Natural Disasters
Theme 5 : The Environment - Major Concerns (My Watch Tower Social Studies)
Time to Camp - Exercises
A. Choose the correct answers and fill the OMR box.
1. The point where the moving plates collide with each other is called the _________ .
a. metrocentre. [ ]
b. hypocentre. [✓]
c. epicentre. [ ]
d. magma. [ ]
2. An opening through which lava comes out is called ________ .
a. vent. [✓]
b. focus. [ ]
c. magma. [ ]
d. flood. [ ]
3. _________ falls within India's drought-prone zone.
a. West Bengal. [ ]
b. Assam. [ ]
c. Rajasthan. [✓]
d. flood. [ ]
4. A/An _________ may form when there is how pressure over a warm sea.
a. tsunami. [ ]
b. landslide. [ ]
c. earthquake. [ ]
d. cyclone. [✓]
5. Cyclone break over _________ .
a. sea. [ ]
b. land. [✓]
c. water. [ ]
d. mantle. [ ]
B. Fill in the blanks.
1. Landslides are caused by heavy rains.
2. Planting more trees could prevent drought.
3. The magma which spills onto the Earth's surface is called lava.
4. Scarcity of drinking water and food are very common during floods.
C. State whether true or false.
1. Floods do not lead to a shortage of drinking water. [F]
2. Landslide can be caused by volcanoes. [T]
3. Cyclones usually occur in the coastal regions. [T]
4. Magma that spreads over the Earth's surface is called lava. [T]
D. Answer these questions.
1. What causes earthquakes? What precautions should we take during earthquakes?
= The Earth's crust, comprising rocks and soil, is the outermost solid shell of our planet. It is also the thinnest layer and is broken into many pieces called plates. These plates float on the semi-liquid layer of the Earth called mantle, located just beneath the crust. These plates are constantly moving and when they collide with each other, it cause vibrations or tremors. These tremors shake the Earth's crust causing earthquakes.
During an earthquakes, these measures should be followed.
❐ Run into an open area away from buildings and tall trees as they can fall and hurt you.
❐ Use the staircase instead of lifts.
❐ In case you are indoors and cannot go out, then go under a strong table or bed.
2. Write a short not on causes and effects of droughts.
= Causes of droughts :- During the dry season, many lakes and ponds dry up leading to water scarcity in some areas. People eagerly look forward to the rains but sometimes even the monsoons fail. This leads to drought conditions.
Effects of droughts :- Crops production is immensely affected during droughts and causes loss of human and animal life.
3. Why do volcanic eruptions occur?
= The centre of the Earth, very much like a pressure cooker, also has tremendous heat and pressure. Sometimes, the heat builds up to a great intensity and molten material inside the Earth rushes out through cracks or openings on the Earth's surface. This is called volcanic eruptions.
4. What causes floods and what precautions should be taken during this disaster?
= Causes of flood :- Floods occur when an area receives very heavy rainfall and nearby water bodies fill up and overflow into the surrounding lands.
Precautions :-
❐ Move to a higher ground to prevent yourself form flood waters.
❐ Keep clean drinking water, food and necessary medicines with you.
❐ Turn off electrical and gas supplies.
5. Why do you think it is difficult to predict the occurrence of natural disasters?
= Human activities disturb the natural environment of Earth. Humans, however, are also subject to nature's fury. Then natural forces act to create devastating events such as floods, and property. A natural disaster may cause little or tremendous damage depending on the intensity of the disaster. People take a long time to resume their normal lives after the occurrence of a natural disaster.
Picture Study
Look at the picture and answer the questions.
1. What type of natural disaster is being shown here?
= Volcanic eruption is being shown here.
2. State the effects of such a disaster.
= Volcanic lava along with ash covers long distances and covers everything in its path. Whole cities and towns that fall in the path of lava can be obliterated. Explosive volcanic eruptions may also lead to submergence of whole islands or rise of new islands. The lava, when it cools down, forms volcanic rocks and soil.
3. List some precautionary measures.
= If we live in a region near an active volcano, we should remember the following safety rules:-
❐ Move to a safe place when there is a volcanic eruption.
❐ Keep food, medicines and water with you.
❐ Keep yourself updated with government announcements.