September 21, 1908 Tsunami: Hawaii, United States
A tsunami caused by a magnitude 6.8 earthquake began at Hawaii, United States on September 21, 1908 at 06:31 UTC. The water rose as high as 1.2 meters. Its effects were recorded at 2 places.
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
- September 21, 1908, 06:31 UTC
- Source
- Hawaii, United States
- Cause
- Earthquake
- Earthquake
- Magnitude 6.8, 33 km deep
- Maximum water height
- 1.2 m (3.9 ft)
- Runups recorded
- 2
- Tsunami intensity (Soloviev-Imamura)
- 0
- Tsunami magnitude (Iida)
- -0.5
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 19.000° N, 155.000° 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.
September 21, 1908, 06:42 UTC, 19.5 N, 155.4 W, magnitude 6.8. A magnitude 6.8 earthquake occurring on September 20 a few minutes after 8:00 P.M. local time with a source near the southeast coast of Hawaii Island caused the water in the harbors and rivers of Hilo to rise about 1.2 m. Some shore residents were frightened and came to town for the night. There is some confusion regarding the time and location of this event. Pararas-Carayannis and Calebaugh (1977) give the time as 6:15 UTC by incorrectly converting a time of 8:15 P.M. local time to UTC by adding 10 hours instead of 10:30. Cox (1986) gives the local time as 2012, possibly the average of 2008 and 20:15 given by other sources and gives the Universal time as 06:22. Similarly, the locations vary by half of a degree in both latitude and longitude. (reference #236)
There was an earthquake with source south-east of Hawaii Island. The shore in the Puna district may have sunk 10 cm. The water in the harbor and in the rivers of Hilo rose 0.3-0.8 m (Reference #415).
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 |
|---|---|---|---|---|---|---|---|
| Hilo, Hawaii, HI, HI | United States | 81 | 1.2 | Tide gauge (half the maximum wave height) | |||
| Puna District, Hawaii, HI | United States | Eyewitness observation of water height |
More
Every tsunami in 1908The 1900sTsunamis of United StatesThe 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 1371.