Layers of the earthooooooooooooooww.pptx

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1. Layers of the earth

2. Objective The learners demonstrate an understanding of the Earth’s internal structure.

3. review Name important earth scientists and their important contributions in the understanding of the Earth’s System .

4. Video Presentation

5. The Earth consists of four concentric layers: inner core , outer core , mantle and crust . The crust is made up of tectonic plates, which are in constant motion.

6. Earthquakes and volcanoes are most likely to occur at plate boundaries.

7. The structure of the Earth The Earth is made up of four distinct layers:

8. 1. The inner core is in the centre and is the hottest part of the Earth. It is solid and made up of iron and nickel with temperatures of up to 5,500°C. With its immense heat energy, the inner core is like the engine room of the Earth.

9. 2. The outer core is the layer surrounding the inner core. It is a liquid layer, also made up of iron and nickel. It is still extremely hot, with temperatures similar to the inner core. The transition period between outer core and inner core is called Lehmann Discontinuity. Named after by Inge Lehmann.

10. 3. The mantle T he widest section of the Earth. It has a thickness of approximately 2,900 km . The mantle is made up of semi-molten rock called magma. In the upper parts of the mantle the rock is hard, but lower down the rock is soft and beginning to melt.

11. The upper mantle has with it a soft weak layer called ASTHENOSPHERE, which is capable flowing. This property facilitates the movement of the lithospheric plates.

12. The boundary between the mantle and outer core is called GUTENBERG DISCONTINUITY. Named after by Beno Gutenberg.

13. 4. The crust T he outer layer of the earth . It is a thin layer between 0-60 km thick . The crust is the solid rock layer upon which we live.

14. There are two different types of crust: continental crust , which carries land, and oceanic crust, which carries water . The boundary that separates the crust and mantle is called MOHOROVICIC DISCONTINUITY . Named after by Andrija Mohorovicic .

15. Elements present are: Fe (Iron), Ca (Calciu m ), H (Hydrogen), Al (), Si (Silicon), O (Oxygen), Na (Sodium), K ( Potasium ) and Ti (Titanium).

16. Thank you!