October 6, 1987 Tsunami: Tonga Islands
A tsunami caused by a magnitude 7.3 earthquake began at Tonga Islands on October 6, 1987 at 04:19:06 UTC. The water rose as high as 0.25 meters. Its effects were recorded at 2 places in at least 2 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 6, 1987, 04:19:06 UTC
- Source
- Tonga Islands
- Cause
- Earthquake
- Earthquake
- Magnitude 7.3, 16 km deep
- Maximum water height
- 0.25 m (0.8 ft)
- Runups recorded
- 2
- Tsunami magnitude (Iida)
- -3.3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 17.940° S, 172.225° 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 7.3 Ms (NEIC) earthquake at 4:19 UT was felt at Nuku'alofa and American Samoa producing a tsunami at Pago Pago, American 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 | 437 | 0.12 | Tide gauge (half the maximum wave height) | day 6, 05:10 | ||
| Apia, Upolu Island | Samoa | 458 | 0.02 | Tide gauge (half the maximum wave height) |
More
Every tsunami in 1987The 1900sTsunamis of TongaThe 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 2174.