Page 35 - Geography for Secondary Schools Student’s Book Form One

Geography for Secondary Schools
Student’s Book Form One

Exercise 3.4

1. Discuss the effects of the earth’s revolution in your area.
2. Explain the common economic activities carried out in your area in different
seasons of the year.

FOR ONLINE READING ONLY
Activity 3.6
1. Think of your community at home town or village, and relate the seasons of the
year with their daily activities. Use the following questions for guidance:
(a) What activities do they conduct in each season?
(b) Why do you think they do such activities in that particular season?

2. Write short essay on the activities done in relation to the seasons of the year.

(iv) Aphelion and Perihelion
The Earth revolves around the sun in an elliptical orbit. Due to the elliptical shape of
the earth’s orbit, the Sun is closer to the Earth at one point of the year than at the other
(Figure 3.7). The furthest position from the sun in the orbit of the earth is called aphelion.
Normally, the Earth is at aphelion each year on 4 July when it is 152 million kilometres
th
away from the Sun. Perihelion occurs when the Earth is nearest to the Sun about 147
million kilometres away from the Sun. The Earth is at perihelion each year on the 3
rd
of January. Aphelion and perihelion affect the amount of solar radiation received by
the Earth, though their influence on the seasons is much smaller than the axial tilt. The
slight variation in solar radiation due to Earth’s changing distance from the Sun during
its orbit is not sufficient to cause significant climate change or shifts in seasons.

Figure 3.7: Perihelion and aphelion

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