On August 29, 1741 CE, a destructive tsunami struck the western coast of Hokkaido Island, Japan. According to the NOAA/NCEI Global Historical Tsunami Database, the event is assigned a definitive validity rating of 4, indicating a definite tsunami occurrence. The disaster was associated with an earthquake measuring magnitude 6.9 and resulted in a recorded maximum water height of 90.0 meters, alongside a total of 2,000 fatalities.
Event Overview and Measurements
Historical records from the NOAA/NCEI database capture several core metrics defining the scope and severity of the August 29, 1741 CE event:
- Event Date: August 29, 1741 CE
- Location: Western Hokkaido Island, Japan (Latitude 41.5, Longitude 139.37)
- Earthquake Magnitude: 6.9
- Maximum Water Height: 90.0 meters
- Fatalities: 2,000 deaths
- Database Validity: 4 (Definite tsunami)
Understanding the Context
Tsunamis are ocean waves typically generated by large-scale disturbances of the sea floor, such as earthquakes, landslides, or volcanic activity. In this instance, the event was explicitly associated with an earthquake of magnitude 6.9. The recorded maximum water height of 90.0 meters represents the highest measured runup or wave height documented for the event at its most severely impacted points, rather than a uniform height across the entire region. The resulting impact led to significant loss of life, with 2,000 recorded deaths.
Frequently asked questions
When did the western Hokkaido Island tsunami occur?
The tsunami occurred on August 29, 1741 CE.
What was the magnitude of the earthquake associated with the 1741 Hokkaido tsunami?
The event was associated with an earthquake of magnitude 6.9.
What was the maximum water height recorded for the tsunami?
The recorded maximum water height reached 90.0 meters.
How many fatalities were recorded from the event?
The historical database records 2,000 deaths resulting from the tsunami.
Sources and further context
Official datasets support the event-specific facts.