Our Changing Earth

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 Ref: http://static1.mbtfiles.co.uk

1. The lithosphere is broken into a number of plates. These plates move around
very slowly – just a few millimeters each year because of the movement of the
molten magma inside the earth which moves in a circular manner. What are
these broken plates known as?
a. Tectonic plates/Lithospheric plates
b. Farallon plate /Lithosph
c. Scotia plate
d. Oceanic plates

2. The movements on earth are divided on the basis of the forces which cause
them. What are the forces which act on of the surface of earth called?
a. Endogenic forces
b. Exogenic forces
c. Rotation
d. Gravitational force

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3. Earthquakes cannot be predicted but the impact can certainly be (3 Marks)
minimised if we are prepared before-hand. We should spread awareness
about the safety measures to be used during this natural disaster. During
an earthquake we should keep away from which all places?

4. Complete the table: (4 Marks)

a. Angel falls
b. Niagra
ictroia
d. Jog

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5.
The forces which act in the interior of the earth are known as (1
Mark) Endogenic forces. The Endogenic forces have two types: Sudden forces
and Diastrophic forces. Sudden forces include earthquakes, volcanoes,
landslides which causes mass destruction on the surface of earth. Likewise
give an example of diastrophic forces. a. Lava eruption
b. Glacier
c. Building mountain
d. Soil erosion

6. The movement of Lithospheric plates causes changes on the surface (1

Mark) of the earth. The earth movements are
divided on the basis of the forces which cause
them. What are the forces which act in the
interior of the earth are called?

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7. The movement of Lithospheric plates causes them to vibrate. These (3 Marks)
vibrations can travel all round the earth and are known as earthquakes.
Where does this vibration initiate? Where does the greatest damage
happen? Explain.

8. Observe the figure and complete it:

NAILED IT!

9. Magma is hot fluid or semi-fluid material below or within the (1 Mark)

earth's crust from which lava and other igneous rock is formed on cooling. In
what motion does the molten magma move inside the earth?

10. Earthquakes cannot be predicted, the impact can certainly be (1

Mark) minimised if we are prepared before-handed. Some common
earthquake prediction methods include studying animal behavior; fish in the
ponds get agitated, snakes come to the surface. What is the machine, through
which the earthquake is measured know as?

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11. We cannot stop earthquake, but we can reduce its impact by being (3 Marks)
prepared for it. Imagine if a quake suddenly shook in the middle of the
school day, where would you go for safety?

Ref: https://www.portlandoregon.gov

EXOGENIC FORCES-RIVERS AND SEA WAVES

River Carving Valley Wave cutting back cliffs

12. Weathering is the breaking up of the rocks on the earth’s surface. Erosion is the
wearing away of the landscape by different agents like water, wind and ice.
Which activity in a river erodes the landscape?
a. Growth of weeds
b. Boating
c. Swimming of humans
d. Running water

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 Humans change the environment to make their lives safer and more
comfortable. Which environment is this modification of natural environment by
humans to meet their ever -growing needs for food, money

a. The Human Environment

b. The Forest Environment
c. The Natural Environment
d. The Animal Environment

14. Identify the features marked A, B and C (3 Marks)

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 Multiple Choice Questions (1 Mark Each)

15. Canada has the longest coastline at 243,792 km or 151,485 miles. In our
country, Gujarat has the longest coastline of all the states. What is a steep
rocky coast rising almost vertically above the sea water is called? a. Rock coast
b. Coast mountains
c. Sea cliff
d. Rock cliff

16. At times the rivers overflows its banks. This leads to the flooding (1
Mark) of the neighboring areas. As it floods it deposits sediments and layers
of fine soil along its banks. What type of floodplain is formed?

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17. As a river floods it deposits sediments and layers of fine soil along (1 Mark)
its banks, which leads to formation of flat fertile floodplain. At the
sides of such floodplains, there are raised banks, what are they called?

18. What is formed as the river enters the plain and it twists and turns (3 Marks)
forming large bends?

19. If meander loop cuts off from the river and forms a cut-off lake, (1 Mark)
what is it called?

20. As the river approaches the sea, the speed of the flowing water (1 Mark)
decreases and the river begins to break up into number of
streams. What is collection of such streams called?

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21. Label the diagram and explain how the feature is formed. (3 Marks)

22. Observe the diagram carefully and Identify water fall, meanders, (4 Marks)
oxbow lakes and delta. Explain how meanders, oxbow lakes and
delta are formed at different stages.

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 EXOGENIC FORCES– ICE AND WIND

Wind blowing topsoil

Glacier moving rocks

23. Glaciers are “rivers” of ice. Siachen Glacier is the second longest glacier outside
of the polar regions and largest in the Himalayas-Karakoram region. Glaciers
erode the landscape by bulldozing soil and stones, with this activity what do
they expose?
a. Solid rocks
b. Molten lava
c. Water animals
d. Non-corrosive metals

24. Glaciers carve out deep hollows and as the ice melts they get filled up with wa-
ter in mountains, and forms what?
a. Oceans
b. Delta
c. Lakes
d. Stacks

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25. Match The following: (3 Marks)

Column A Column B
1. Glacier a. Sea shore
2. Beach b. River of ice
3. Meanders c. Rivers
4. Sand dunes d. Vibrations of the earth
5. Water fall e. Hard bedrock
6. Earthquake f. Deserts
Answers

1 2 3 4 5 6

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 Multiple Choice Questions (1 Mark)
26. When the wind blows, it lifts and transports sand from one place to another.
When it stops blowing the sand falls and gets deposited in low hill – like
structures. What are these sand like structures known as? a) Desert mounds
b) Sand dunes
c) Sand waves
d) Mushroom rocks

27. As the ice from the glaciers melt they get filled up with water and (1
Mark) forms the beautiful lakes in mountains. The material carried by the
glacier such as rocks, sand, silt, etc. get deposited. What are these deposits
called?

28. An active agent of erosion and deposition in the deserts is wind. It (1

Mark) can sometimes blow sand to form towering dunes. What is the shape of
rocks in the deserts?

29. When the grains of sand are very fine and light, the wind can carry (3 Marks) it over
very long distances. When such sand is deposited in large areas, What is it called? Where
are such large deposits found?

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30. Winds erode the lower section of the mushroom rocks more than (1 Mark)
the upper part. Therefore, such rocks have what kind of base?

31. When the grains of sand are very fine and light, the wind can carry it (1 Mark)
over very long distances. When such sand is deposited in large areas,
what is it called?

32. Give reasons – “Some rocks have a shape of a mushroom” (3 Marks)

33. Why is action of wind more prominent in arid and semi-arid regions? (4 Marks)

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34. Why do human beings throw waste such as wrappers, plastic bottles, polythene
bags on roads and in water bodies? How does it affect our environment?

35. Glaciers carve out deep hollows. Give reason.

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