World Tsunami Awareness Day: Theme, Major causes, Natural Warning Signs and India's Tsunami Early Warning System

Why in news?

World Tsunami Awareness Day 2026 will be observed on 5 November 2026 across the world.

Key facts

Particulars	Details
Day	World Tsunami Awareness Day
Date	5 November
First observed	2016
Established by	United Nations General Assembly
Resolution	A/RES/70/203
Theme 2026	Be Tsunami Ready: Resilience Starts With You
Main objective	Promote tsunami awareness and preparedness
Lead UN body	United Nations Office for Disaster Risk Reduction (UNDRR)
Global scientific coordination	UNESCO-IOC

What is a Tsunami?

A series of extremely long ocean waves generated by the sudden displacement of a large volume of seawater.
The word tsunami originates from Japanese: Tsu (Harbour) and Nami (Wave).
A tsunami may travel across entire ocean basins and cause severe destruction when it reaches shallow coastal waters.

Major causes of tsunamis

Cause	Explanation
Undersea earthquakes	Sudden movement of tectonic plates displaces the ocean floor and pushes large amounts of water.
Volcanic eruptions	Underwater or coastal volcanic eruptions can displace seawater.
Submarine landslides	Large underwater masses of soil and rocks suddenly move, generating waves.
Meteorite impacts	A large object striking the ocean can displace enormous volumes of water.

How does a Tsunami occur?

Tectonic movement: An earthquake occurs beneath the ocean due to the movement of tectonic plates.
Seafloor displacement: The ocean floor suddenly rises or sinks, displacing the water column above it.
Wave generation: The displaced water generates a series of long waves that spread in different directions.
Oceanic propagation: The waves travel across the ocean at high speeds, often with relatively small wave heights in deep water.
Coastal amplification: As the waves enter shallow coastal waters, they slow down and their height can increase significantly.
Coastal inundation: The waves move inland, flooding coastal settlements and damaging infrastructure.

Tsunami vs Normal Ocean Waves

Basis	Normal Ocean Waves	Tsunami
Main cause	Wind	Earthquakes, landslides, volcanic activity
Wavelength	Relatively short	Extremely long
Speed	Generally lower	Can exceed 800 km/h in deep oceans
Energy	Mostly concentrated near the surface	Involves movement of the entire water column
Impact	Usually limited to surface activity	Can cause extensive coastal flooding
Number of waves	Usually individual or continuous wind-driven waves	A series of waves

Why is World Tsunami Awareness Day Observed on 5 November?

On 5 November 1854, a Japanese villager named Hamaguchi Goryo noticed signs of an approaching tsunami.
He set fire to his harvested rice sheaves to alert villagers and guide them towards higher ground.
This action helped save the lives of many people.
The incident became an important example of community-based disaster preparedness and the importance of recognising natural warning signs.
In December 2015, the United Nations General Assembly adopted Resolution A/RES/70/203, designating 5 November as World Tsunami Awareness Day. The first observance took place in 2016.

What are the Natural Warning Signs of a Tsunami?

Warning sign	What it indicates
Strong or prolonged earthquake	Possible undersea tectonic activity
Sudden rise or withdrawal of seawater	Possible tsunami approaching the coast
Loud roaring sound from the ocean	Possible approaching tsunami waves
Unusual behaviour of the sea	Potential coastal hazard

Why are Tsunamis a Major Global Concern?

Area	Impact
Human life	Large-scale deaths, injuries and displacement
Infrastructure	Destruction of houses, roads, bridges, ports and communication networks
Economy	Damage to fisheries, tourism, agriculture and coastal industries
Environment	Coastal erosion, saltwater intrusion and destruction of marine ecosystems
Agriculture	Salinization of agricultural land and contamination of freshwater sources
Public health	Risk of waterborne diseases, sanitation problems and psychological trauma

Major Tsunami Disasters in History

Year	Location	Significance
1960	Chile	The Great Chilean Earthquake generated a trans-Pacific tsunami.
2004	Indian Ocean	One of the deadliest tsunamis in recorded history, affecting several countries.
2011	Japan	The Tohoku earthquake triggered a devastating tsunami and the Fukushima nuclear accident.

India's Vulnerability to Tsunamis

India has a coastline of approximately 7,516.6 km, including its mainland and island territories.
Its geographical location exposes it to tsunami risks originating from seismic activities in the Indian Ocean region.

Region	Tsunami vulnerability
Andaman and Nicobar Islands	Located close to the seismically active Sunda subduction zone.
Tamil Nadu	Exposed to tsunami waves originating from the eastern Indian Ocean.
Andhra Pradesh	Vulnerable due to its long Bay of Bengal coastline.
Odisha	Coastal settlements are exposed to multiple ocean-related hazards.
Kerala	Vulnerable to tsunami waves originating in the Indian Ocean.
Pondicherry	Its coastal location creates exposure to tsunami-related hazards.

India's Tsunami Early Warning System

Following the devastating Indian Ocean Tsunami of 2004, India established a dedicated tsunami early warning system to improve monitoring, forecasting and disaster preparedness. The system became fully operational in October 2007.
Indian Tsunami Early Warning Centre (ITEWC)
Established at the Indian National Centre for Ocean Information Services (INCOIS), Hyderabad.
Operates under the Ministry of Earth Sciences (MoES).
Functions as India's national authority for issuing tsunami advisories.
Operates 24 hours a day, seven days a week.
Monitors seismic activity and sea-level changes to identify potential tsunami threats.

How does India's Tsunami Early Warning System work?

Component	Function
Seismic stations	Detect earthquakes and determine their magnitude and location.
Bottom Pressure Recorders (BPRs)	Detect changes in water pressure at the ocean floor.
Tsunami buoys	Transmit ocean measurements to monitoring centres.
Tide gauges	Measure changes in sea level along coastlines.
Numerical models	Estimate tsunami propagation and potential coastal impact.
Warning centre	Analyses data and issues tsunami advisories to relevant authorities.

Major Global Initiatives for Tsunami Preparedness

Initiative	Organisation	Objective
World Tsunami Awareness Day	UN General Assembly	Promote global tsunami awareness and preparedness.
Sendai Framework for Disaster Risk Reduction (2015–2030)	United Nations	Reduce disaster risks and losses through prevention, preparedness and resilience.
Tsunami Ready Programme	UNESCO-IOC	Strengthen community-level tsunami preparedness.
Early Warnings for All (EW4All)	United Nations	Ensure that everyone is protected by early warning systems.
Indian Ocean Tsunami Warning and Mitigation System (IOTWMS)	UNESCO-IOC	Coordinate tsunami warning and mitigation across the Indian Ocean.

Prelims MCQ

Q. Consider the following statements regarding tsunamis:

Tsunamis are primarily generated by underwater earthquakes.
The Indian Tsunami Early Warning Centre is located in Hyderabad.
UNESCO-IOC coordinates regional tsunami warning systems.
Tsunamis are caused exclusively by earthquakes.

Which of the statements given above are correct?

(a) 1 and 2 only

(b) 1, 2 and 3 only

(c) 2 and 4 only

(d) All four

Mains Practice Question

Q. Discuss the role of early warning systems and disaster resilience in reducing tsunami-related risks, with special reference to India.

FAQs

When is World Tsunami Awareness Day observed?

5 November every year.

What is the theme of World Tsunami Awareness Day 2026?

Be Tsunami Ready: Resilience Starts With You.

Which organisation coordinates global tsunami warning systems?

UNESCO's Intergovernmental Oceanographic Commission (IOC).

Where is India's Tsunami Early Warning Centre located?

INCOIS, Hyderabad.

Which disaster led India to establish its tsunami early warning system?

The Indian Ocean Tsunami of 26 December 2004.

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