Sci 10 L. seafloor spreading seafloor.pptx

This file explains Sea floor spreading. It is explained in this file.

1. is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.

2. First proposed in the early 1960s by the American geologist Harry H. Hess, its major tenets gave great support to the theory of continental drift and provided a conceptual base for the development of plate tectonics. 

3. Supporting Evidence for Seafloor Spreading T he rock making up the ocean floor is considerably younger than the continents. For example, the Red Sea was created as the African plate and the Arabian plate moved away from each other.

4. Supporting Evidence for Seafloor Spreading Seafloor spreading is also pulling the continents of Australia, South America, and Antarctica away from each other in the East Pacific Rise.

5. Supporting Evidence for Seafloor Spreading Seafloor spreading is also pulling the continents of Australia, South America, and Antarctica away from each other in the East Pacific Rise.

6. Findings that support Seafloor Spreading Theory: 1. Rocks are younger at the mid-ocean ridge. 2. Rocks far from the mid-ocean ridge are older. 3. Sediments are thinner at the ridge. 4. Rocks at the ocean floor are younger than those at the continents.

7. Q22. What do the stripes in the paper represent? Answer: The stripes represent the rocks with normal and reverse polarities.

8. Q23. What does the middle slit represent? What occurs in this region? Answer: The middle split represents the mi d - ocean ridge. In this region, the seafloor spreading occurs.

9. Q24. What is the role of the mid- ocean ridge in the movement of lithospheric plates? Answer: The role of the mid-ocean ridge in the movement of lithospheric plates is that it is where the forces that pushes the lithosphere came from.

10. Q25. How does the new seafloor form at the mid-ocean ridge? Answer:The hot and less dense material below the Earth’s crust rises towards the mid-ocean ridge. This materials flows sideways carrying the seafloor away from the ridge, and creates a crack in the crust. The magma flows out of the crack, cools down and create a new seafloor.

11. Q26. What process/es happen at the side slits? The side slits is where subduction occurs.

12. Q27. Is the Earth getting larger and wider when plates drif t away from each other? Explain briefly. Answer: The Earth is not getting larger and wider when plates drift away from each other because if a new seafloor was created, the old one was destructed.

13. The rate of formation of a new seafloor is not always as fast as the destruction of the old seafloor at the subduction zone. This explains why the Pacific Ocean is getting smaller and why the Atlantic Ocean is getting wider.

14. Terms to look out for! Mantle fumes Hotspot Hotspot volcano Hotspot track Paleomagnetism