Historic Tsunami

1940 Japan Tsunami

1 August 1940 · West Hokkaido Island · Japan

On 1 August 1940 at 15:08 UTC, a tsunami formed near West Hokkaido Island, Japan. It was caused by a magnitude 7.5 earthquake. Waves reached up to 5.0 m high. It was observed at 62 locations in 3 countries or territories, up to 1,031 km from its source. It killed at least 10 people and injured 24.

Date

1 August 1940

Time

15:08 UTC

Cause

Earthquake

Earthquake Magnitude

7.5

Highest Wave

5.0 m

Observation Sites

62

Furthest Reach

1,031 km

Deaths

10

Injuries

24

Homes Destroyed

20

Source Country

Japan

Triggering Earthquake

1940 Shakotan Earthquake

Countries and Territories Reached

Number of observations, highest wave and deaths in each country.

• 53Japan · 3.0 m10 deaths
• 7Russia · 5.0 m
• 2North Korea · 1.0 m

Highest Waves

• 5.0 mKamenka · Russia · 279 km
• 3.5 mTetyukhe · Russia · 294 km
• 3.0 mRishiri Island · Japan · 175 km
• 3.0 mTomamae · Japan · 172 km
• 3.0 mKutsugata, Rishiri Island · Japan · 170 km
• 3.0 mOshidomari · Japan · 179 km
• 2.8 mBeutankeushi River, Rishiri Island · Japan · 172 km
• 2.7 mBikuni · Japan · 134 km
• 2.7 mIrika · Japan · 122 km
• 2.5 mMasandomari Port, Rishiri Island · Japan · 172 km

Other Major Tsunamis in the Region

• 1993Sea of Japan, Japan · 32.0 m231 deaths
• 1983Noshiro, Japan · 14.9 m104 deaths
• 1982Hokkaido Island, Japan · 1.3 m110 deaths
• 1968Off East Coast of Honshu Island, Japan · 6.0 m52 deaths
• 1952Se. Hokkaido Island, Japan · 6.5 m33 deaths
• 1939Nw. Honshu Island, Japan · 1.2 m27 deaths

Sources: NOAA National Centers for Environmental Information, Global Historical Tsunami Database (doi:10.7289/V5PN93H7) · Natural Earth