April 21, 1977 Tsunami: Solomon Islands
A tsunami caused by a magnitude 8.1 earthquake began at Solomon Islands on April 21, 1977 at 04:24:09 UTC. The water rose as high as 0.04 meters. Its effects were recorded at 5 places in at least 3 countries. It killed 18 people, counting the earthquake or eruption that caused it.
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
- April 21, 1977, 04:24:09 UTC
- Source
- Solomon Islands
- Cause
- Earthquake
- Earthquake
- Magnitude 8.1, 33 km deep
- Maximum water height
- 0.04 m (0.1 ft)
- Runups recorded
- 5
- Tsunami intensity (Soloviev-Imamura)
- -1.5
- Tsunami magnitude (Iida)
- -3.3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 9.965° S, 160.731° E
The toll
- Deaths
- 18 with the earthquake or eruption that caused it
- Injuries
- 1 with the earthquake or eruption that caused it
- Damage
- Severe (about $5 to $25 million) with the earthquake or eruption that caused it
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What the record says
NCEI’s account, from the sources it cites.
On April 21, 1977, at 04:21 UTC, the [fourth] strong earthquake on the Solomon Islands occurred at a magnitude of 7.5, five hours after the first shock in roughly the same region as the two previous shocks. Eighteen people were killed by landslides. Fairly severe destruction was caused in Guadalcanal. A weak tsunami caused by this earthquake was recorded on the Solomon Islands, northeast of Australia and in the western part of Samoa. (reference #417)
Slight tsunami at Apia and Suva. Felt (VII) at Honiara. (reference #1053)
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 |
|---|---|---|---|---|---|---|---|
| Cairns | Australia | 1,791 | 0.03 | Tide gauge (half the maximum wave height) | day 21, 10:49 | ||
| Townsville, Queensland | Australia | 1,814 | 0.04 | Tide gauge (half the maximum wave height) | day 21, 10:45 | ||
| Brisbane | Australia | 2,083 | Tide gauge (half the maximum wave height) | day 21, 12:50 | |||
| Suva | Fiji | 2,112 | Eyewitness observation of water height | ||||
| Apia, Upolu Island | Samoa | 3,025 | 0.03 | Tide gauge (half the maximum wave height) |
More
Every tsunami in 1977The 1900sTsunamis of Solomon IslandsThe 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 2090.