motions of aerth

1. EIGHT MOTIONS OF EARTH
MEMB ER S:
MARY JOY BERNABE
NELMARIE RIVERA
NICOLE ANDRIEL PRAGOSO
NOVA UGBINADA
PAMELA RICO
RHODARINE BANTAD
ROSALIEALITAO

2. OBJECTIVE:
• Differentiating the types of
varations and emotions of the
effects.
• Explaining different land forms area
of the Earth

3. 1. The Earth Rotates About Its Axis
 Earth moves through space in several important ways. One type of
motion is called rotation. A rotation is a spin around a center.
 Earth also spins around a central line called an axis. Earth’s axis is an
imaginary vertical line that runs through the planet from the North Pole
to the South Pole.
• The Earth has a circumference (measured around at the Equator) of
approximately 40,075 km (24,901 mi). And 40,007.863 km
(24,859.734 mi) when measured around the poles.
• The Earth rotates on its axis relative to the Sun in one “Mean Solar Day"
• It rotates exactly 360° in one "Mean Sidereal Day" which is 86,164.0909
seconds, or 23 hrs 56 min 4.0909 seconds.

4. Solar day (24 hours)
The Earth makes one rotation compared with the Sun.
3 minutes 56 seconds longer than a sidereal day.
Sidereal day (23 hours 56 minutes 4.0909 seconds)
The Earth makes one rotation compared with the distant
stars.
3 minutes 56 seconds shorter than a solar day

5. 2. Earth-Moon System Orbits a "Gravitational Centre"
● Both the Moon and the Earth orbit
a common centre of gravity
● The mass of the Earth (ME) is
5.9742 * 1024 kg, and the mass of
the Moon is 7.349 * 1022 kg - the
Ratio of the masses is 81.3
● So the centre of gravity is
therefore located 1 unit from the
Earth's centre and 81.3 units from
the Moon's centre
● Earth pivots around this point
once every Lunar Month

6. ● The Earth's orbit around the Sun is an
ellipse and travels at different speeds
during the year - slowest at Aphelion
(furthest point from the Sun) and fastest
at Perihelion (closest point to the Sun)
● Earth's orbit (the path) is approximately
940,000,000 km (580,000,000 mi) in
365.2421896698 days
● So the "year" is not exactly 365¼ days
(sometimes called the Julian Year).
● Earth's speed around the sun Speed =
distance/time = circumference/time =
939,951,145 km / (365.2421896698 days
* 24 hr/day) = 107,229 km/hr (66,629
mi/hr)
3. The Earth Revolves Around the Sun Once a Year

7. ● The Sun's mass is 1.9891 * 1030 kg it is 332,950 times
heavier than the Earth. The Earth does cause the Sun to
wobble but it is a very tiny motion.
● On the other hand, Jupiter (the heaviest planet in the
solar system) causes a much more appreciable wobble in
the Sun.
● Sun wobbles around a point just outside its surface every
11.859 years (the length of Jupiter's orbit).
● Although slow, this wobble is detectable - and it also
means the Earth is orbiting a slowly wobbling Sun
4. The Sun and Earth Revolve Around the Solar
System "Gravitational Centre"

8. ● The Earth's North-South rotation
axis "wobbles" like the slow
rotational tilting of a spinning top
over a period of 25,770 years. This
is known as Precession and affects
the direction in the sky to which
the North Pole points and, in fact,
the orientation of the entire orbital
path of the Earth.
5. The Earth's Orbit Precesses every 25,770 years

9. ● Precession is caused by
the gravitational
attraction of the Sun
(and the Moon) tugging
on the Earth's equatorial
bulge.

10. ● The Sun is located near the Orion
arm, between two major arms
(Perseus and Sagittarius). The
diameter of the Milky Way is about
100,000 light-years and the Sun
is located about 28,000 light-
years from the Galactic Center.
● It takes the sun approximately
255-250 years to complete one
journey.
6. The Sun Revolves Around the Galaxy Once Every
250 Million Years

11. ● The Milky Way Galaxy and the Andromeda
Galaxy are approaching each other at
about 400 km/s
7. The Galaxy is moving through the Universe

12. ● The Earth wobbles causing the location of the
North and South Poles to vary by 3 to 15 m.
● This Chandler Wobble causes the latitude of any
position on the Earth to move a few metres in this
14 month cycle and affects GPS readings
8.Polar Variation - small but needs to be mentioned

13. DIFFERENT FORMS LAND AREA OF
THE EATH

14. ● Mountains are landforms
higher than the surrounding
areas. They are formed due
to the tectonic movements,
earthquakes, volcanic
eruptions and erosion of the
surrounding areas caused
due to wind, water and ice.
Mountains are found in the
oceans and on land.
Mountains

15. ● Plateaus are flat highlands
that are separated from the
surroundings due to steep
slopes. They are formed by
collisions of tectonic
plates, magma action that
causes the elevation in
earth’s crust.
Plateaus

16. ● Valleys are low-lying areas of land
between hills and mountains that
are formed due to the actions of
glaciers and rivers over millions of
years. Depending on the shape
they are classified as V shaped
valleys and U shaped valleys. V-
shaped valleys are formed by the
flowing rivers and U-shaped valleys
are formed due to glaciers.
Valleys

17. ● Due to lack of adequate rainfall,
desert is a dry piece of land with
little or no vegetation. They are
mostly found mainly in rain
shadow areas which are leeward of
a mountain range with respect to
the wind direction. In deserts, the
atmospheric air is very dry, and
daytime temperature is high.
Deserts

18. ● Dunes are mounds or small hills
made up of sand that are created
due to the action of and water flow
(under water dunes). It may be
dome-shaped, crescent-shaped,
star-shaped, linear-shaped, and
many more. The height of a dune
hill can be as low as 1 meter, or as
high as 10 meter and more.
Dunes

19. ● An island is a piece of
land which is
surrounded by water
from all sides and
formed either due to
volcanic eruptions or
due to hot spots in the
lithosphere.
Islands

20. ● Plains are flat or the low relief
areas on the surface of the
earth. It might be formed as a
result of the sedimentation of
eroded soil from the top of the
hills and mountains or might be
due to flowing lava deposited by
the agents of wind, water, and
ice.
Plains

21. ● Rivers are natural
flowing streams of fresh
water descending from
mountains. They
mostly flow toward a
lake, sea, ocean or
another river.
Rivers

22. ● Oceans are the biggest water
bodies found on earth and are
saline in nature. Oceans cover
over 71% of the earth’s surface
and are responsible in
controlling the weather and
climate of the earth. Oceans
originated due to continental
drifts i.e. the movement of the
earth’s tectonic plates.
Oceans

23. ● Loess are deposition of
silt, with a little amount
of sand and clay. They
appear yellowish or
brownish in color. Wind
action or glacial
activities are responsible
for formation of loess.
Loess

24. ● Glaciers are slow moving huge
bodies of ice formed due to
the compression of the snow
layers. They move depending
on the pressure and gravity.
There are two types of
glaciers, the alpine glaciers
which can be located in high
mountains and the
continental glaciers which can
be located in cold Polar
regions.
Glaciers

25. ● Peninsulas are large land
areas that extend into
water bodies. They remain
surrounded by water on
three sides. Peninsulas are
formed by lithospheric
movements and action of
water currents.
Peninsulas

26. ● Deltas are low-lying,
triangle-shaped areas,
located at the mouth of
rivers. In the course of
creating a delta, the sand,
silt, and rock particles are
accumulated in a nearly
triangular shape.
Deltas
‘Mississippi river delta’

27. THE MODERN ATOMIC THEORY
R EF ER ENC Es:
 http: / / earthsci.org/ space/ space/ earth8/ earth8
.html
 https: / / schooltutoring.com/ help/ earth
sciences types of landforms/
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