Page 31 - Geography for Secondary Schools Student’s Book Form One

Geography for Secondary Schools
Student’s Book Form One
(v) Tides

Ocean tide is the rising and falling of water level in oceans as shown in Figure 3.4. This
is caused by gravitational attraction exerted largely by the moon and partly by the Sun
upon the rotating earth. The main reason why the gravitational attraction of the moon
is greater compared to that of the Sun is that the moon is closer to the Earth compared
to the long distance from the Sun. When the Earth, moon, and the sun are in a straight
2. FOR ONLINE READING ONLY
line, ocean water level rises and when the earth, moon, and the sun are not in a straight
line, the ocean water level falls. Tides are experienced at different times of the day and
at night and in different places on the earth’s surface, because the earth is rotating.

Figure 3.3 (b): World map showing deflection of ocean currents

High tide

Tidal range Low tide

Sea Land

Figure 3.4: Low and high tide levels of the ocean water

Exercise 3.3 Revolution of the Earth

1. Explain the factors that affect the Activity 3.4
deflection of winds and ocean currents.

What is the importance of knowledge (a) Search for videos, simulation, or
animations from reliable online
of deflection of winds and ocean sources on how the Earth revolves
currents in your daily life? around the Sun and how the Moon
revolves around the Earth;
3. Do tides happen in lakes and rivers, (b) Observe what happens during
or just in the ocean? Why? the movements, and record your
4. What is the importance of the low and observation; and
high tides to your life? (c) Draw an illustration of what you
have observed.

25

18/10/2024 18:32:33
GEOGRAPHY (F1) TO PRESS.indd 25
GEOGRAPHY (F1) TO PRESS.indd 25 18/10/2024 18:32:33