UPSCNotes
Geography

Oceanography

UPSC notes on oceanography — ocean floor relief, temperature and salinity, waves and tides, ocean currents, El Niño, La Niña and the Indian Ocean Dipole.

SyllabusGS I · Salient features of world physical geography

Oceans cover about 71% of the Earth’s surface and store far more heat than the atmosphere. They move that heat from the tropics to the poles, feed moisture to the monsoon, and support fisheries and trade. UPSC treats oceanography as a link between physical geography, climate and the economy.

What UPSC asks

  • Prelims: ocean-floor features, warm and cold currents matched to oceans, salinity facts, tides, El Niño, La Niña and the Indian Ocean Dipole, and maritime zones.
  • Mains GS I: the factors that drive ocean currents and their effect on climate, fishing and trade; how ENSO and the IOD affect the Indian monsoon; the thermohaline circulation and climate change.

Key sub-topics

ThemeTopics
Ocean floorContinental shelf, slope and rise, abyssal plains, trenches, mid-ocean ridges, seamounts and guyots
Properties of sea waterTemperature, thermocline, salinity and its controls
MovementsWaves, tides (spring and neap), ocean currents and gyres
Ocean–atmosphere linksUpwelling, El Niño and La Niña, the Southern Oscillation, the Indian Ocean Dipole, thermohaline circulation
Resources and law of the seaFisheries, maritime zones under UNCLOS

Start with Ocean Currents, Temperature and Salinity.

Ocean Currents, Temperature and Salinity Ocean temperature and salinity, what drives currents, warm and cold currents, gyres, upwelling, ENSO, the IOD … Oceanography — Practice Questions UPSC Prelims-pattern practice questions on oceanography — ocean-floor relief, tides, currents, UNCLOS maritime … Oceanography — Quick Revision One-page UPSC revision of oceanography: ocean-floor relief, temperature, salinity, tides, warm and cold …