Ocean Resources
Short Questions
1. What is the continental shelf?
Answer: The continental shelf is the submerged, shallow portion of continents bordering coastal areas, up to 180–200 m deep.
2. Why is fishing developed on continental shelves?
Answer: Sunlight penetration supports plankton growth, making continental shelves rich in fish.
3. What is the depth range of the continental slope?
Answer: The continental slope extends from 200 m to 4000 m deep.
4. What are abyssal plains?
Answer: Abyssal plains are vast, gently sloping plains covering ~66% of the ocean floor.
5. What is the deepest part of the ocean?
Answer: Oceanic trenches, like the Mariana Trench (~11 km), are the deepest parts.
6. What are oceanic ridges?
Answer: Oceanic ridges are submerged mountain ranges on the ocean floor.
7. Name a coral island in the Indian Ocean.
Answer: Aldabra Islands are coral islands in the Indian Ocean.
8. What are manganese nodules?
Answer: Manganese nodules are mineral deposits on abyssal plains containing iron, nickel, cobalt, and copper.
9. What is the primary source of tidal energy?
Answer: Tidal energy is generated from the movement of tides.
10. What is desalination?
Answer: Desalination is the process of removing salt from seawater to make it potable.
11. Which ocean route is the busiest for trade?
Answer: The Atlantic Ocean route is the busiest for maritime trade.
12. What is the EEZ?
Answer: The Exclusive Economic Zone (EEZ) extends 200 nautical miles from a country’s coast for resource exploitation.
13. What is a major source of marine pollution?
Answer: Oil spills from ships and coastal extraction are major sources of marine pollution.
14. What is the Great Barrier Reef?
Answer: The Great Barrier Reef is the world’s largest coral reef, off Australia’s northeast coast.
15. Who regulates international ocean resources?
Answer: International institutions regulate ocean resources beyond the EEZ.
Long Questions
1. Why are continental shelves considered economically important?
Answer: Continental shelves are economically vital due to their rich fishing grounds, supported by plankton growth from sunlight penetration. They also contain significant oil and gas reserves, like Mumbai High, and minerals such as diamonds and phosphorite. These resources support industries like fisheries, energy, and mining, boosting coastal economies.
2. Why is knowledge of oceanic trenches limited?
Answer: Oceanic trenches, like the Mariana Trench (~11 km deep), are difficult to explore due to their extreme depth and high-pressure environments. Only three humans have visited below 6000 m, and exploration relies on limited 1950s sampling campaigns. Advanced technology is needed to overcome these challenges and expand our understanding.
3. How do oceans contribute to energy production?
Answer: Oceans generate energy through tidal power, harnessing tide movements, as seen in the Bay of Fundy’s turbine powering 500 homes. Thermal energy uses temperature differences between surface and deep water to produce electricity, with trials in Belgium and Cuba. These renewable sources reduce reliance on fossil fuels but face technological and cost barriers.
4. What are the environmental challenges of desalination?
Answer: Desalination, while providing potable water, harms marine life by sucking in plankton and baby fish, disrupting food chains. The process is energy-intensive and costly, limiting its use in developing countries. Waste brine disposal further pollutes oceans, necessitating eco-friendly methods to mitigate impacts.
5. How do oceans facilitate global trade and transport?
Answer: Oceans provide the cheapest mode of transport via maritime routes, with the Atlantic Ocean route being the busiest, connecting North America and Western Europe. Ships carry cargo and people efficiently across vast distances. This supports global trade, fostering economic ties between industrialized regions.
6. What is the significance of the Law of the Sea (UNCLOS 1982)?
Answer: The UNCLOS (1982) defines a country’s territorial sea (12 nautical miles) and EEZ (200 nautical miles) for resource rights. Beyond the EEZ, resources are international, regulated by global institutions. This framework balances national exploitation with global cooperation for sustainable ocean use.
7. How does marine pollution threaten human well-being?
Answer: Marine pollution, from oil spills and plastics, contaminates seafood, posing health risks to humans. It disrupts fisheries and tourism, threatening livelihoods and economies. As dependence on oceans grows, pollution could exacerbate food security issues by mid-21st century.
8. Why are coral reefs like the Great Barrier Reef ecologically important?
Answer: Coral reefs, like the Great Barrier Reef, support diverse marine ecosystems, hosting 400 coral types and numerous species. They provide food, habitats, and resources like pearls for medicine. However, pollution and tourism threaten their survival, necessitating conservation efforts.
9. How do oceanic landforms resemble terrestrial landforms?
Answer: Oceanic landforms like continental shelves (plains), trenches (valleys), and ridges (mountains) mirror terrestrial features. Submarine canyons and seamounts resemble terrestrial canyons and hills, formed by similar tectonic and erosional processes. This similarity aids in applying geological knowledge to ocean exploration.
10. What measures can ensure sustainable oceanic tourism?
Answer: Oceanic tourism, like scuba diving and cruises, should adopt eco-friendly practices, such as limiting waste and using biodegradable materials. Marine protected areas around coral reefs can restrict harmful activities while allowing educational tourism. Regular monitoring and public awareness campaigns ensure minimal disturbance to marine ecosystems.
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