Geophysical Phenomena and Changes in Geographical Features

What the official syllabus says

UPSC Civil Services (Main) Examination, Paper II: General Studies I.

Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., geographical features and their location-changes in critical geographical features (including water-bodies and ice-caps) and in flora and fauna and the effects of such changes.

Topics in detail

Earthquakes

• Focus and epicentre; P, S and surface waves
• Measuring earthquakes: magnitude and intensity scales
• Causes: plate movements, faults, volcanic activity, reservoir-induced
• World distribution: the circum-Pacific belt and the Alpine–Himalayan belt
• Seismic zones of India

Tsunamis

• Causes: undersea earthquakes, landslides, volcanic eruptions
• The Indian Ocean tsunami of 2004; warning systems

Volcanoes

• Types of volcanoes and eruptions; volcanic landforms
• World distribution: the Ring of Fire, mid-ocean ridges, hotspots
• Volcanoes of India: Barren Island and Narcondam
• Effects on climate and people

Cyclones and other hazards

• Tropical cyclones: conditions of formation, structure, regional names, naming of cyclones in the North Indian Ocean
• Temperate cyclones and anticyclones
• Thunderstorms, tornadoes, cloudbursts, heatwaves and cold waves
• Landslides, avalanches, floods and droughts

Geographical features and their location

• Mapping skills: oceans, seas, straits, gulfs, islands, mountain ranges, passes, rivers, lakes, deserts, grasslands, plateaus
• Places in the news located on the map
• India’s neighbourhood: borders, rivers and mountain passes

Changes in critical geographical features

• Ice-caps and glaciers: retreat of Himalayan glaciers, Arctic sea-ice loss, the Greenland and Antarctic ice sheets
• Water bodies: shrinking lakes (the Aral Sea, Lake Chad), wetlands, changing river courses, sea-level rise
• Coastlines: erosion, deltas and islands at risk (the Sundarbans)
• Deserts: desertification and land degradation
• Permafrost thaw

Changes in flora and fauna

• Shifts in species’ ranges and seasons
• Coral bleaching, invasive species, loss of habitat
• Extinction and threatened species

Effects of such changes

• On water security, agriculture, coasts, health and livelihoods
• Migration and conflict
• Responses: adaptation, early warning, conservation

Overlaps

• Disaster management and environment are in General Studies III.