Understand the Indian Ocean and you’ll understand much about Earth

Understand the Indian Ocean and you’ll understand much about Earth

Sub: Geography

Sec: Oceanography

Context:

• On World Oceans Day (June 8), the Indian Ocean is highlighted for its rapid warming and significant influence on global oceanic systems.
• Understanding the Indian Ocean is crucial for comprehending the Earth’s overall oceanic response to greenhouse gases and global warming.

Indian Ocean- Home to Deadly Storms:

• Known for dramatic monsoon winds and heavy rains, crucial for over a billion people in terms of water supply, fisheries, food, and energy.
• Experiences rapid warming in summer, especially in the Arabian Sea, Bay of Bengal, and southern tropical regions.
• The region faces pre-monsoon cyclones, which, though fewer in number compared to the Pacific and Atlantic, are deadly due to rapid intensification and impact on developing countries in South Asia, East Africa, and West Asia.
• Unique Geographical Configuration:
  • Northern boundary closed by the Asian landmass with small connections to the Persian Gulf and the Red Sea.
  • Southern boundary features oceanic tunnels connecting it to the Pacific and Southern Oceans.
    • Indonesian Throughflow: Transports significant water and heat from the Pacific into the eastern Indian Ocean, affecting circulation, temperature, and salinity.
    • Southern Ocean Connection: Allows colder, saltier waters to flow into the Indian Ocean below 1 km depth, mixing with Pacific waters and exiting southwards.
• Marine Life and Tourism:
  • Supports diverse fisheries including anchovies, mackerel, sardines, and tuna.
  • Attracts tourists for its dolphins, occasional whale sightings, popular beaches, and coral reefs from Lakshadweep to the Andaman-Nicobar Islands and Reunion Island.
• Role in Global Warming:
  • Despite heat from underwater tunnels, heavily influenced by atmospheric circulation from the Pacific.
  • Gains and must shed heat via waters moving south, with global warming adding extra heat from the Pacific and less cold water from the Southern Ocean.
  • Fastest warming ocean, affecting heat waves, extreme rain, corals, and fisheries.
  • Influences wind circulation, affecting the Pacific Ocean’s heat absorption and thus global warming control.
  • Helps accelerate heat sinking in the North Atlantic, modulating global warming.
• Historical Impact on Human Evolution:
  • Three million years ago, the northward drift of Australia and New Guinea separated the Indian and Pacific Oceans, changing East Africa’s climate from rainforest to savannah.
  • Hypothesized to have influenced human ancestors to develop bipedal movement for more efficient travel across distances.

Key facts about the Indian Ocean:

• Third-largest of the world’s five oceanic divisions, covering approx. 20% of the water on Earth’s surface.
• Bounded by Asia to the north, Africa to the west and Australia to the east.
• To the south, it is bounded by the Southern Ocean, or Antarctica, depending on the definition in use.
• Along its core, the Indian Ocean has large marginal, or regional seas, such as the Andaman Sea, the Arabian Sea, the Bay of Bengal, and the Laccadive Sea.
• It is named after India, which protrudes into it, and has been known by its current name since at least 1515.
• Previously, it was called the Eastern Ocean.
• It has an average depth of 3,741 m. All of the Indian Ocean is in the Eastern Hemisphere.
• Deepest point in the Indian Ocean: Sunda trench (Java trench)

Source: TH