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.
It asks 3 things — 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 · On 26 December 2004 a Mw 9.3 Sumatra-Andaman earthquake displaced the seafloor and sent a tsunami across fourteen countries; in India 10,749 people died and 5,640 went missing (NDMA Guidelines, 2010), with no warning system in place.
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 · India now has the sensors it lacked in 2004; warnings become lives saved only when every exposed village earns UNESCO-IOC 'Tsunami Ready' recognition, which INCOIS now runs along India's coast.
Add value (verified)
- NDMA Guidelines on Management of Tsunamis (2010): in India 10,749 people lost their lives and 5,640 were missing in the 2004 tsunami.National Disaster Management Guidelines: Management of Tsunamis, NDMA, August 2010 (hosted by NIDM) ↗“In India 10,749 people lost their lives due to the tsunami and 5,640 people were missing in the Tsunami- affected areas.”
- NDMA Guidelines (2010): mock drills to be organised in each coastal district by the DDMA to assess deficiencies in response.National Disaster Management Guidelines: Management of Tsunamis, NDMA, August 2010 (hosted by NIDM) ↗“ll be organised in each coastal district by the concerned DDMA and the deficiencies in response, if any, will be assessed through mock drills.”
- NDMA on tsunami guidelines: a techno-legal regime through land-use practices, bioshields, shelter-belt plantation and mangrove regeneration with community involvement.NDMA: Tsunami (Natural Hazards page) ↗“recommends a robust techno-legal regime through efficient land use practices, bioshields, shelter belt plantation and mangrove regeneration with community involvement.”
- Indian Tsunami Early Warning System: 17 broadband seismic stations, 4 bottom pressure recorders, 25 tide gauges and a 24x7 warning centre.PIB: Working of Tsunami Warning System (Ministry of Earth Sciences) ↗“real-time seismic monitoring network of 17 broadband seismic stations to detect tsunamigenic earthquakes, a network of real-time sea-level sensors with 4 Bottom Pressure Recorders (BPR) in the open ocean and 25 tide gauge stations”
- INCOIS: the Indian Tsunami Early Warning Centre was set up at INCOIS, Hyderabad in response to the 2004 tsunami; INCOIS runs the UNESCO-IOC Tsunami Ready programme in India.INCOIS: Information on UNESCO-IOC Tsunami Ready Programme in India ↗“Information on UNESCO-IOC Tsunami Ready Programme in India In response to December 26, 2004 tsunami, government of India has established Indian Tsunami Early Warning Centre (ITEWC) at Indian National Centre for Ocean”
Question: UPSC's CS (Main) 2017, GS Paper III — paper ↗. Approach: Minimalist IAS, checked 3 Oct 2026 (how we verify) — UPSC publishes no model answers. ·
Model answer· 360words · Minimalist IAS
On 26 December 2004 a Mw 9.3 Sumatra-Andaman earthquake displaced the seafloor and sent a tsunami across fourteen countries. In India 10,749 people died and 5,640 went missing (NDMA Guidelines, 2010); there was no warning system that morning.
Factors responsible for the occurrence of tsunami
- Subduction earthquakes: shallow, high-magnitude quakes where one plate is thrust under another lift the seabed and displace the whole water column; the 2004 wave came from vertical slip on the inter-plate thrust fault.
- 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 coasts and lost 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 erased and families displaced for years.
- 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.
Mechanisms of preparedness under the NDMA Guidelines (2010)
- Early warning: the Indian Tsunami Early Warning Centre at INCOIS, Hyderabad (operational since October 2007) links 17 broadband seismic stations, 4 bottom pressure recorders and 25 tide gauges to a 24x7 centre; last-mile dissemination by siren, radio and SMS.
- Seismic detection
- INCOIS analysis
- Alert to States and districts
- Sirens, SMS, radio
- Evacuation to shelters
- Techno-legal regime: inundation and vulnerability maps for every coastal district; land-use control under coastal zoning, tsunami-resistant codes, elevated shelters and vertical evacuation structures.
- Bio-shields: mangrove regeneration and shelter-belt plantation with community involvement.
- Community readiness: public awareness, school education and mock drills in each coastal district by the DDMA to expose response gaps.
- Institutions: clear roles under the Disaster Management Act 2005, NDRF battalions on the coast, hospital preparedness and periodic review of plans.
India now has the sensors it lacked in 2004. Warnings become lives saved only when every exposed village earns UNESCO-IOC 'Tsunami Ready' recognition, which INCOIS now runs along India's coast.
Prepared by Minimalist IAS to the answer standard of Shivam Singh (mentor, 7 years) · facts checked against official sources (how we verify) · updated 3 Oct 2026. UPSC publishes no model answers: compare your structure and coverage with this, then write your own.
