Historical tsunamis · Oct 20, 1986, 6:46 AM UTC
1986 Kermadec Islands tsunami
New Zealand
The tsunami of Oct 20, 1986, 6:46 AM UTC originated near Kermadec Islands (New Zealand).
Key facts
- Date
- Oct 20, 1986, 6:46 AM UTC
- Cause
- Earthquake
- Magnitude
- M7.8
- Depth
- 29 km
- Maximum documented water height
- 0.22 m
- Observation records
- 8
- Countries affected
- 3
It was triggered by a magnitude 7.8 earthquake at a depth of 29 km.
The highest documented water height was 0.22 m.
8 observation sites in 3 countries are recorded.
Outside the source country, the earliest documented arrival was at Pago Pago, American Samoa (USA Territory) after 2:14 h.
Map of observation sites
8Each 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) · Oct 20, 1986, 6:46 AM UTC
- 2:14 hUSA Territory · Pago Pago, American Samoa · 0.05 m
- 4:29 hFrench Polynesia · Papeete, Tahiti · 0.07 m
- 8:32 hUnited States · Honolulu, Oahu, Hi · 0.07 m
7 places with a documented arrival time
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
 United States | 5 | 0.11 m Hilo, Hawaii, Hi | — | 8:32 h |
 French Polynesia | 2 | 0.10 m Rapa | — | 4:29 h |
| USA Territory | 1 | 0.05 m Pago Pago, American Samoa | — | 2:14 h |
Highest documented water heights
8 / 8Individual 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 |
|---|---|---|---|
| Hilo, Hawaii, Hi · Hi | 0.11 m | 5,770 km | United States |
| Rapa | 0.10 m | 3,147 km | French Polynesia |
| Kahului, Maui, Hi · Hi | 0.08 m | 5,830 km | United States |
| Honolulu, Oahu, Hi · Hi | 0.07 m | 5,819 km | United States |
| Honuapo, Hawaii, Hi · Hi | 0.07 m | 5,683 km | United States |
| Papeete, Tahiti · Society Islands | 0.07 m | 2,981 km | French Polynesia |
| Pago Pago, American Samoa · As | 0.05 m | 1,641 km | USA Territory |
| Kailua-Kona, Hawaii, Hi · Hi | 0.04 m | 5,720 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.