EARTH'S STRUCTURE: INTERIOR OF THE EARTH

INTERIOR PART OF THE EARTH

INTRODUCTION

The interior of the earth made of number of layer.This layer is not homogeneous type.about three thousand years ago,SIR ISSAC NEWTON calculated the average density of the earth surface from his studies of planet and force of gravity .He concluded that earth surface made of lighter materials and center of the earth made of denser materials.the density of the earth and center are 2.8 g/cm 3 and 5.5 g/cm 3 respectively.

SOURCE OF INTERIOR OF THE EARTH

We know the radius of the earth is 6370 km.So it is possible to go center of the earth . but we able to know about the center through  drilling and mining.

there are two source that may us to understand about the interior of the earth i.e direct-source and indirect source 

• Direct source: The direct sources are such as earthquake,rocks,volcanic eruption etc.
• Indirect source: The indirect sources are such as the rate of change in temperature, meteorites, gravitation, magnetic sources, seismic waves etc.

STRUCTURE OF THE EARTH  

•  There are three layer of the earth i.e crust,mantle , core.

 CRUST: The outer layer of the earth surface.

1. It is almost 8 km to 40 km thick.sometimes it becomes 90 km where the young folded mountain are formed.
2. This layer is less dense and is consisted of lighter material such as silica and aluminium and magnesium.
3. Crust consists of of two part i.e Continental crust and oceanic crust. 
4. Continental crust are comparatively less dense than Oceanic crust.
5. Continental crust are floating on the oceanic crust.
6. The continental crust consists of silicon and aluminum so that this layer is called SIAL  
7. The density of the SIAL is 2.67 g/cm 3 .the sial is extended up to 5 km
8.  SIMA is located below the SIAL having density of 3 g/cm 3.
9. The sima is consisted of silicon and magnesium.
10. DISCONTINUITY: The rate of the wave direction is called discontinuity.
11. The discontinuity between the sial and sima is called CONRAD discontinuity.it was discovered by Conrad. 

     

ASTHENOSPHERE  is below part of SIMA.
it is thick 80 to 400 km, it is highly viscous ,weak and ductile in nature.all type of  plates floats here and main source of magma.

 MANTLE: This layer lies below asthenosphere, crust and upper part of the core.this layer is also called Mesosphere.

1. It is about 2900 km extended.
2. This layer consists of chromium,ferrous, aluminum, magnesium 
3. This layer is categorized by two part i.e Upper mantle which consists of chromium and ferrous,silicon and magnesium having density of 3.3 to 3.6 g/cm 3. 
4. The lower part of the mantle consists of nickle and ferrous silicon and magnesium.
5. The density id heaver than upper part i.e 4 g/cm3
6. The discontinuity between upper part and lower prt of the mantle is called Repitti discontinuity
7. The discontinuity between lithosphere and mesosphere is called Moho discontinuity according to name of scientist of Mohorovicic.

CORE: The center part of the earth.

1. Core is 6371 km thick and the density is very high 
2. The temperature of the core is 6000 degree centigrade.
3. This layer is consisted of nickle and ferrous.
4. The density of upper and lower core is 13.6 and 14.4 g/cm 3 respectively.
5. This layer is also called Barysphere
6. The discontinuity found in barysphere and mesosphere is Gutenberg discontinuity after the name of Gutenberg. 
7. The discontinuity found in the upper and the lower core is called Lehman discontinuity.

Thus we have seen three important parameter that plays a major role are pressure,density and temperature.and these three increases with depth of the earth.

Read More

• Share