October 20, 1986 Tsunami: Kermadec Islands, New Zealand
A tsunami caused by a magnitude 7.8 earthquake began at Kermadec Islands, New Zealand on October 20, 1986 at 06:46:09 UTC. The water rose as high as 0.22 meters. Its effects were recorded at 8 places in at least 3 countries.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
The tsunami
- Date
- October 20, 1986, 06:46:09 UTC
- Source
- Kermadec Islands, New Zealand
- Cause
- Earthquake
- Earthquake
- Magnitude 7.8, 29 km deep
- Maximum water height
- 0.22 m (0.7 ft)
- Runups recorded
- 8
- Tsunami magnitude (Iida)
- -2.18
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 28.117° S, 176.367° W
The toll
The record gives no deaths, injuries or damage for this tsunami.
What the record says
NCEI’s account, from the sources it cites.
A magnitude 8.1 Ms earthquake at 6:46 UT in the Kermadec Islands near New Zealand created a tsunami recorded in Hawaii, Tahiti and Samoa.
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| Pago Pago, American Samoa, AS | US Territories | 1,641 | 0.05 | Tide gauge (half the maximum wave height) | day 20, 09:00 | ||
| Papeete, Tahiti | French Polynesia | 2,981 | 0.07 | Tide gauge (half the maximum wave height) | day 20, 11:15 | ||
| Rapa | French Polynesia | 3,147 | 0.1 | ||||
| Honuapo, Hawaii, HI, HI | United States | 5,683 | 0.07 | Tide gauge (half the maximum wave height) | day 20, 15:35 | ||
| Kailua-Kona, Hawaii, HI, HI | United States | 5,720 | 0.04 | Tide gauge (half the maximum wave height) | day 20, 15:32 | ||
| Hilo, Hawaii, HI, HI | United States | 5,770 | 0.11 | Tide gauge (half the maximum wave height) | day 20, 15:32 | ||
| Honolulu, Oahu, HI, HI | United States | 5,819 | 0.07 | Tide gauge (half the maximum wave height) | day 20, 15:18 | ||
| Kahului, Maui, HI, HI | United States | 5,830 | 0.08 | Tide gauge (half the maximum wave height) | day 20, 15:20 |
More
Every tsunami in 1986The 1900sTsunamis of New ZealandThe earthquakeThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 2166.