Historical tsunamis · Aug 6, 1788
1788 Shumagin Islands, Ak tsunami
United States
The tsunami of Aug 6, 1788 originated near Shumagin Islands, Ak (United States).
Key facts
- Date
- Aug 6, 1788
- Cause
- Earthquake
- Magnitude
- M8.0
- Maximum documented water height
- 88.0 m
- Deaths
- many (about 101–1,000)
- Observation records
- 3
- Countries affected
- 1
It was triggered by a magnitude 8.0 earthquake.
The highest documented water height was 88.0 m (Unga Island, Ak, United States).
3 observation sites in 1 countries are recorded.
The database records many (about 101–1,000) deaths.
Map of observation sites
3Each dot is a documented observation site; colour and size show the observed water height. The triangle marks the source.
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
| United States | 3 | 88.0 m Unga Island, Ak | — | — |
Highest documented water heights
3 / 3Individual documented observations for this event. Heights come from different measurement types and sources; not every location has a measured height.
| Location / station | Observed height | Distance from source | Country |
|---|---|---|---|
| Unga Island, Ak · Ak | 88.00 m | 35 km | United States |
| Sanak Island, Ak · Ak | 30.00 m | 127 km | United States |
| Pavlof Village Alaska Peninsula, Ak · Ak | 5.00 m | 62 km | United States |
More tsunamis
Source: NOAA National Centers for Environmental Information (NCEI), Global Historical Tsunami Database. Confirmed events only. Deaths and damage are database estimates; older records are incomplete. Water heights come from different types of observation.