Why this matters now
Tsunamis (especially after 2004), coastal hazards and the early-warning system are tested in GS-3 — India has a 7,500+ km coastline at risk.
How tsunamis form
A tsunami is a series of huge ocean waves caused by the sudden displacement of water — usually by undersea earthquakes (along subduction zones), and sometimes landslides or volcanic eruptions. Waves travel fast in deep water and rise dramatically near the shore. The 2004 Indian Ocean tsunami (Sumatra earthquake) devastated coasts and killed over two lakh people.
Other coastal hazards
Coastal disasters also include cyclonic storm surges, coastal flooding, erosion, saltwater intrusion and sea-level rise (worsened by climate change). India’s east coast is especially cyclone-prone; mangroves and reefs provide natural protection.
Early warning and management
After 2004, India set up the Indian Tsunami Early Warning Centre at INCOIS (Hyderabad) — a 24×7 system using seismic and ocean (buoy/tide-gauge) data to issue alerts. Management combines early warning, coastal zone regulation, mangrove restoration, resilient infrastructure, evacuation drills and community awareness.
UPSC angle
Know tsunami causation (undersea earthquakes/subduction), the 2004 Indian Ocean tsunami, the INCOIS tsunami early-warning centre, coastal hazards (surge/erosion/SLR) and mangrove protection.
Frequently asked questions
What causes a tsunami?
The sudden displacement of large volumes of water, usually by an undersea earthquake along a subduction zone.
What was the 2004 Indian Ocean tsunami?
A catastrophic tsunami triggered by a Sumatra earthquake that killed over two lakh people across the region.
Who issues tsunami warnings in India?
The Indian Tsunami Early Warning Centre at INCOIS, Hyderabad.
What protects coasts naturally?
Mangroves and coral reefs buffer storm surges and erosion.