CLAT– Geography

Universe & Solar System

Universe = all celestial matter; study: Astronomy (bodies), Cosmology (origin)
Big-Bang Theory: accepted origin model
Galaxy types: Spiral, Elliptical, Irregular; Milky Way (spiral) ⇢ our solar neighbourhood
Solar System: Sun + 8 planets, dwarf bodies, asteroids, comets
- Inner planets: Mercury, Venus, Earth, Mars; outer: Jupiter, Saturn, Uranus, Neptune
- Sun–Earth mean distance 1.5\times10^{8}\,\text{km} → light in 8.3\,\text{min}
- Key planet facts: Jupiter (largest), Mercury (smallest), Venus (brightest & hottest, Earth’s twin), Mars (red), Neptune (coldest & farthest)
- Titan = only satellite with dense atmosphere

Earth: Shape, Motions & Position

Shape: Geoid; measured by Geodesy
Rotation: W→E; 23^{\circ}56'04'' ≈ 24\,h → day/night
Revolution: 365 days along elliptical orbit; axial tilt 23.5^{\circ} causes seasons
Key dates: Spring 21\,Mar, Summer solstice 21\,Jun, Autumn 23\,Sep, Winter 22\,Dec
Perihelion 3\,Jan (nearest 147\,\text{M km}); Aphelion 4\,Jul (farthest 152\,\text{M km})
Moon: Perigee (nearest), Apogee (farthest); Solar eclipse (New Moon), Lunar eclipse (Full Moon)

Geographic Coordinates & Time

Latitudes (0–90^{\circ} N/S); important: Equator 0^{\circ}, Tropics 23.5^{\circ}, Polar circles 66.5^{\circ}
Longitudes 0–360^{\circ}; Prime Meridian 0^{\circ}, International Date Line 180^{\circ}
Crossing IDL: east → -1 day, west → +1 day
Time zones: 15^{\circ}=1 hour; IST 82.5^{\circ}E = GMT +5:30

Interior & Rocks

Layers: Crust (Sial), Mantle (Sima), Core (Nife)
Rock types: Igneous (granite), Sedimentary (sandstone), Metamorphic (marble)
Crust composition: \text{O}_2 46\% (max), Mg 1.5\% (min)

Atmosphere Essentials

Major gases: \text{N}2 78\%, \text{O}2 21\%, Ar 0.93\%, \text{CO}_2 0.3\%
Layers (bottom→top): Troposphere (weather), Stratosphere (ozone), Mesosphere (coldest), Ionosphere (radio), Exosphere
Greenhouse gases: Water vapour, \text{CO}2, Methane, \text{N}2\text{O}, Ozone

Natural Hazards

Earthquake focus (hypocentre) & epicentre; magnitude: Richter 0–9; study: Seismology
Volcano types: Active, Dormant, Extinct; 68\% in Pacific Ring of Fire

Landforms & Continents

7 continents; Asia: largest; Africa: only one in all 4 hemispheres; Antarctica: “white continent”
Major mountain ranges: Andes (longest), Himalaya (youngest; Everest 8848\,m)
Plateaus: Tibetan (highest, “roof of world”), Deccan (India)
Deserts: Antarctica (largest cold), Sahara (largest hot)
Grasslands names: Prairies (N-America), Pampas (S-America), Steppes (Eurasia), Savanna (Africa), Downs (Australia), Velds (S-Africa)

Hydrosphere & Water Bodies

Water distribution: Oceans 97.25\%, Ice 2.05\%, Groundwater 0.68\%
Oceans: Pacific (largest/deepest), Atlantic (busy trade), Indian (only named after a country), Arctic (smallest/least saline)
Deepest point: Mariana Trench (Pacific)
Lakes: Baikal (deepest), Tanganyika (longest), Titicaca (highest navigable), Dead Sea (lowest)
Important straits: Bering, Gibraltar, Malacca, Palk, Bab-el-Mandeb

Winds, Currents & Tides

Planetary winds: Trade 0–30^{\circ}, Westerlies 30–60^{\circ}, Polar Easterlies 60–90^{\circ}
Ocean currents: clockwise N-hemisphere, anticlockwise S-hemisphere; e.g., Gulf Stream (warm), Oyashio (cold)
Tides: Spring (Sun–Moon–Earth aligned, highest), Neap (right angle, lowest)
Tropical cyclones naming: Hurricane (Atlantic), Typhoon (W-Pacific), Willy-Willy (Australia)

India: Size & Position

Area rank: 7^{\text{th}}; 2.42\% of world area
Lat 8^{\circ}04'N–37^{\circ}06'N; Long 68^{\circ}07'E–97^{\circ}25'E
Tropic of Cancer 23^{\circ}30'N passes 8 states; land boundary \approx15\,200\,\text{km}; coastline 7\,516.6\,\text{km}
Neighbours 7: Bangladesh (longest 4097\,km) > China > Pakistan > Nepal > Myanmar > Bhutan > Afghanistan
Southernmost: Indira Point; northernmost: Indira Col

Major Physiographic Divisions (India)

Northern & N-Eastern Mountains (Himalaya + Purvanchal)
Northern Plains (alluvial; Bhabar → Terai → Bhangar → Khadar)
Peninsular Plateau (Central Highlands, Deccan; Ghats meet at Nilgiri)
Indian Desert (Thar; Luni river)
Coastal Plains (Western: Konkan–Malabar; Eastern: Northern Circars–Coromandel)
Islands: Andaman–Nicobar (10° Channel), Lakshadweep (9° & 8° Channels)

Drainage (India)

Himalayan: Indus, Ganga, Brahmaputra systems
Peninsular: Godavari (longest), Krishna, Mahanadi, Cauvery, Narmada & Tapti (west-flowing rift rivers)
Largest delta: Sundarbans (Ganga-Brahmaputra)

Climate & Vegetation (India)

Type: Tropical Monsoon; SW monsoon Jun–Sep (~120 days), NE monsoon Oct–Dec (Tamil Nadu)
El Niño (warm Pacific) ↔ weak monsoon; La Niña ↔ heavy monsoon
Forest types: Tropical Evergreen, Moist/Dry Deciduous (widest), Thorn, Montane, Mangrove (Sundarbans)
Forest cover 24.56\% (2019); highest %: Mizoram; max gain: Karnataka

Soils & Agriculture

Soil–crop links: Alluvial (rice, wheat), Black/Regur (cotton), Red (millets, pulses), Laterite (tea, coffee), Arid (barley)
Crop seasons: Kharif (Jun–Oct), Rabi (Nov–Mar), Zaid (Apr–Jun)
Green Revolution (post 1968): HYV seeds, irrigation, fertilisers; Father in India: Norman Borlaug

Minerals & Energy (India)

Coal: Jharkhand lead; Petroleum: Mumbai High, Assam, KG Basin; Natural Gas: western offshore, Assam
Metallic: Iron (Odisha/Jharkhand), Manganese (Odisha), Bauxite (MP), Copper (MP)
Power: Thermal \approx65\%, Hydel (Himalayan rivers), Nuclear (Tarapur, Kudankulam, Kalpakkam)

Transport Infrastructure

Rail: 4th largest; longest route “Vivek Express” 4273\,km; longest platform Gorakhpur \approx1.3\,km
13 major ports: Kandla, Mumbai, JNPT, Mormugao, Mangalore, Kochi, Paradip, Visakhapatnam, Chennai, Ennore, Tuticorin, Port Blair, Enayam (proposed)
Major canals: Panama (Pacific–Caribbean), Suez (Mediterranean–Red), Kiel (Baltic–North)
National Waterways: NW-1 (Allahabad–Haldia 1620\,km) largest

Environment & Conservation

Pollution types: Air, Water, Noise, Radioactive, Solid waste; key greenhouse gases: \text{CO}2, \text{CH}4
Biodiversity hotspots in India: Western Ghats, Eastern Himalaya
Protected areas: 18 Biosphere Reserves (e.g., Nilgiri, Sundarbans), 166 National Parks (1st: Jim Corbett), 515 Wildlife Sanctuaries
Flagship species: Tiger & Lion (only country with both)

Quick Superlatives

Highest peak (world): Everest 8848\,m; India: Kanchenjunga 8598\,m
Longest river (world): Nile 6690\,km; India: Ganga 2525\,km within country length
Largest lake (world): Caspian Sea; deepest: Baikal 1637\,m
Largest delta: Sundarbans \sim10^{4}\,\text{km}^2
Largest plateau: Tibetan; largest desert: Antarctica; largest coral reef: Great Barrier (Australia)