INTERIOR OF THE EARTH WITH MCQ's
INTERIOR OF THE EARTH WITH MCQ's
Introduction
Introduction
Our living planet Earth is the only place where human habitations are taken place and it is possible due to the present of the atmosphere which makes it unique from the other planets or we can also say others heavenly bodies. This entire phenomenon is proved by the scientists under their keen interest using different advanced technological tools. But have we thought about what’s going on inside of the earth? As we know that there are very little knowledge about the inside of the earth if we compared it to the earth’s atmosphere and the knowledge acquired by the scientists through different sources or we can say assumptions because there is no possible of direct observation. Now this article give you some basic idea and knowledge about the interior of the earth.
Prediction/Sources of the study
The prediction of the study of the interior of the earth divided into two parts-
A) Direct Prediction
a) Surface rocks
b) Volcanic eruptions
c) Mining etc.
B) Indirect Prediction
a) Earth's temperature and pressure
b) Fossil Fuel
c) Earth's gravity
d) Magnetic sources
e) Meteors
f) Earthquake waves etc.
Elements
The interior of the earth is made up with the following important elements. They are-
a) Iron(Fe)
b) Magnesium (mg)
c) Aluminium(Al)
d) Oxygen (O)
e) Silicon (Si)
f) Silicate Compounds
Structure of the interior of the earth
The interior of the earth further split up into three parts i.e.-
1) CRUST(sial)
2) MANTLE (sima)
3) CORE(nife)
Australian Geologist Suess, divide the earth's interior into three parts i.e- sial, sima and nife respectively.
1) CRUST
Followings are the important characteristics of Earth crust i.e.-
Thickness:
The crust is the thinnest and outermost part of the part where human habitations are taken place. It's thickness is not constant and is varies from ocean to land from 8 to 40 km.
Discontinuities: In simply, Discontinuities are the transition zones that separates or divides the whole system or part or we can say lack of continuity. Connard Discontinuity divides the earth's upper crust and lower crust and Mohorovicic Discontinuity divide the entire crust from mantle. Andrija Mohorovicic, Croatian Geophysicist firth discovered the seismic or Moho Discontinuity in 1909.
Forming Elements:
The earth's crust is formed from two minerals i.e- silica and aluminium. Hence, this layer is also known as SIAL (silica and aluminium).
Density:
The average Density of the earth's crust 2.7 gm/cm3
Temperature:
The crust temperature is not fixed and is varies from depth. The temperature is increased with the increasing with depth and ranges from 5000C to 10000C
Pressure:
Pressure also increases with the increases with depth it's due to the overburden of the underlying rocks.
Types:
The crust is further divided into two parts i.e. continental crust and oceanic crust (both have are further divided into two parts upper and lower crust). Continental crust is thicker as compared to the oceanic crust.
2) MANTLE
Thickness:
If we see in terms of location and density then it is the intermediate layer of the earth. The thickness of this layer is about 2900 km.
Discontinuities:
Repetti Discontinuity divides the earth's upper mantle and lower mantle and Gutenberg Discontinuity divide the entire mantle from the core and here the earth's velocity and density of p-waves increases.
Forming Elements:
The earth's mantle is formed from two minerals i.e- silica and Magnesium. Hence, this layer is also known as SIMA (silica and magnesium).
Temperature:
In mantle temperature ranges from 500 to 9000C.
Density:
The average Density of the earth's mantle 5.5 gm/cm3
Low velocity zone:
The mantle's asthenosphere is considered as low velocity zone it's due to the velocity of the earthquake waves decreases(s-waves, 100 to 200 km depth).
Mantle transition zone:
The region between 400 to 670 km is known as Mantle transition zone.
Types:
The mantle is divided into two parts upper mantle and lower mantle. The upper mantle is also called as Asthenosphere, which thickness is about 250 km.
3) CORE
Thickness:
The core is the innermost layer of the earth and it's thickness is about 3500 km in radius.
Discontinuities:
Lehman Discontinuity divides the earth's upper from the earth's lower core.
Forming Elements:
The earth's mantle is formed from two minerals i.e- nickel and iron. Hence, this layer is also known as NIFE (nickel and iron).
Temperature:
The temperature of the core is ranges from 2200 to 27500C.
Pressure:
The average Density of the earth's core is 17.2 gm/cm3. 5.5 gm/cm3 is considered as the earth's average Density.
Types:
The mantle is divided into two parts upper core and lower core. The upper core is assumed to have the properties is in liquid state and the lower core is in solid state.
Thus, the interior of the earth constitutes crust 1%, mantle 85% and core 14% respectively.
MCQ'S ON THE INTERIOR OF THE EARTH
1) Density of the core is highest because-
a) due to heavy pressure of overlying rocks
b) due to heavy temperature of overlying rocks
c) due to heavy density of overlying rocks
d) none of the above
Ans- a
2) The average density of the earth is-
a) 2.3 gm/cm3
b) 5.5 gm/cm3
c) 17.2 gm/cm3
d) 6.5 gm/cm3
Ans- b
3) Who discovered the core-
a) Harold Jeffreys
b) R.D Oldham
c) Inge Lehman
d) none of the above
Ans- b
4) The inner core is solid first proved by-
a) Inge Lehman
b) Suess
c) Cavendish
d) R.D Oldham
Ans- a
5) The source of the Earth's magnetic field is-
a) outer mantle
b) liquid outer core
c) lower crust
d) outer crust
Ans- b
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