________ spreading. 8. Sea floor spreading occurs when tectonic plates move __________ from each other and create a gap in the Earth’s crust. Magma rises up and fills this gap, creating ____________ oceanic crust. 9. The ___________ of the ocean floor is an important piece of evidence that supports sea floor spreading. New crust is found at the mid ocean ridges and gets progressively ______________ as it moves away from both sides of the ridge. 10. The continental drift theory and sea floor spreading, in addition to the discovery that ________________ and volcanoes occur most frequently at mid-ocean ridges and specific areas around the world, led to the development of a new unifying theory called the _______________ _______________ theory. 11. The plate tectonic theory explains how Earth works. Heat from Earth’s _______________, creates __________________ currents which move the lithospheric plates around in different directions, at different speeds. Divergent Plate Boundaries continental, rift, divergent, fault block, fault, away, new 12. A ______________ boundary is the place where two tectonic plates move ________________, or spread apart, from one another. The majority of divergent boundaries are located at mid-ocean ridges where sea floor spreading takes place and _____________ crust is formed. 13. A divergent boundary is also formed when two _______________ plates move apart; a _______________ develops on the Earth’s crust. 14. Some of the landforms on Earth are created by the movement of divergent plates that cause ________________ valleys and _____________ ____________ mountains. Convergent Plate Boundaries asthenopshere, subduction, convergent, increases, towards, oceanic, volcanoes, lighter, folded, denser, magma, Himalayas, trench 15. A __________________ boundary is a place where two tectonic plates move ___________, or push against each other. When 2 continental plates converge, they can squeeze together and force the crust upwards. 16. This leads to the formation of _______________ mountains. This is how the highest mountain range , the _______________, were formed. 17. When an _______________ plate converges with a continental plate, the ______________oceanic plate slides beneath the _________ continental plate, into the _____________. This region is called a ____________________ zone and the tectonic forces are so strong that a ________________ or crack can form in the ocean floor. 18. As the oceanic crust sinks downward toward the asthenosphere, the temperature ____________ and the edge of the oceanic plate melts to form _________. The magma can eventually erupt through Earth’s crust to form ___________________. Transform Plate Boundaries California, earthquakes, slide past, tectonics, fault 19. At transform boundaries, instead of moving towards or away from each other, tectonic plates ___________ _____________ one another. This kind of boundary results in a large _______________. An example of this is the San Andreas Fault in ________________________. 20. Because tectonic plates are not smooth, a lot of jolting and gnashing occurs while the plates slide past one another, creating _______________. 21. Plate ________________ has led to a sweeping change in our understanding of Earth and the forces that shape it.