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Class 9 · Social ScienceNCERT 2026 Revised Syllabus

Chapter 1: Oceans and Life (0908CH01)

Understanding Society Part II

Explores the oceans, their physical features, movements, resources, maritime zones and the importance of international rules for safe and sustainable use.

Chapter code: 0908ch01 · Book: Understanding Society Part II · Class 9 Social Science

Find complete NCERT solutions for Class 9 Social Science, Understanding Society Part II Chapter 1. Every question has a clear, step-by-step answer for chapter code 0908CH01.

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QUESTIONS AND ACTIVITIES(9 questions)

1

How do different features of the ocean floor affect human activities such as fishing, transport, and underwater exploration?

Ans.
The ocean floor has several physical features that influence human activities: 1. Continental shelves are shallow, sunlit areas rich in nutrients and marine life. They support fishing and often contain petroleum and natural gas deposits. 2. Continental slopes descend steeply into deeper oceans and make seabed exploration and construction more difficult. 3. Deep-sea plains provide relatively level areas, while ocean ridges and seamounts influence currents and create habitats for marine organisms. 4. Ocean trenches are extremely deep and difficult to explore because of immense water pressure. 5. Underwater cables and pipelines must be planned according to the relief of the seabed. Thus, ocean-floor features affect fishing grounds, navigation, resource extraction and scientific exploration.
2

How do waves, tides, and ocean currents influence climate, marine life, and human activities around the world?

Ans.
1. Waves mix surface water, distribute oxygen and nutrients, shape coastlines and influence coastal activities. Very high waves and storm surges can damage settlements and ports. 2. Tides cause the regular rise and fall of sea level. They support tidal ecosystems, help flush estuaries and can be used to generate tidal energy. They also affect the timing of navigation and fishing. 3. Ocean currents transport warm and cold water. Warm currents can make nearby coastal regions milder, while cold currents may cool them and encourage fog. 4. Currents redistribute heat around the planet and influence rainfall, weather and climate. 5. Currents also transport nutrients and plankton, affecting marine food chains and fishing grounds. Ships use favourable currents where possible, while fishers and coastal communities plan activities around sea conditions.
3

Describe the importance of marine resources.

Ans.
Marine resources are important in several ways: 1. Food: Fish, prawns, crabs, seaweed and other organisms provide nutrition and support food security. 2. Livelihoods: Fishing, aquaculture, shipping, tourism and port activities employ millions of people. 3. Minerals and energy: Oceans contain salt, sand, minerals, petroleum and natural gas; offshore wind, tidal and wave energy also offer renewable possibilities. 4. Trade and transport: Sea routes carry a large share of international cargo and connect countries. 5. Medicines and research: Marine organisms provide substances useful in medical research and biotechnology. 6. Climate regulation: Oceans absorb and store heat and carbon dioxide and help regulate the global climate. These resources must be used sustainably to prevent pollution, habitat destruction and overfishing.
4
Hard

Draw a poster that encourages people to protect marine resources. Include a slogan (like Save Our Seas or Fish for the Future) and explain your message in 2–3 sentences.

Ans.
Poster text:SAVE OUR SEAS — EVERY DROP OF ACTION COUNTS!Say NO to plastic pollution • Choose sustainable seafood • Protect coral reefs • Keep beaches cleanMessage: Oceans provide food, livelihoods, biodiversity and climate regulation, but pollution and overfishing threaten them. By reducing single-use plastic, disposing of waste responsibly and supporting sustainable fishing, each of us can help keep marine ecosystems healthy for future generations.
5
Hard

Using a map of India, mark at least five coastal states that might need tsunami warnings.

Ans.
On an outline map of India, mark and label these coastal states: Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Odisha and West Bengal. Any five or more are acceptable. The Andaman and Nicobar Islands should also be marked as a Union Territory. All coastal regions may require tsunami preparedness; the east coast and island regions are particularly exposed to tsunami hazards arising from seismic activity in the Indian Ocean and adjoining tectonic zones.
6
Hard

Work in a group and act out what would happen when a cyclone warning is issued. Highlight what role different people, like scientists, officials, and coastal villagers, would play.

Ans.
Model response — cyclone warning and community action: 1. Scientists at the India Meteorological Department monitor satellite images, sea conditions and wind patterns, forecast the cyclone's path and issue warnings. 2. Disaster-management authorities and district officials communicate alerts through television, radio, mobile messages, sirens and local volunteers. They identify vulnerable areas and arrange evacuation, shelters, food, drinking water and medical help. 3. Police, rescue teams and local administration guide people to safe shelters, keep roads clear and assist children, older persons and persons with disabilities. 4. Coastal villagers secure boats, switch off electricity where advised, carry essential medicines and documents, and move to designated shelters. They do not go to the shore to watch the storm. 5. After the cyclone, officials assess damage, restore essential services and organise relief, while residents follow safety instructions and report urgent needs. Conclusion: Timely scientific warnings, coordinated administration and public cooperation reduce loss of life and property.
7
Hard

Suppose a foreign ship is sailing through India’s territorial sea. What principle allows the ship to pass through these waters, subject to certain conditions?

Ans.
The principle is innocent passage under the law of the sea. A foreign ship may pass continuously and expeditiously through India's territorial sea, provided its passage is not prejudicial to India's peace, good order or security. It must obey applicable laws and must not engage in activities such as fishing, weapons exercises, spying or pollution.
8
Hard

A country has an Exclusive Economic Zone (EEZ) extending up to 200 nautical miles from its baseline. What rights does the country have over the natural resources in this zone?

Ans.
Within its EEZ, a coastal country has sovereign rights to explore, exploit, conserve and manage natural resources of the waters, seabed and subsoil. These include fish, other living resources, petroleum, natural gas and minerals. It may regulate activities such as fishing and offshore resource extraction and has jurisdiction over artificial islands, marine scientific research and protection of the marine environment. The EEZ is not the same as territorial waters: other countries retain freedoms such as navigation and overflight, subject to international law.
9
Hard

Create a model of an ocean with ship routes, protected zones, and safety measures. Based on the model, explain how it follows maritime laws and protects the ocean.

  1. a.Build a model showing the ocean and its main zones.
  2. b.Include ship routes, protected zones and safety measures.
  3. c.Explain how the model follows maritime laws and helps protect the ocean.
Ans.
Model description: Make a base showing the coastline, baseline, territorial sea, EEZ and high seas. Mark a clearly defined shipping lane, a port, a lighthouse, a marine protected area and a fishing zone. Add symbols for a no-dumping rule, speed limits near sensitive habitats, life-saving equipment, emergency communication and oil-spill response.Explanation: The marked shipping lane keeps vessels on a safe route and reduces collision risk. Ships must follow navigation and safety rules, maintain pollution-control systems and avoid discharging waste. Fishing is regulated to prevent overexploitation, while the protected area safeguards breeding grounds and biodiversity. The territorial sea and EEZ are labelled according to maritime law, and foreign vessels' lawful navigation rights are respected. The model therefore combines safe navigation, sustainable resource use and marine conservation.

THE BIG QUESTIONS — Chapter overview (Textbook p. 1)(5 questions)

BQ1

What is the importance of ocean relief?

Ans.
Ocean relief refers to the varied features of the ocean floor, such as continental shelves, slopes, abyssal plains, ridges, seamounts and trenches. These landforms create different habitats and influence the distribution of marine organisms and resources. Shallow continental shelves support rich fisheries and may contain oil and gas. Slopes, ridges and trenches affect seabed movement, currents and the difficulty of exploration. Knowledge of relief is essential for safe navigation, laying cables and pipelines, locating resources and protecting marine ecosystems.
BQ2

How does ocean water movement impact life and the environment?

Ans.
Waves erode and deposit materials along coastlines, forming beaches, caves, arches and other landforms. Tides raise and lower sea levels, influencing fishing, harbour access and coastal habitats; tidal movements can also generate electricity. Ocean currents transport warm and cold water, redistribute heat, influence rainfall and coastal temperatures, and carry nutrients that support plankton and fish. Together, these movements shape marine ecosystems, climate, transport and coastal livelihoods.
BQ3

Why are maritime zones important for a country?

Ans.
Maritime zones establish the extent of a coastal State’s authority under international law. In its territorial sea, a State exercises sovereignty subject to rules such as innocent passage. In the contiguous zone it may enforce specified customs, immigration, fiscal and sanitary laws. In its Exclusive Economic Zone (EEZ), it has sovereign rights to explore, exploit, conserve and manage natural resources, while other States retain specified freedoms such as navigation and overflight. Clear zones reduce disputes, support resource management, protect the marine environment and help regulate safe international movement.
BQ4

How can we use ocean resources in a sustainable way?

Ans.
Sustainable use means meeting present needs without damaging the ability of future generations to benefit from the oceans. Important measures include regulating fishing and preventing overfishing; protecting coral reefs, mangroves and breeding grounds; reducing plastics, sewage, oil and chemical pollution; using marine minerals and energy responsibly; following maritime law; supporting coastal communities and traditional knowledge; and monitoring ecosystems scientifically. The Blue Economy links economic growth and livelihoods with the long-term health of marine ecosystems.
BQ5

How do early warning systems help protect people from tsunamis and cyclones?

Ans.
Early warning systems combine scientific monitoring, forecasting, communication and community preparedness. Seismic stations detect undersea earthquakes; ocean-bottom pressure recorders and tide gauges help confirm and track tsunami waves. Satellites, radar, ocean observations and weather models help forecast cyclones and storm surges. Warning centres transmit alerts to governments, emergency services and the public through mobile messages, radio, television, sirens and other channels. Training, evacuation routes, shelters and public awareness turn warnings into life-saving action.

IN-TEXT QUESTIONS AND ACTIVITIES — Chapter 1 (Textbook pp. 3–18)(11 questions)

p. 3
Hard

Looking at Fig. 1.2, answer the following questions.

  1. a.How do you think these oceanic features would have been formed?
  2. b.Which part of the ocean floor appears deep and shallow?
  3. c.How do you think these underwater features would have an effect on marine life and ocean movements?
Ans.
1. How the features form: Continental shelves and slopes are the submerged edges of continents. Mid-ocean ridges form where tectonic plates move apart and magma rises and cools. Trenches form at subduction zones where one plate sinks beneath another. Seamounts are commonly volcanic; wave action may flatten their summits to form guyots. Abyssal plains become smooth through the accumulation of fine sediments. 2. Deep and shallow areas: Continental shelves are relatively shallow. Continental slopes descend to deeper water; abyssal plains are very deep and broad, while trenches are the deepest features. Ridges and seamounts rise above the surrounding seabed. 3. Effects: Shelves receive sunlight and nutrients and support productive fisheries. Ridges, seamounts and trenches provide specialised habitats. Relief can redirect currents, influence mixing and affect the location of nutrients and marine organisms.
p. 4
Hard

Observe Fig. 1.3 and Fig. 1.4. Identify a wave’s crest and trough, and describe the sequence of erosional landforms shown, including the original headland.

  1. a.What are the crests and troughs in a wave?
  2. b.How do wave actions create the erosional landforms shown in Fig. 1.4?
  3. c.What is the original headland?
Ans.
In Fig. 1.3, the crest is the highest part of a wave and the trough is the lowest part between two crests. In Fig. 1.4, waves repeatedly attack weaknesses in a rocky headland. Cracks may widen into sea caves; continued erosion can cut through a headland to form an arch. When the arch roof collapses, an isolated sea stack remains. Further erosion and weathering may reduce the stack to a low stump. A headland is a piece of land that projects out into the sea. Beaches are depositional landforms, not part of this erosional sequence.
p. 5

Find the names of some famous sea beaches in India and locate them on a map of India.

  1. a.Find names of famous sea beaches in India.
  2. b.Locate and label the selected beaches on a map of India.
Ans.
On an outline map of India, mark and label a selection of well-known beaches. Suitable examples are: Marina Beach—Chennai, Tamil Nadu; Puri Beach—Odisha; Kovalam—Kerala; Calangute or Baga—Goa; Juhu—Mumbai, Maharashtra; Radhanagar Beach—Swaraj Dweep, Andaman and Nicobar Islands; and Digha—West Bengal. Add a title, north arrow and a simple legend. The list is illustrative; any correctly located Indian sea beach is acceptable.
p. 5

Observe Fig. 1.5 and describe the change in water level during high and low tides.

  1. a.Observe Fig. 1.5.
  2. b.Describe how the water level changes during high tide.
  3. c.Describe how the water level changes during low tide.
Ans.
The diagram shows tidal water bulging on opposite sides of the Earth. At high tide, the sea reaches a higher level and advances farther over the coast. At low tide, the water level falls and the shoreline retreats, exposing parts of the seabed. The regular change is mainly caused by the gravitational pull of the Moon and, to a lesser extent, the Sun, together with the Earth–Moon system’s motion.
p. 7

Observe Fig. 1.7. How do high and low tides influence fishing activities?

  1. a.Observe Fig. 1.7.
  2. b.Explain how high tides influence fishing activities.
  3. c.Explain how low tides influence fishing activities.
Ans.
During high tide, rising water allows many fish to move closer to the shore in search of food and shelter. Fishers can use this movement and their knowledge of local tidal timings to plan fishing activities and may obtain a better catch. Tides also change the depth and accessibility of coastal waters, so fishers need to consider tidal conditions for safety. The figure’s main point is that high tides can bring fish nearer to the shore.
p. 8

Observe the map of warm and cold ocean currents. Do these currents affect the temperature of nearby coastal regions?

  1. a.Observe the map of warm and cold ocean currents.
  2. b.Explain whether these currents affect the temperature of nearby coastal regions.
Ans.
Warm currents transport water from lower latitudes and can make nearby coastal areas milder and warmer. The Gulf Stream, for example, helps keep parts of north-western Europe relatively mild. Cold currents carry water from higher latitudes and cool nearby coasts; the Labrador Current contributes to colder conditions and sea ice along parts of eastern Canada. Currents also influence humidity, fog, rainfall and marine productivity, although local climate is affected by several factors.
p. 8

Observe Fig. 1.9 and note the ocean currents along the coastline of India. What is the nature of these currents?

  1. a.Observe Fig. 1.9.
  2. b.Identify the ocean currents shown along the coastline of India.
  3. c.Describe the nature or direction of these currents.
Ans.
The surface-current pattern around India changes with the monsoon. During the south-west monsoon, strong winds drive currents in a different direction from those during the north-east monsoon; therefore, the circulation in the Arabian Sea and Bay of Bengal shows a seasonal reversal. Currents also vary with the coastline, temperature, salinity and the wider Indian Ocean circulation. For the map activity, trace the arrows shown in Fig. 1.9 and label the currents as warm or cold only where the map or reliable atlas identifies them.
p. 9–10

The people of Simeulue were partly protected during the 2004 tsunami by local folklore. Find out whether similar traditional stories or practices related to natural disasters exist in your culture, and explain how traditional knowledge can help keep communities safe.

  1. a.Find out whether communities in India or elsewhere have traditions or stories that warn people about tsunamis or other coastal hazards.
  2. b.Describe the tradition and explain how it can help people respond to danger.
Ans.
Model response: In many coastal communities, elders pass down stories about unusual natural signs and the need to move away from the shore when the sea suddenly withdraws or the ground shakes strongly. Such knowledge can alert people before official warnings reach them. It should complement, not replace, scientific alerts and evacuation instructions. Families should learn safe routes, practise evacuation and share reliable information with neighbours. Replace this example with a story or practice actually reported by elders in your community.
p. 14

If you receive a tsunami or cyclone alert on your phone, what five steps should your family take to stay safe?

  1. a.State five practical steps your family should take after receiving a tsunami or cyclone alert on a phone.
Ans.
1. Read the alert carefully and follow instructions from the district administration and disaster-management authorities. 2. Move immediately to a designated cyclone shelter or to higher ground and inland areas for a tsunami; do not go to the beach to watch the waves. 3. Carry an emergency kit containing drinking water, essential medicines, a torch, a charged phone, basic food and important documents in a waterproof pouch. 4. Help children, older persons and people with disabilities, and keep family members informed through a planned contact method. 5. Stay away from floodwater, damaged wires and the coast; return home only after authorities issue an official all-clear.
p. 16

Observe Fig. 1.20 and note the extent of India’s territorial sea in nautical miles.

  1. a.Observe Fig. 1.20.
  2. b.Identify the extent of India’s territorial sea shown in nautical miles.
Ans.
The territorial sea extends 12 nautical miles from the legally defined baseline. Within this zone, India exercises sovereignty over the water, seabed, subsoil and airspace, subject to international law, including the right of innocent passage for foreign ships. Do not confuse it with the contiguous zone, which extends up to 24 nautical miles from the baseline, or the Exclusive Economic Zone, which extends up to 200 nautical miles.
p. 18

Find examples of countries that have disagreements over territorial sea waters or maritime areas.

  1. a.Give examples of countries that have disagreements over territorial sea waters or other maritime areas.
  2. b.Briefly identify the disputed area or issue and explain why maritime boundaries matter.
Ans.
Examples commonly discussed in geography are the overlapping maritime claims involving China and the Philippines in parts of the South China Sea, and disagreements between Greece and Türkiye concerning parts of the Aegean and eastern Mediterranean. Such disputes may concern islands, maritime boundaries, fishing grounds, seabed resources or navigation. Countries use diplomacy, bilateral agreements, arbitration and international law, including the United Nations Convention on the Law of the Sea (UNCLOS), to resolve disputes peacefully. The exact status of a dispute should be checked from a current, reliable source before a class presentation.

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