3. • Mythologically speaking,
Gaia is a Greek word
that means “Earth” or
“land”.
• Earth is sometimes
referred to as the “blue
planet” or “blue marble”.
4. • The shape of Earth is
actually an oblate spheroid
and not a perfect sphere.
• The distance of Earth from
the sun, which is 149 600
000 km, is just the right
distance to support life.
5. The Day and Night Cycle
• The varying amounts of
sunlight received by Earth
during different times of the
year creates the seasons.
• Earth rotates in an unreal or
imaginary line that passes
through the North and South
Poles of the planet- this line
is called the axis of rotation.
6. What is the difference
between rotation and
revolution?
7. The Day and Night Cycle
• Rotation is the movement of the Earth on its
axis.
• Earth moves sideways at about 23.5 ̊angle or
tilt to the sun’s direction.
• Earth’s rotation period on its axis is 23 hours
and 56 minutes (approximately 24 hours).
9. The Day and Night Cycle
• Revolution is the circular movement of the Earth
around the sun.
• Earth completes one (1) revolution around the
sun in 365 ¼ days, which corresponds to the
length of one year on Earth.
• The pathway that Earth and other planets follow
as they revolve around the sun is known as
orbit.
10. The Day and Night Cycle
• The occurrence of day and night are the direct
consequences of the Earth’s spin on its axis.
• As Earth spins, the sun appears to “rise” and
“set”.
• The amount of the sunlight that reaches
different parts of Earth’s surface is influenced
by Earth’s tilted axis.
11. What causes the four seasons?
• The different seasons and
the amount of sunlight are
caused by the 23.5 ̊tilt of
Earth’s rotational axis
relative to the ecliptic
plane – the imaginary
surface formed by its
almost circular path as
Earth travels year-long
around the sun.
Summer
Winter Spring
Autumn
13. What causes the four seasons?
• Thus, at certain times of the year, one part of
the planet is more directly exposed to the rays
of the sun than the other parts.
• Temperate countries found between 23.5 ̊N
latitude and 66.5 ̊ N latitude, and between
23.5 ̊S latitude and 66.5 ̊S latitude experience
the four seasons (spring, summer, autumn, winter).
14. What causes the four seasons?
• The start of the season in both hemispheres is
distinguished by equinoxes and solstices.
• In an equinox, there is an equal length of day
and night in the northern and southern
hemisphere.
• At anytime during an equinox, one half is
lighted and the other half is dark.
15. What causes the four seasons?
• Earth is in a solstice if there is more light on half
of the hemisphere than on the other
hemisphere.
• The sun is directly overhead at noon at 23.5 ̊N-
this latitude is termed as the Tropic of Cancer.
16. What causes the four seasons?
• Tropic of Cancer
- the sun is directly overhead at noon at 23.5 ̊
- it is the most northerly circle of latitude on
Earth at which the sun may appear directly overhead
at its culmination
• The time of the year is called the summer solstice in
the northern hemisphere and winter solstice in the
southern hemisphere.
17. What causes the four seasons?
• Tropic of Capricorn
- the sun can be seen directly overhead by
noon at latitude approximately 23.5 ̊south of thr
terrestrial equator
18. What causes the four seasons?
• Tropic of Capricorn
- the time of the year is known as winter
solstice in the northern hemisphere and summer
solstice in the southern hemisphere
19. What causes the four seasons?
• Autumnal Equinox
- sunlight falls equally, and therefore, the day and
the night periods are of the same length throughout the
globe
- the season is the beginning of autumn in the
north hemisphere and spring in the southern
hemisphere
20. What causes the four seasons?
• Autumnal Equinox
- In temperate countries, some trees shed
their leaves during the autumn as a response to
the temperature being cooler
21. Climate and Seasons of the Philippines
Our country’s climate can be categorized into four general
types based on seasonal rainfall distribution.
TYPE I
-The dry season is from November to April,
and the wet season is observed the rest of the year.
22. Climate and Seasons of the Philippines
Our country’s climate can be categorized into four
general types based on seasonal rainfall distribution.
TYPE II
- The dry season has a very pronounced maximum
rain period that occurs in November and January in areas
near the eastern coast, namely, Catanduanes, Sorsogon,
the eastern part of Albay, the eastern and western part of
CamNorte and CamSur, the eastern parts of Quezon,
Samar, Leyte, and Mindanao (places are not covered from the
northeast winds and storms).
23. Climate and Seasons of the Philippines
Our country’s climate can be categorized into four general
types based on seasonal rainfall distribution.
TYPE III
- The relatively dry season from November to April
and the wet season during the rest of the year are not
very pronounced.
TYPE IV
- Rainfall is evenly distributed throughout the year.
24. The climatic condition of the Philippines is
characterized by two different features:
1. Difference in temperature is very small.
This means that any particular time of the
year, the temperature at sea level in the
southernmost island hardly differs from that in the
northernmost island.
25. The climatic condition of the Philippines is
characterized by two different features:
2. Differences in rainfall are large.
This is because mountain ranges that lie close
to the sea cause considerable distribution.
26. Because of these two features (temperature and
rainfall), the Philippines has three (3) seasons:
• Hot dry season or tag-init
- from March to May
• Rainy season or tag-ulan
- from June to November
• Cool dry season or taglamig
- from December to February
