On December 2004, tsunami brought havoc on fourteen countries including India. Discuss the factors responsible for occurrence of tsunami and its effects on life and economy. In the light of guidelines of NDMA (2010) describe the mechanisms for preparedness to reduce the risk during such events.
Approach · directive: “discuss / describe”
What it asks · Explain what causes tsunamis, describe the 2004 impacts on people and the economy, and set out preparedness measures in line with NDMA's 2010 tsunami guidelines.
The question has 3 parts — answer each
- Discuss the factors responsible for the occurrence of a tsunami
- Discuss the 2004 tsunami's effects on life and the economy
- Describe the mechanisms of preparedness to reduce risk, in the light of the NDMA guidelines (2010)
Open with · The 26 December 2004 Indian Ocean tsunami, triggered by a great undersea earthquake off Sumatra, was among the deadliest disasters on record and exposed India's lack of a warning system.
Cover
- Causes: mostly undersea earthquakes at subduction zones where one plate is thrust under another; also underwater landslides, volcanic eruptions and, rarely, meteorite impact.
- Amplification: shallow coasts, funnel-shaped bays and the loss of mangroves and coastal dunes raise wave height on landing.
- Effects on life: over ten thousand died in India, mostly in Tamil Nadu, the Andaman and Nicobar Islands, Andhra Pradesh, Kerala and Puducherry; many lost their homes.
- Effects on the economy: fishing boats, ports, homes, roads and farmland were destroyed, and salt water damaged soil; livelihoods took years to recover.
- Preparedness (warning): a tsunami early warning system with seismic and sea-level sensors and quick alerts to coasts, run by INCOIS Hyderabad.
- Preparedness (risk reduction): hazard and vulnerability mapping, coastal land-use control, bio-shields such as mangroves, safe structures, evacuation shelters and routes.
- Preparedness (community): public awareness, mock drills, trained responders, clear roles for agencies, and coordination through the National and State Disaster Management Authorities.
Close with · Since 2004 India has built a warning system; preparedness now depends on community awareness, safe coastal planning and regular drills.
Question: UPSC's CS (Main) 2017, GS Paper III — paper ↗. Approach: Minimalist IAS, checked 30 Sept 2026 (how we verify) — UPSC publishes no model answers. ·
Model answer · 351 words (UPSC limit 250) · Minimalist IAS
On 26 December 2004 a great earthquake off Sumatra sent a tsunami across the Indian Ocean; India, with no warning system, lost more than ten thousand lives on its eastern coast and islands.
Why tsunamis occur
- Subduction earthquakes: most tsunamis follow shallow, high-magnitude quakes where one plate is thrust under another and the seabed is suddenly lifted, displacing the whole water column; the 2004 event occurred at the boundary of the Indian and Burma plates.
- Other triggers: submarine landslides, volcanic collapse (Krakatoa, 1883) and, rarely, meteorite impact.
- Amplification on arrival: waves slow and rise in shallow water; funnel-shaped bays, flat low coasts and the loss of mangroves and dunes let them run far inland.
- India's exposure: the Andaman-Sumatra arc in the east and the Makran zone in the Arabian Sea.
Effects on life and economy
- Life: deaths concentrated in Tamil Nadu, with Nagapattinam worst hit, the Andaman and Nicobar Islands, Andhra Pradesh, Kerala and Puducherry; fishing villages wiped out, families displaced for years, and women and children disproportionately among the dead.
- Economy: boats, nets and harbours destroyed, ending fishing incomes overnight; ports, roads, power lines and the Car Nicobar air base damaged; farmland and wells salinised; tourism collapsed and rebuilding absorbed public funds for years.
Preparedness under NDMA guidelines (2010)
- Early warning: the Indian Tsunami Early Warning Centre at INCOIS, Hyderabad, links seismic stations, bottom-pressure recorders and tide gauges to issue alerts within minutes; last-mile dissemination by siren, radio, SMS and local officials.
- Risk assessment and land use: inundation and vulnerability maps for every coastal district; coastal zoning, setback lines and tsunami-resistant building codes; elevated shelters and vertical evacuation in dense areas.
- Bio-shields: mangroves, casuarina belts and dune restoration along exposed coasts.
- Community readiness: awareness campaigns, school curricula, mock drills, marked evacuation routes and trained village response teams.
- Institutions: clear roles for NDMA, State and district authorities under the Disaster Management Act 2005, NDRF battalions on the coast, hospital preparedness and periodic review of plans.
India now has the warning system it lacked in 2004; what remains is to make coastal communities, buildings and land use as ready as the sensors.
Written by Minimalist IAS from facts checked at source (how we verify) — a little fuller than exam length, so every part of the question is covered; in the hall, keep the structure and trim the detail. UPSC publishes no model answers: compare your structure and coverage with this, then write your own.