Lesson 2.1: Physical Geography – Earth, Atmosphere, Climate, Natural Disasters
Physical Geography studies the Earth’s structure, atmosphere, climate patterns, and natural hazards. It forms the foundation for understanding Indian and World Geography in UPSC.
Earth:
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Structure: Crust, mantle, core; lithosphere and tectonic plates.
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Landforms: Mountains, plateaus, plains, valleys.
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Rocks & Minerals: Igneous, sedimentary, metamorphic; mineral distribution in India.
Atmosphere:
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Layers: Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere.
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Weather vs Climate: Weather is short-term; Climate is long-term patterns.
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Air Circulation: Winds, monsoon patterns, jet streams.
Climate:
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Factors influencing climate: Latitude, altitude, distance from sea, ocean currents, wind patterns.
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Types of climate: Tropical, Arid, Temperate, Polar.
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Indian Monsoon: Southwest and Northeast monsoons, onset, withdrawal, impact on agriculture.
Natural Disasters:
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Earthquakes – Causes, fault lines (Himalayan, Indo-Gangetic), Richter scale.
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Volcanoes – Types, examples (Andaman, Barren Island).
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Cyclones & Tsunamis – Formation, impact on coastal regions.
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Floods & Droughts – Causes, preventive measures.
Key Points for Revision:
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Layers of Earth and Atmosphere
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Factors affecting climate and monsoon patterns
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Major natural disasters in India and their causes
Example Question (Prelims Practice):
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“Which layer of the atmosphere contains the ozone layer?” → Stratosphere
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“Which island in India has an active volcano?” → Barren Island
