Interior of the earth

this work done by part of b.ed course

1. Presented by SARUKRISHNA V M B.Ed GEOGRAPHY

2. EARTH’S INTERIOR Knowledge is limited Temperature and pressure increase with depth. Depth of mine – 9 km only Depth of magma chamber – 64 km only Analysis on the basis of seismic waves

3. Earthquake waves Primary waves – moves fast through solid and slow through liquid Secondary waves – moves only through solid

4. Magma chamber Magma chamber

5. LAYERS OF EARTH 1. Crust 2. Mantle 3. Core

6. CRUST Outer most layer. Divided into 2 sub- layers Sial - ocean crust Sima - continental crust. Age – 4500million years ago. Sima – 3600 million years. Sial – 200 million years. Depth up to 40 km . Average density 2.9 g/cm 3

7. SIAL- The Oceanic Crust Si – silicon and Al – aluminum. High density. Iron and calcium are also present. Younger part of crust – 200 million years old.

8. SIMA – The Continental Crust Si – silicon and Ma – Magnesium. Low density. Aluminum, potassium, and sodium. Older part of the crust – 3600 million years.

9. 2 layers Of Crust Oceanic crust or Sial (very dense, made of basalt) Continental crust or Sima (less dense, made of granite)

10. CRUST- Points to remember Outer most layer Sub divisions – sial and sima Sial – oceanic crust- very dense – younger in age Sima - continental crust- less dense – older in age Mantle forms the second layer

11. MANTLE second layer of the interior of the earth. Two sub - layers – 1. Upper mantle. 2. Lower mantle. Thickness varies between 35km – 2900 km. Average density is 4.5 g/cm 3 Upper portion of mantle and crust together known as Lithosphere. lower mantle – Aesthenosphere.

12. UPPER MANTLE Solid in state. Thickness – 40 – 400km. Lithosphere About 100km Broken into plates Seven major plates and 12 minor plates. Aesthenosphere High temperature. Melting of rocks Convectional currents

13. LOWER MANTLE Molten in stage. Thickness- 400km 2900 km. Also known as mesosphere. Lies below the Aesthenosphere

14. MANTLE Upper mantle Lower mantle

15. Mantle – points to remember Second layer of the earth Divide into two - upper mantle and lower mantle Upper mantel and crust forms lithosphere. Convectional currents are found in Aesthenosphere Core forms the third layer

16. CORE Third layer of the earth. Formed by nickel and iron. Also called as Nife Nife – Ni - nickel and Fe – ferrous or iron Two parts 1 . Outer core. 2. Inner core. Temperature is 11000˚ C. Inner core is in solid state.

17. CORE – divided in two layers 1. Inner core Molten in stage Depth varies from 2900km – 5150 km. Density – 10.7 g/cm 3. 2. Outer core Solid in state High temperature High pressure Depth varies from – 5150 km – 6371 km. Density – 15 g/cm 3

18. Core Two layers 1.Outer core 2. Inner core

19. Core – points to remember Third layer of earth. Dived into two – inner and outer core. Outer core – molten in stage Inner core solid un sate. High temperature and pressure

20. EARTH AND EGG !!!!!! shell Yolk Egg white SHELL – CRUST EGG WHITE – MANTLE EGG YOLK - CORE

21. Summary table Name of the layer Subdivision thickness density Temperature CRUST Sial Sima 8 – 40 km 16 km 2.8 g/cc 2.9 g/cc Increase at a rate of 1˚C/ 32 m MANTLE Upper mantle Lower mantle About 100 km About 2800 km 3- 11 g/cc 2200 ˚C (approximately) CORE Outer Core Inner Core About 2150 km About 1255km 11 – 10 g/cc 5000˚ C ( approximately)

22. ASSIGNMENTS Prepare a summary table for three layers of the earth. Draw a neat diagram showing layers of the earth.