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Class 9 SST Chapter 2 Shaping of the Earth’s Surface Question Answer
Class 9 Shaping of the Earth’s Surface Question Answer
The Big Questions (Page No. 13)
Question 1.
What shapes the Earth’s surface?
Answer:
The Earth’s surface is shaped by a combination of internal and external forces that continuously change the landscape. Internal forces originate within the Earth and include tectonic movements, volcanic eruptions, and earthquakes. These forces create major landforms such as mountains, plateaus, and valleys.
External forces work on the Earth’s surface and include weathering, erosion, transportation, and deposition caused by rivers, glaciers, wind, waves, and underground water. These processes wear down high areas and deposit materials in low-lying regions, creating features such as deltas, beaches, caves, and plains.
Thus, the Earth’s surface is constantly being reshaped by the interaction of both internal and external forces, making it dynamic rather than static.
Question 2.
What is plate tectonics? What are the effects of plate movement?
Answer:
Plate tectonics is a scientific theory that explains how the Earth’s outer layer, called the lithosphere, is divided into several large and small tectonic plates. These plates float and move slowly over the semi-molten asthenosphere beneath them due to convection currents in the mantle.
The movement of tectonic plates has several important effects:
- Formation of fold mountains such as the Himalayas.
- Occurrence of earthquakes along plate boundaries.
- Formation of volcanoes when magma rises to the surface.
- Creation of ocean basins and mid-ocean ridges.
- Changes in the position of continents and oceans over time.
Although plate movements are very slow, they have shaped the Earth over millions of years and continue to influence natural events today. Understanding plate tectonics helps us identify earthquake-prone and volcanic regions and improve disaster preparedness.
Question 3.
How are landforms formed and how are they classified?
Answer:
Landforms are natural features found on the Earth’s surface. They are formed through various geological processes such as tectonic activity, weathering, erosion, transportation, and deposition.
Some landforms are created by internal forces. For example:
- Mountains are formed by plate collisions.
- Volcanoes are formed when magma reaches the Earth’s surface.
Other landforms are formed by external forces:
- Rivers create waterfalls, meanders, and deltas.
- Waves create beaches, sea cliffs, and sea arches.
- Glaciers form U-shaped valleys and moraines.
- Wind forms dunes and yardangs.
- Underground water creates caves and sinkholes.
Landforms are formed by internal forces such as plate tectonics and by external processes such as weathering, erosion, transportation, and deposition carried by rivers, glaciers, wind, waves and underground water. This classification helps geographers understand the processes responsible for shaping the Earth’s surface.
Question 4.
How are humans and other living beings connected to these landforms?
Answer:
Humans and other living beings are closely connected to landforms because landforms influence where people live, what they grow, how they travel, and how they earn their livelihoods.
Fertile river valleys and deltas support agriculture and dense settlements. Mountains provide fresh water, forests, and tourism opportunities. Coastal regions support fishing, trade, and transportation. Glaciers act as important sources of freshwater for millions of people.
Different landforms provide suitable habitats for plants and animals. Forests grow on mountain slopes, wetlands develop in river deltas, and many species thrive in coastal and desert environments.
Throughout history, landforms have influenced the rise of civilizations, trade routes, cultural exchanges, and economic activities. Therefore, human life and natural ecosystems are deeply connected with the Earth’s landforms.
Question 5.
How do disasters associated with different landforms impact human lives?
Answer:
Different landforms are associated with specific natural disasters that can significantly affect human life and property.
Mountain regions may experience landslides, avalanches, and Glacial Lake Outburst Floods. (GLOFs). These disasters can destroy roads, bridges, houses, and agricultural land, causing loss of life and disrupting communication.
Earthquake-prone regions may suffer severe damage to buildings and infrastructure due to tectonic activity. Coastal regions can face erosion and flooding, while arid regions may experience dust storms that affect agriculture and health.
These disasters not only cause immediate destruction but also affect livelihoods, education, transportation, and economic development. However, understanding landforms and the processes that shape them helps governments and communities plan better, reduce risks, and protect lives through disaster management and sustainable development practices.
Shaping of the Earth’s Surface Question Answer Class 9
InText Questions
Let’s Map
Question 1.
Pick any two plates from the map below and complete the table given below. (Page 17)
Answer:
| Name of the Plate | Continents | Ocean |
| Indo-Australian Plate | Australia and parts of Asia (including India) | Indian Ocean |
| South American Plate | South America | Atlantic Ocean |
Let’s Explore
Question 1.
Examine the plate map given above with the earthquake and volcano map given below. What correlation do you observe? (Page 17)
Answer:
After comparing the two maps, we observe that most earthquakes and volcanoes are concentrated along tectonic plate boundaries. Areas where plates meet are highly active because the movement of plates causes stress, friction, and the release of energy.
For example:
(i) The Pacific Ring of Fire has a large number of volcanoes and earthquakes.
(if) Regions near convergent and transform plate boundaries experience frequent seismic activity.
(iii) Very few earthquakes and volcanoes occur in the stable interior regions of plates.
This correlation shows that tectonic plate movement is the main cause of earthquakes and volcanic eruptions. The maps clearly demonstrate that plate boundaries are the most active geological zones on Earth.
Question 2.
Observe the map showing the distribution of earthquakes and volcanoes (Figure). Can you identify which continents and countries are located around the Ring of Fire with the help of an atlas or a globe? (Page 17)
Answer:
The Ring of Fire is a vast zone surrounding the Pacific Ocean where a large number of earthquakes and volcanoes occur. It lies along active tectonic plate boundaries and is considered the most geologically active region in the world.
The continents located around the Ring of Fire are Asia, North America, South America, and Australia (Oceania). Some important countries situated in this region include Japan, Indonesia, the Philippines, New Zealand, the United States, Canada, Mexico, Peru, Chile, and Ecuador.
These countries frequently experience earthquakes and volcanic eruptions because they are located near convergent and transform plate boundaries where tectonic plates collide, separate, or slide past one another. The Ring of Fire demonstrates the close relationship between plate tectonics and natural phenomena such as earthquakes and volcanoes.
Question 3.
Does India have a risk of earthquakes?
India has experienced some major earthquakes in ,the past, resulting in thousands of deaths. A large earthquake in a densely populated country like India can cause severe damage to life and environment. (Page 17)
Figure: The extensive damage caused by the major earthquake in Gujarat in 2001
Can you find out which region is more vulnerable to earthquakes? Why do you think human lives are at risk?
Answer:
Yes, India is highly vulnerable to earthquakes because it is located near active tectonic plate boundaries. The Indian Plate is continuously moving northward and colliding with the Eurasian Plate, which has led to the formation of the Himalayas and continues to generate seismic activity.
The regions that are most vulnerable to earthquakes include the Himalayan region (Jammu and Kashmir, Himachal Pradesh, Uttarakhand), the North-Eastern states, parts of Bihar, the Kutch region of Gujarat, and the Andaman and Nicobar Islands. These regions are more vulnerable because of the movement and collision of the Indian plate with Eurasian plate.
Human lives are at risk because strong earthquakes can cause the collapse of buildings, bridges, roads, schools, and hospitals. In densely populated areas, a large number of people may be injured or killed. Earthquakes can also trigger landslides, fires, and damage to communication and transport networks, disrupting normal life and causing significant economic and environmental losses. Therefore, understanding earthquake-prone regions and adopting proper disaster preparedness measures are essential for reducing risks and protecting lives.
Question 4.
Look carefully at this photograph and answer the following questions:”
(i) What do you think caused this situation?
(ii) What could that grey powder be?
(iii) What does it tell us about the Earth’s internal forces? (Page 18)
Answer:
(i) This situation was most likely caused by a volcanic eruption. During an eruption, molten rock (magma), gases, ash, and other materials are released from inside the Earth onto its surface. The eruption spreads volcanic materials over a large area, changing the landscape and affecting living organisms and human activities.
(ii) The grey powder visible in the photograph is volcanic ash. It consists of tiny particles of rock, minerals, and volcanic glass that are thrown into the atmosphere during a volcanic eruption. These particles eventually settle on the ground, covering vegetation, buildings, roads, and agricultural fields.
(iii) The photograph shows that powerful internal forces are continuously active within the Earth. Heat and pressure inside the Earth can force magma to rise to the surface through cracks or vents, resulting in volcanic eruptions. These internal forces play an important role in shaping the Earth’s surface by creating new landforms and bringing about significant changes in the natural environment. The photograph highlights that the Earth is dynamic and constantly changing due to processes occurring deep within it.
Question 5.
Observe the photographs given below and also note the types of erosion. How are farmers affected by erosion due to water and wind? (Page 21)
Figure. Erosion caused by (a) water and (b) wind
Answer:
Types of erosion shown in the photographs:
- Water erosion – Flowing water wears away and carries fertile topsoil, forming gullies and channels.
- Wind erosion – Strong winds remove loose and dry topsoil, especially in arid and semi-arid regions.
Water and wind erosion remove the fertile topsoil needed for crop growth, reducing soil fertility and lowering agricultural yields. Water erosion can wash away soil and crops, while wind erosion blows away fine soil particles from fields. As a result, farming becomes less productive and farmers face difficulties in growing healthy crops.
Question 6.
Have you heard about the Sundarbans delta? Try and explore its uniqueness and find out why it is popular with tourists. (Page 25)
Answer:
The Sundarbans Delta is the world’s Ingest delta, formed by the rivers Ganga, Brahmaputra, and Meghna before they flow into the Bay of Bengal. It is spread across parts of India and Bangladesh and is famous for its vast network of rivers, distributaries, tidal creeks, mudflats,, and islands.
The most unique feature of the Sundarbans is its extensive mangrove forests. It is one of the largest mangrove forests in the world. These forests are specially adapted to survive in salty and waterlogged conditions. The region is also a UNESCO World Heritage Site and is known for its rich biodiversity. It provides habitat to many species of animals, including the famous Royal Bengal Tiger, estuarine crocodiles, spotted deer, fishing cats, and numerous species of birds and aquatic life.
The Sundarbans is popular with tourists because of its unique natural beauty, dense mangrove forests, winding waterways, and diverse wildlife. Visitors are attracted by boat safaris, birdwatching, wildlife photography, and the opportunity to observe the Royal Bengal Tiger in its natural habitat. The delta also plays an important role in protecting coastal areas from cyclones and tidal waves, making it an ecologically significant region.
Thus, the Sundarbans Delta is unique not only because it is the largest delta in the world but also because of its rich biodiversity, mangrove ecosystem, and importance for both nature conservation and tourism.
Question 7.
Observe the landforms around your school or residence and try to identify which agent may have created them. (Page 32)
Answer:
Do it yourself.
Question 8.
Complete the exercises given below of each type of disaster with the help of newspapers, atlases, and books. Make a list of disaster-prone areas from India and the world and enlist mitigation measures quoting recent examples. (Page 32-36)
1. Landslides: prone areas, mitigation measures and recent examples
2. Avalanches: prone areas, mitigation measures and recent examples
3. GLOFs: prone areas, mitigation measures and recent examples
4. Dust Storms: prone areas, mitigation measures and recent examples
Answer:
| Disaster | Prone Areas | Mitigation Measures | Recent Examples |
| Landslides | Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh, Kerala (Western Ghats) | Afforestation; avoid construction on unstable slopes; construct retaining walls and proper drainage systems; follow landslide early warning systems; regulate quarrying and deforestation. | Wayanad Landslides, Kerala (2024); Himachal Pradesh landslides during the monsoon (2025). |
| Avalanches | Ladakh, Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Sikkim | Avalanche forecasting and early warning systems; avoid travel during heavy snowfall; construct avalanche barriers; monitor weather conditions; create public awareness. | Mana Avalanche, Uttarakhand (2025); Avalanches in Ladakh during winter (2025). |
| GLOFs (Glacial Lake Outburst Floods) | Sikkim, Uttarakhand, Himachal Pradesh, Arunachal Pradesh, Ladakh | Monitor glacial lakes; install early warning systems; strengthen embankments; prepare evacuation plans; promote climate-resilient development. | South Lhonak Lake GLOF, Sikkim (2023); Floods caused by glacial lake breaches in the Himalayan region (recent years). |
| Dust
Storms |
Rajasthan (Thar Desert), Gujarat, Haryana, Punjab, Western Uttar Pradesh | Plant shelter belts; prevent overgrazing; practise soil conservation; promote sustainable farming; follow weather advisories and early warning systems. | Dust storms in Rajasthan and north-western India (2025); Dust storms affecting Delhi-NCR during summer (2025). |
Think about it
Question 1.
A devastating flood struck the Chamoli, district in Uttarakhand in February 2021 in which many people and livestock lost their lives? Therb was severe damage to buildings, roads, bridges,, and hydel projects, and connectivity to villages was adversely affected. Can you find out the reasons that led to the sudden and unexpected flood? (Page 29)
Answer:
The sudden and unexpected flood was caused by:
- The collapse of a large mass of rock and ice from a Himalayan mountain slope.
- A sudden surge of water and debris into the Rishiganga and Dhauliganga rivers.
- The steep mountainous terrain, which increased the speed and force of the flood.
Shaping of the Earth’s Surface Class 9 Questions and Answers
Questions and Activities (Page No. 37-38)
Question 1.
What are the sources of energy that are required to cause movements associated with the internal forces of the Earth?
Answer:
The movements associated with the internal forces of the Earth are mainly caused by the heat energy present inside the Earth. This heat comes from the Earth’s core and generates convection currents in the mantle, which move the tectonic plates. Radioactive decay of minerals inside the Earth also produces heat energy. These forces lead to earthquakes, volcanic eruptions, folding, and faulting.
Question 2.
Relate various physiographic divisions you have studied in the earlier grades with various endogenic forces responsible for their origin.
Answer:
| Physiographic Division | Endogenic Force Responsible |
| Himalayas | Folding due to collision of tectonic plates |
| Block Mountains and Rift Valleys | Faulting |
| Deccan Plateau | Volcanic activity |
| Volcanoes and Volcanic Islands | Volcanic eruptions |
| Mountain Ranges | Plate movements and folding |
| Earthquake-prone regions | Tectonic plate movements |
These landforms were formed due to internal forces such as folding, faulting, volcanic activity, and plate tectonics.
Question 3.
Why and where do earthquakes occur frequently? Is it possible to predict earthquakes?
Answer:
Earthquakes occur frequently because of the sudden release of energy when tectonic plates move, collide, separate, or slide past one another. They mainly occur along plate boundaries, especially around the Pacific Ring of Fire, the Himalayan region, and other tectonically active zones. At present, earthquakes cannot be predicted accurately in terms of exact time and location, although scientists can identify earthquake-prone regions and monitor seismic activity.
Question 4.
“Plate movements are responsible for the distribution of earthquakes and volcanoes.” Explain.
Answer:
Most earthquakes and volcanoes occur along tectonic plate boundaries. When plates collide, diverge, or slide past each other, stress builds up and is released in the form of earthquakes. At convergent and divergent boundaries, magma may rise to the surface, causing volcanic eruptions. Therefore, the distribution of earthquakes and volcanoes closely follows the pattern of tectonic plate boundaries, especially around the Pacific Ring of Fire.
Question 5.
Draw and label a diagram of a meander and a delta.
Answer:
Do it yourself.
Question 6.
How are deforestation and erosion associated with each other? Explain.
Answer:
Deforestation removes trees and vegetation that bind the soil with their roots. Without plant cover, the soil becomes loose and exposed to wind and water. As a result, erosion increases and the fertile topsoil is washed or blown away. Therefore, deforestation directly contributes to soil erosion and land degradation.
Question 7.
Develop a plan to protect the land in your local area from erosion.
Answer:
A plan to protect land from erosion may include:
- Plant more trees and grasses to bind the soil.
- Prevent deforestation and overgrazing.
- Construct contour trenches and bunds on slopes.
- Promote terracing in hilly areas.
- Build check dams to reduce the speed of flowing water.
- Encourage sustainable farming practices.
- Create awareness among local people about soil conservation.
- Maintain proper drainage systems to prevent waterlogging and runoff.
These measures help conserve soil and reduce erosion effectively.
Question 8.
Which disasters do you think you might experience in your region? Discuss a mitigation plan in your classroom.
Answer:
Do it yourself.
Question 9.
Prepare a model of landforms created by underground water.
Answer:
Do it yourself.
Question 10.
What precautionary measures will you take if you are staying in an earthquake-prone region?
Answer:
- Construct earthquake-resistant buildings.
- Secure heavy furniture and appliances.
- Keep an emergency kit ready.
- Learn “Drop, Cover and Hold” techniques.
- Stay away from windows and glass during earthquakes.
- Follow evacuation routes and safety instructions.
- Avoid panic and move to open areas after shaking stops.
Question 11.
Prepare a map showing landform-associated disasters that happened in the current calendar year.
Answer:
Do it yourself.
Question 12.
Create a poster showing landforms that are considered sacred or important in your region, and add the folk stories associated with them.
Answer:
Do it yourself.
Question 13.
Document a case of a disaster that hit your region in the past, highlighting its effects on various human activities.
Answer:
Do it yourself.
Question 14.
Translate the given poster on landslide into your native language and display it in your home.
Answer:
Do it yourself.
Question 15.
Divide the class into three groups. Each group will work on one project (water, wind, and glacier). The project should highlight the causes, impact on human life and the environment, and mitigation measures.
Answer:
Do it yourself.