Historical tsunamis · Apr 30, 1919, 7:17 AM UTC
1919 Tonga Islands tsunami
Tonga
The tsunami of Apr 30, 1919, 7:17 AM UTC originated near Tonga Islands (Tonga).
Key facts
- Date
- Apr 30, 1919, 7:17 AM UTC
- Cause
- Earthquake
- Magnitude
- M8.1
- Depth
- 25 km
- Maximum documented water height
- 2.50 m
- Observation records
- 9
- Countries affected
- 5
It was triggered by a magnitude 8.1 earthquake at a depth of 25 km.
The highest documented water height was 2.50 m (Ha'apai, Tonga).
9 observation sites in 5 countries are recorded.
Outside the source country, the earliest documented arrival was at Apia, Upolu Island (Samoa) after 0:54 h.
Map of observation sites
9Each dot is a documented observation site; colour and size show the observed water height. The triangle marks the source.
Tsunami arrival times
Documented arrival times from the NOAA/NCEI database, showing the earliest recorded location per country. Coverage is incomplete: a country without an entry was not necessarily spared.
- 0:00 hEarthquake (origin) · Apr 30, 1919, 7:17 AM UTC
- 0:36 hTonga · Ha'apai · 2.50 m
- 0:54 hSamoa · Apia, Upolu Island · 0.40 m
- 6:30 hUnited States · Honolulu, Oahu, Hi · 0.10 m
- 12:43 hCanada · Tofino (Clayoquot),British Columbia · 0.08 m
7 places with a documented arrival time
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
| Tonga | 1 | 2.50 m Ha'apai | — | 0:36 h |
| USA Territory | 1 | 2.40 m Pago Pago, American Samoa | — | — |
 United States | 5 | 0.90 m Punaluu, Hawaii, Hi | — | 6:30 h |
 Samoa | 1 | 0.40 m Apia, Upolu Island | — | 0:54 h |
 Canada | 1 | 0.08 m Tofino (Clayoquot),British Columbia | — | 12:43 h |
Highest documented water heights
9 / 9Individual 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 |
|---|---|---|---|
| Ha'apai | 2.50 m | 249 km | Tonga |
| Pago Pago, American Samoa · As Classified as doubtful | 2.40 m | 491 km | USA Territory |
| Punaluu, Hawaii, Hi · Hi | 0.90 m | 4,545 km | United States |
| Hilo, Hawaii, Hi · Hi | 0.60 m | 4,624 km | United States |
| Apia, Upolu Island | 0.40 m | 507 km | Samoa |
| Honolulu, Oahu, Hi · Hi | 0.10 m | 4,669 km | United States |
| Tofino (Clayoquot),British Columbia · Bc | 0.08 m | 8,779 km | Canada |
| San Diego, Ca · Ca | 0.03 m | 8,160 km | United States |
| San Francisco, Ca · Ca | — | 8,126 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.