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Science & Nature • Natural Disaster

2011 Tōhoku earthquake and tsunami

The 2011 Tōhoku earthquake and tsunami was a major natural disaster that struck northeastern Japan on 11 March 2011.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 27, 2026|2 min read| Fact-checked

The 2011 Tōhoku earthquake and tsunami was a major natural disaster that struck northeastern Japan on 11 March 2011. A powerful offshore earthquake generated tsunami waves that caused widespread coastal devastation and led to the Fukushima Daiichi nuclear accident.

Background

The disaster began with a major offshore megathrust earthquake along the Japan Trench near the Tōhoku region. It was one of the strongest earthquakes ever recorded in Japan and produced a large tsunami within minutes.

Tsunami impact

The tsunami struck coastal areas of northeastern Honshu with extreme force, in some places reaching run-up heights near 40 metres. It flooded large areas inland, destroyed settlements, and caused extensive loss of life and property.

Fukushima nuclear accident

Flooding from the tsunami disabled power and cooling systems at the Fukushima Daiichi Nuclear Power Plant. This led to a severe nuclear accident and large-scale evacuations.

Casualties and damage

The disaster caused about 20,000 deaths or missing persons according to official Japanese reporting, along with thousands of injuries. It also produced enormous economic and infrastructure losses.

Key facts

  • The earthquake struck offshore of northeastern Japan and generated a destructive tsunami.
  • Tsunami waves reached heights of nearly 40 metres in some areas.
  • The tsunami inundated coastal communities and caused severe damage to homes, roads, railways, and infrastructure.
  • The disaster triggered the Fukushima Daiichi nuclear accident after floodwaters disabled key safety systems.
  • Official Japanese government figures later reported 19,759 deaths, 6,242 injured, and 2,553 missing.
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Canadian context

The disaster prompted tsunami monitoring, emergency planning, and public-awareness efforts in Pacific Canada, especially along British Columbia’s coast.

Frequently asked questions

What was the 2011 Tōhoku earthquake and tsunami?
It was a major earthquake off northeastern Japan on 11 March 2011 that generated a destructive tsunami and a major nuclear accident.
How strong was the earthquake?
It is commonly reported as magnitude Mw 9.0 or 9.1.
How high were the tsunami waves?
Some tsunami waves and run-up measurements were near 40 metres in parts of Japan.
How many people died?
Official Japanese reporting later listed 19,759 deaths, 6,242 injured, and 2,553 missing.
Did the disaster affect the Fukushima nuclear plant?
Yes. Tsunami flooding disabled safety systems at Fukushima Daiichi and contributed to a major nuclear accident.

References

  1. Wikipediahttps://en.wikipedia.org/wiki/2011_T%C5%8Dhoku_earthquake_and_tsunami
    Supports: Tsunami heights, travel speed, inland reach, and 2021 official casualty figures.
  2. Encyclopaedia Britannicahttps://www.britannica.com/event/Japan-earthquake-and-tsunami-of-2011
    Supports: Date, location, disaster description, and overall death toll estimates.
  3. NOAA National Centers for Environmental Informationhttps://www.ncei.noaa.gov/news/day-2011-japan-earthquake-and-tsunami
    Supports: Magnitude, arrival time of tsunami, and major impacts including reactor disablement.
  4. National Geographic Educationhttps://education.nationalgeographic.org/resource/tohoku-earthquake-and-tsunami/
    Supports: Tsunami mechanism, wave heights, displacement, and Fukushima-related impacts.
  5. World Visionhttps://www.worldvision.org/disaster-relief-news-stories/2011-japan-earthquake-and-tsunami-facts
    Supports: Magnitude, flooded area, evacuees, and estimated economic loss.
  6. Japan Reconstruction Agencyhttps://www.reconstruction.go.jp/english/topics/GEJE/
    Supports: Official Japanese summary of deaths, injuries, and missing persons.
  7. NOAA National Geophysical Data Centerhttps://www.ngdc.noaa.gov/hazard/11mar2011.html
    Supports: Earthquake magnitude, location, depth, and Pacific-wide tsunami observation.