This Presentaion will give us knowledge about our planet Earth..with regards to its Size, Shape, Inner Structure, Atmosphere Etc..
Hope you like it.. Enjoy Watching
3. Earth
is the third planet from
the Sun, and the densest
and fifth-largest of the
eight planets in the Solar
System. It is also the
largest of the Solar
System's four terrestrial
planets. It is sometimes
referred to as the
world, the Blue Planet,[20]
or by its Latin name, Terra
5. Shape and Size of the Earth
Eratosthenes became head librarian at the Royal
Library around 235 BC. There, he made the first
accurate measurement of the earth's
circumference. His value (based on the altitude of
the noontime sun as seen from Alexandria and
Syrene on the first day of summer) was
approximately 25,000 miles. The actual equatorial
circumference is 24,902 miles.
6. What is the diameter of
the earth?
The diameter of
the earth at the
equator is
7,926.41 miles
(12,756.32
kilometers).
7. SHAPE OF EARTH
Newton computed that the Earth's
shape should be an oblate
spheroid, a solid formed when an
ellipse is rotated about its axis
Expeditions to Peru in 1735 and to
Lapland in 1736 confirmed this
theory.
8. Rotation
The Earth spins on its axis from
West to East (counter-
clockwise). It takes the Earth 23
hours, 56 minutes, and 4.09
seconds to complete one full
turn. Day and night are
produced by the rotation of the
Earth. The speed of rotation at
any point upon the equator is at
the rate of approximately 1,038
miles per hour, decreasing to
zero
9. Revolution
While the Earth is spinning on its axis,
it is revolving around the Sun in a
counter-clockwise direction. It takes
the Earth one full year to complete one
full revolution around the Sun. This
path is known as the Earth's orbit. It is
very near a circle. The mean distance
of the Earth from the Sun is about 93
milling miles and the distance varies
by 3 million miles, forming a slightly
oval path.
10.
11. Effects of Earths Motion
Solstices
The solstices are days when the
Sun reaches its farthest
northern and southern
declinations. The winter solstice
occurs on December 21 or 22
and marks the beginning of
winter (this is the shortest day
of the year). The summer
solstice occurs on June 21 and
marks the beginning of summer
(this is the longest day of the
year).
12. Equinoxes
Equinoxes are days in which day and night are of
equal duration. The two yearly equinoxes occur
when the Sun crosses the celestial equator.
The vernal equinox occurs in late March (this is the
beginning of spring in the Northern Hemisphere
and the beginning of fall in the Southern
Hemisphere); the autumnal equinox occurs in late
September (this is the beginning of fall in the
Northern Hemisphere and the beginning of spring
in the Southern Hemisphere).
13. INTERNAL SRUCTURE OF EARTH
The Crust
Within the crust, intricate patterns are
created when rocks are redistributed
crust
anda deposited in layers through the
geologic processes of eruption and
intrusion of lava, erosion, and
consolidation of rock particles, and
solidification and recrystallization of
porous rock.
14. The Mantle
Our knowledge of the upper
mantle, including the tectonic
plates, is derived from analyses of
earthquake waves (see figure for
paths); heat flow, magnetic, and
gravity studies; and laboratory
experiments on rocks and
minerals. Between 100 and 200
kilometers below the Earth's
surface, the temperature of the
rock is near the melting point;
molten rock erupted by some
volcanoes originates in this region
of the mantle
15. The Core (Outer Core)
The outer core of the Earth is
a liquid layer about 2,266
kilometers thick composed of
iron and nickel which lies
above the Earth's solid inner
core and below its mantle. Its
outer boundary lies 2,890 km
(1,800 mi) beneath the Earth's
surface. The transition
between the inner core and
outer core is located
approximately 5,150 km
beneath the Earth's surface.
16. Inner core
The inner core of the Earth, its
innermost hottest part as
detected by seismological
studies, is a primarily solid ball
about 1,220 km (760 mi) in
radius,[1] or about 70% that of
the Moon. It is believed to
consist of an iron–nickel
alloy, and may have a
temperature similar to the Sun's
surface, approximately 5778 K
(5505 °C).[2]
17.
18. Earths Atmosphere
The atmosphere of Earth is a
layer of gases surrounding the
planet Earth that is retained by
Earth's gravity. The atmosphere
protects life on Earth by
absorbing ultraviolet solar
radiation, warming the surface
through heat retention
(greenhouse effect), and
reducing temperature extremes
between day and night (the
diurnal temperature variation).