Tsunami in India: the warning signs, how INCOIS warns you, and what coastal families and tourists should do

Most of us in India think of a tsunami as something that happens to other countries. Then 26 December comes round, and the memory of 2004 returns. India does have a tsunami risk, a national warning centre in Hyderabad, and two coastal villages in Odisha that UNESCO’s Intergovernmental Oceanographic Commission recognised as Tsunami Ready, according to INCOIS. This page explains where the danger comes from, what the warning signs are, how an official alert reaches you, and what to do. It follows the Indian National Centre for Ocean Information Services (INCOIS), the Gujarat and Andaman and Nicobar disaster management departments, and our own suggestions where marked. Checked 10 November 2026.

In short

• A strong earthquake near the coast, a long rumbling of the ground, or the sea suddenly pulling back or rising fast is a warning. Do not wait for a siren or an SMS. Move inland and to higher ground at once.
• Never go to the beach to watch. The state guidance says if you can see the wave, you are too close to escape it.
• Stay on high ground until the local authorities say it is safe to return.
• INCOIS in Hyderabad runs the Indian Tsunami Early Warning Centre, operating round the clock since October 2007, and sends advisories to the authorities by email, fax, SMS and its website.
• Save yourself, not your belongings. The Andaman and Nicobar guidance says so in so many words.

Where India’s tsunami risk comes from

INCOIS names two known source zones for tsunamis that can reach India: the Andaman, Nicobar and Sumatra island arc in the east, and the Makran subduction zone in the Arabian Sea in the west. Both are subduction zones, where one plate dives under another, and large earthquakes there can lift or drop the sea floor and push the water above it. INCOIS also says tsunamis can come from underwater landslides and volcanic eruptions. Major tsunamis are produced by large, shallow earthquakes in marine and coastal regions, usually above magnitude 7. It adds that tsunamis are infrequent in the Indian Ocean (about six events were reported in the twentieth century), but they can come at any time and could be very destructive.

INCOIS lists the older events that affected the Indian coast. A magnitude 7.8 earthquake beneath Car Nicobar on 31 December 1881 sent a tsunami along the whole east coast, including the Andamans and Nicobars. The eruption of Krakatoa in Indonesia on 27 August 1883 raised a tsunami that INCOIS says reached about 2 metres at Chennai. A magnitude 8.1 earthquake in the Andamans on 26 June 1941 affected the east coast. A magnitude 8.1 earthquake in the Makran zone on 27 November 1945 affected the west coast; INCOIS gives about 2 metres for the waves at Mumbai, where boats were taken from their moorings and there were casualties. Then came 26 December 2004, which INCOIS calls one of the strongest ever and the deadliest tsunami of all time by an order of magnitude, and which led the government to build the early warning system.

How the waves behave

INCOIS explains that in the open ocean a tsunami is only a small hump, barely noticeable, travelling at 500 to 1,000 kilometres an hour. As it reaches shallow water it slows to tens of kilometres an hour, but its height grows, and near the coast it may be several metres or more. On shore it can look like a rapidly rising or falling tide, a series of breaking waves, or a bore. This is why a clear sea in front of you tells you nothing about the water that is coming.

The natural warning signs

The Gujarat Institute of Disaster Management guidance says people living along the coast should treat an earthquake or a sizable ground rumbling as a warning signal, and that a noticeable rapid rise or fall in coastal waters is also a sign that a tsunami is approaching. The Andaman and Nicobar guidance says that if the water recedes noticeably from the shoreline, you should become cautious and move away immediately.

• Strong or long shaking in a coastal area.
• The sea pulling back far from the shore, or rising rapidly.
• Any official warning on radio, television, SMS or loudspeaker.

Our suggestion: do not wait to see which comes first. One sign is enough to go.

How an official warning reaches you

INCOIS says the Indian Tsunami Early Warning Centre in Hyderabad was set up after the 2004 tsunami and has been operational since October 2007. It uses a real-time network of seismic stations, deep-sea bottom pressure recorders, tide gauges and a round-the-clock warning centre. INCOIS says the centre can detect tsunamigenic earthquakes in the Indian Ocean and the global oceans within about 10 minutes, and one INCOIS page puts it at less than 12 minutes for events above magnitude 6. It disseminates advisories to the concerned authorities by email, fax, SMS, the Global Telecommunication System and its website; it is then for the authorities to pass the warning on to the public, as we understand it. INCOIS also issues storm surge advisories. Whether your own area has sirens, loudspeakers or an SMS list is a local matter, so ask your district disaster management office.

INCOIS says plainly that a tsunami cannot be prevented, but its impact can be reduced by community and emergency preparedness, timely warnings, effective response and public education.

Tsunami Ready: what a prepared village looks like

The Odisha State Disaster Management Authority ran a pilot of the UNESCO Intergovernmental Oceanographic Commission’s Tsunami Ready programme in six coastal villages. Two of them, Venkatraipur in Ganjam district and Noliasahi in Jagatsinghpur district, were recognised as Tsunami Ready by the commission, making India the first country in the Indian Ocean region, and Odisha the first state, to get the recognition, according to INCOIS. A Tsunami Ready community must meet 11 indicators, including a risk reduction plan, mapped hazard and inundation zones, tsunami information on public display, easy evacuation maps, outreach and education, at least three outreach activities a year and an annual community exercise. Newer news reports speak of many more villages being recognised, but we did not open an official page confirming that. A good question to ask your own panchayat, society or hotel is whether it has an evacuation map and when it last held a drill. Our guide to early warning systems in India, in the related list, shows how alerts reach people.

What to do: before, during and after

Before. The Gujarat guidance says to make sure all family members know how to respond, pick an elevated inland location and more than one evacuation route, since roads may be blocked after an earthquake. Teach family members how and when to turn off gas, electricity and water, teach children the plan in advance, and keep an emergency kit with a torch and spare batteries, a battery radio, a first aid kit, emergency food and water and essential medicines. Our suggestion for tourists and hotel guests: ask at reception where the high ground or the upper floors for evacuation are, and keep your shoes, phone and room key where you can grab them.

During.

1. If you hear a warning or notice a sign, move at once to higher ground and stay there until local authorities say it is safe to return.
2. Go in an orderly, calm and safe manner to the evacuation site.
3. Listen to a radio or television for the latest information.
4. Stay away from the beach. Never go down to watch a tsunami come in.
5. Stay away from debris in the water, which can hurt people and boats.
6. Save yourself, not your possessions.

After. The Gujarat list says to stay tuned to a battery-operated radio, help injured or trapped people, stay out of damaged buildings and return home only when authorities say it is safe. Enter your home with caution and use a torch. Check for electrical shorts and live wires and do not use appliances or lights until an electrician has checked the system. Open windows and doors to help dry the building. Check food supplies and test drinking water, and throw out fresh food that touched flood water.

What not to do

• Do not go to the shore to see or film the sea retreat or the wave.
• Do not wait for an official alert if you feel strong shaking on the coast.
• Do not go back for belongings.
• Do not return because the sea looks calm; wait for the authorities.
• Do not drive towards the sea or park on a coastal road in a warning.

Not every earthquake brings a tsunami warning. Our case study of the Shizuoka earthquake in Japan notes that no tsunami warning was issued. That is why the local rule above matters: strong shaking on the coast means move.

For earthquakes and cyclones, which are the other coastal dangers, see the related list, and the city guides for Chennai, Visakhapatnam, Kochi, Cuddalore and Kakinada.

What we could not confirm

NDMA’s tsunami page on its website holds videos and posters rather than text, and we could not open the NDMA tsunami guidelines (2010) in full; the steps come from INCOIS pages and the Gujarat and Andaman and Nicobar disaster departments. INCOIS pages give slightly different detection times (about 10 minutes and less than 12 minutes) and counts of sea sensors, so we give only what is consistent. We did not find a current national list of tsunami-ready villages or of coastal towns that have sirens. The 1945 and 1883 wave heights are INCOIS’s historical estimates. This page is general information, not an emergency plan for your own area; follow your district authorities.