World Tsunami Awareness Day (November 5): History & Safety Tips

In 1854, when a huge earthquake struck Japan, a village leader named Hamaguchi Goryō saw the sea pull back and knew a tsunami was coming. He set fire to his own rice sheaves on a hill so the villagers would run uphill to help — and they escaped the wave. That story, known as Inamura-no-hi (“the fire of rice sheaves”), is why World Tsunami Awareness Day is held on November 5.

At a glance
Date	November 5 every year
Established	UN General Assembly, December 2015
Proposed by	Japan, with many co-sponsoring countries
Coordinated by	UN Office for Disaster Risk Reduction (UNDRR)
Core message	Early warning and early action save lives
Hashtags	#TsunamiDay #WorldTsunamiDay

What Is a Tsunami?

A tsunami is a series of powerful ocean waves usually caused by an undersea earthquake, but also by landslides or volcanic eruptions. In the deep ocean the waves travel as fast as a jet plane yet may be less than a metre high. Near the coast they slow down and grow into walls of water that can flood far inland. The word comes from Japanese: tsu (harbour) + nami (wave).

Deadliest Tsunamis in Modern History

Year	Event	Impact
1755	Lisbon earthquake and tsunami	Tens of thousands killed in Portugal, Spain and Morocco
1883	Krakatoa eruption, Indonesia	More than 36,000 killed
2004	Indian Ocean tsunami	About 227,000 killed in 14 countries
2011	Great East Japan Earthquake	About 18,000 killed; Fukushima nuclear accident
2018	Sulawesi and Sunda Strait, Indonesia	Thousands killed

Natural Warning Signs

• Strong or long earthquake shaking near the coast.
• The sea suddenly drawing back, exposing the seabed.
• A loud roar from the ocean, like a train or jet.
• Unusual rise or fall of the sea level.

If you are on the coast and feel a strong earthquake or see the sea retreat — don’t wait for an official warning. Go high or go inland immediately.

Tsunami Safety: What to Do

1. Move to high ground or inland at once, on foot if possible.
2. Follow marked evacuation routes.
3. If you cannot leave, go to the upper floors of a strong concrete building.
4. Stay away until officials say it is safe — the first wave is often not the biggest.
5. Prepare a family emergency plan and grab bag.

How the World Prepares

After 2004, countries created the Indian Ocean Tsunami Warning and Mitigation System, joining the Pacific system set up decades earlier. UNESCO’s Intergovernmental Oceanographic Commission supports warning centres, and the Tsunami Ready programme helps coastal communities prepare evacuation maps, drills and signs.

👉 Related: Environment and nature days

👉 Plan ahead: All November observances

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