COURSE: GEOMORPHOLOGY-ORIGINAND EVOLUTION OF EARTH AND RELATED THEORIES LESSON: INTERIOR OF EARTH PRESENTED BY BHUMIKA SAINI
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INTERIOR OF THE EARTH The configuration of the surface of the earth is largely a product of the processes operating in the interior of the earth Exogenic as well as endogenic processes are constantly shaping the landscape. Exc genic as well as endogenic processes are constantly shaping the landscape. Understanding of the earth's interior is essential to understand the nature of changes that take place over and below the earth's surface. To understand geophysical phenomenon like volcanism, earthquakes etc . To understand the internal structure of various solar system objects To understand the evolution and present composition of atmosphere Future deep-sea mineral exploration etc.
SOURCES TO STUDY EARTH'S INTERIOR Sources Direct Indirect Temperature Mining and drilling Volcanic eruption and pressure variation Seismicity Meteors
EARTH'S LAYERS Earth's layers are identified by studying various direct and indirect sources The structure of the earth's interior is made up of several concentric layers. crust mantle core
EARTH'S LAYERS Exosphere here Not to Mesosphere scale Mesosphere cale Stratosphere Troposphere Crust Upper Mantle Mantle Outer Core Inner Core To scale
EARTH'S LAYERS- THE CRUST Crust is the outer thin layer with a total thickness normally be The thickness of the crust varies under the oceanic and continental areas. Oceanic crust is thinner (5-30 km thick)as compared to the continental crust(50- Crust is the outer thin layer with a total thickness normally between30-50 knm 0 km. 70 km thick). The continental crust is thicker in the areas of major mountain systems. It is as much as 70 -100 km thick in the Himalayan region. It forms 0.5-1.0 per centof the earth's volume. Mohorovicie (Moho) discontinuity forms the boundary between crust and . asthenosphere.
. The outer covering of the crust is of sedimentary material granitic rocks) and below that lie crystalline, igneous and metamorphic rocks which are acidic in nature. The lower layer of the crust consists of basaltic and ultra-basic rocks. The continents are composed of lighter silicates-silica aluminium (also called 'sial') while the oceans have the heavier silicates-silica magnesium (also called sima) Crust 0-100 km tcrust and upper most solid mantie) thick Mantle Mantle Crust Liquid Outer Core 100 k Inner Solid Not to scale 6378 km
EARTH'S LAYERS- MANTLE The mantle extends from Moho's discontinuity(35 km) to a depth of 2,900 km (Moho- Discontinuity to the outer core) .The crust and the uppermost part of the mantle are called lithosphere. Its thickness ranges from 10-200 km. . The lower mantle extends beyond the asthenosphere. It is in solid state. Lihosphere fcrust and upper most sold mantle) Crust 0-100 km Mantle The density of mantle varies between 2.9 and 3.3. . The density ranges from 3.3 to 5.7 in the lower part. It is composed of solid rock and magma . It forms 83 per cent of the earth's volume . The outer laver of the mantle is partly simatic while the inner laver is composed r Liquid Outer Core Solid Not to scale 6318 km Wheoloutserlayec utha asid rockartly simatic while the inner layer is composed wholly simatic ultra-basic roc
EARTH'S LAYERS- ASTHENOSPHERE The upper portion of the mantle is called asthenosphere. It is considered to be extending up to 400 km. e It is the main source of magma that finds its way to the surface during volcanic eruptions. It has a density higher than the crust's. Cust 0 100 km (crust and upper- most solid mantle) Mante Mantle Crust Liqad Outer Core Inner Solid Not to scale 6378 km scale
EARTH'S CHEMICAL COMPOSITION Concentration of Elements on Lunar Highlands, Lunar Lowlands, and Earth Hydrogen Titanium Magnesiumm Potassium Sodium Calcium Iron Aluminum Silicon Oxygen Earth Lunar Lowland Lunar Highland 10 20 30 40 50 Concentration ()
B Tech from MNIT, Jaipur. Appeared in CSE interview thrice. Loves teaching and playing badminton.