1. Presentation on ThePresentation on The
surface and Interior of thesurface and Interior of the
EarthEarth
By Anurag bhardwajBy Anurag bhardwaj
Standard 7Standard 7thth
A3A3
In the Guidence of Mam LazzIn the Guidence of Mam Lazz
RaniRani

2. The Interior of the EarthThe Interior of the Earth
 The interior The interior structure of thestructure of the
EarthEarth is layered in spherical shells, is layered in spherical shells,
like an onion. These layers can belike an onion. These layers can be
defined by either their defined by either their chemicalchemical or or
their their rheologicalrheological properties. properties. EarthEarth has has
an outeran outersilicatesilicate solid solid crustcrust, a highly , a highly
viscousviscous mantlemantle, a liquid , a liquid outer coreouter core that that
is much less viscous than the mantle,is much less viscous than the mantle,
and a solid and a solid inner coreinner core. Scientific. Scientific
understanding of Earth's internalunderstanding of Earth's internal
structure is based on observations of structure is based on observations of
topographytopography and bathymetry, and bathymetry,
observations of rock in outcrop,observations of rock in outcrop,
samples brought to the surface fromsamples brought to the surface from
greater depths by volcanic activity,greater depths by volcanic activity,
analysis of theseismic waves that passanalysis of theseismic waves that pass
through Earth, measurements ofthrough Earth, measurements of
the gravity field of Earth, andthe gravity field of Earth, and
experiments with crystalline solids atexperiments with crystalline solids at
pressures and temperaturespressures and temperatures
characteristic of Earth's deep interior.characteristic of Earth's deep interior.

3. CrustCrust
 In geology, the crust is the outermost solid shell of aIn geology, the crust is the outermost solid shell of a
rocky planet or natural satellite, which is chemicallyrocky planet or natural satellite, which is chemically
distinct from the underlying mantle. The crusts of Earth,distinct from the underlying mantle. The crusts of Earth,
our Moon, Mercury, Venus, Mars, Io, and other planetaryour Moon, Mercury, Venus, Mars, Io, and other planetary
bodies have been generated largely by igneousbodies have been generated largely by igneous
processes, and these crusts are richer in incompatibleprocesses, and these crusts are richer in incompatible
elements than their respective mantles.elements than their respective mantles.

4. MantleMantle
 The mantle is a part of a terrestrial planet or other rocky body large enough to have differentiationThe mantle is a part of a terrestrial planet or other rocky body large enough to have differentiation
by density. The interior of the Earth, similar to the other terrestrial planets, is chemically dividedby density. The interior of the Earth, similar to the other terrestrial planets, is chemically divided
into layers. The mantle is a highly viscous layer between the crust and the outer core. Earth'sinto layers. The mantle is a highly viscous layer between the crust and the outer core. Earth's
mantle is a rocky shell about 2,900 km (1,800 mi) thick[1] that constitutes about 84% of Earth'smantle is a rocky shell about 2,900 km (1,800 mi) thick[1] that constitutes about 84% of Earth's
volume.[2] It is predominantly solid and encloses the hot core rich in iron and nickel, whichvolume.[2] It is predominantly solid and encloses the hot core rich in iron and nickel, which
occupies about 15% of Earth's volume.[2][3] Past episodes of melting and volcanism at theoccupies about 15% of Earth's volume.[2][3] Past episodes of melting and volcanism at the
shallower levels of the mantle have produced a thin crust of crystallized melt products near theshallower levels of the mantle have produced a thin crust of crystallized melt products near the
surface, upon which we live.[4] Information about structure and composition of the mantle eithersurface, upon which we live.[4] Information about structure and composition of the mantle either
result from geophysical investigation or from direct geoscientific analyses on Earth mantleresult from geophysical investigation or from direct geoscientific analyses on Earth mantle
derived xenoliths.derived xenoliths.

5. Inner CoreInner Core
 The inner core of the Earth, itsThe inner core of the Earth, its
innermost part, is a primarilyinnermost part, is a primarily
solid ball with a radius of aboutsolid ball with a radius of about
1,220 km (760 mi), according1,220 km (760 mi), according
to seismological studies.[1][2]to seismological studies.[1][2]
(This is about 70% of the(This is about 70% of the
length of the Moon's radius.) Itlength of the Moon's radius.) It
is believed to consist primarilyis believed to consist primarily
of an iron–nickel alloy, and toof an iron–nickel alloy, and to
be about the samebe about the same
temperature as the surface oftemperature as the surface of
the Sun: approximately 5700 Kthe Sun: approximately 5700 K
(5430 °C).(5430 °C).

6. Outer CoreOuter Core
 The outer core of the Earth is aThe outer core of the Earth is a
liquid layer about 2,266 kmliquid layer about 2,266 km
(1,408 mi) thick composed of(1,408 mi) thick composed of
iron and nickel which liesiron and nickel which lies
above the Earth's solid innerabove the Earth's solid inner
core and below its mantle. Itscore and below its mantle. Its
outer boundary lies 2,890 kmouter boundary lies 2,890 km
(1,800 mi) beneath the Earth's(1,800 mi) beneath the Earth's
surface. The transitionsurface. The transition
between the inner core andbetween the inner core and
outer core is locatedouter core is located
approximately 5,150 km (3,200approximately 5,150 km (3,200
mi) beneath the Earth'smi) beneath the Earth's
surface.surface.

7. Rock CycleRock Cycle
 The rock cycle is a fundamental concept in geology that describes the dynamic transitionsThe rock cycle is a fundamental concept in geology that describes the dynamic transitions
through geologic time among the three main rock types: sedimentary, metamorphic, and igneous.through geologic time among the three main rock types: sedimentary, metamorphic, and igneous.
As the diagram to the right illustrates, each of the types of rocks are altered or destroyed when itAs the diagram to the right illustrates, each of the types of rocks are altered or destroyed when it
is forced out of its equilibrium conditions. An igneous rock such as basalt may break down andis forced out of its equilibrium conditions. An igneous rock such as basalt may break down and
dissolve when exposed to the atmosphere, or melt as it is subducted under a continent.dissolve when exposed to the atmosphere, or melt as it is subducted under a continent.
 A diagram of the rock cycle. Legend: 1 = magma; 2 = crystallization (freezing of rock); 3 =A diagram of the rock cycle. Legend: 1 = magma; 2 = crystallization (freezing of rock); 3 =
igneous rocks; 4 = erosion; 5 = sedimentation; 6 = sediments & sedimentary rocks; 7 = tectonicigneous rocks; 4 = erosion; 5 = sedimentation; 6 = sediments & sedimentary rocks; 7 = tectonic
burial and metamorphism; 8 = metamorphic rocks; 9 = melting.burial and metamorphism; 8 = metamorphic rocks; 9 = melting.

8. Minerals : IronMinerals : Iron
 Iron is a chemical element with the symbol Fe (from Latin: ferrum) and atomic numberIron is a chemical element with the symbol Fe (from Latin: ferrum) and atomic number
26. It is a metal in the first transition series. It is the most common element (by mass)26. It is a metal in the first transition series. It is the most common element (by mass)
forming the planet Earth as a whole, forming much of Earth's outer and inner core. Itforming the planet Earth as a whole, forming much of Earth's outer and inner core. It
is the fourth most common element in the Earth's crust. Iron's very common presenceis the fourth most common element in the Earth's crust. Iron's very common presence
in rocky planets like Earth is due to its abundant production as a result of fusion inin rocky planets like Earth is due to its abundant production as a result of fusion in
high-mass stars, where the production of nickel-56 (which decays to the mosthigh-mass stars, where the production of nickel-56 (which decays to the most
common isotope of iron) is the last nuclear fusion reaction that is exothermic. Thiscommon isotope of iron) is the last nuclear fusion reaction that is exothermic. This
causes radioactive nickel to become the last element to be produced before collapsecauses radioactive nickel to become the last element to be produced before collapse
of a supernova leads to the explosive events that scatter this precursor radionuclideof a supernova leads to the explosive events that scatter this precursor radionuclide
of iron abundantly into space.of iron abundantly into space.

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