January 20, 1917 Tsunami: Bali Sea, Indonesia
A tsunami caused by a magnitude 6.6 earthquake began at Bali Sea, Indonesia on January 20, 1917 at 23:11:34 UTC. The water rose as high as 2 meters. Its effects were recorded at 2 places. It killed 1,500 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
Travel times
How long the first wave took to reach each part of the ocean, one line for each hour up to 24, estimated from the source and the depth of the sea.
The travel times are computed in your browser, which needs JavaScript.
- 1 to 4 hours
- 5 to 6 hours
- 7 to 14 hours
- 15 hours and more
Computed in your browser the way NOAA’s own travel time maps are: the wave travels at the square root of gravity times the depth, over NOAA’s ETOPO1 depths averaged to a 10 arc-minute grid. Checked against NOAA NCEI’s maps for 21 tsunamis over the first 24 hours, these lines fall within 10 minutes of NCEI’s at half the points compared and within 52 minutes at 9 in 10. They give when the first wave could arrive, not how high it is; bays, harbors and island chains finer than the grid can see it later. Not for use in a warning: see tsunami.gov.
The tsunami
- Date
- January 20, 1917, 23:11:34 UTC
- Source
- Bali Sea, Indonesia
- Cause
- Earthquake
- Earthquake
- Magnitude 6.6, 33 km deep
- Maximum water height
- 2 m (6.6 ft)
- Runups recorded
- 2
- Tsunami magnitude (Iida)
- 1
- Waters
- Ocean
- How certain
- Probable tsunami
- Source location
- 7.000° S, 116.000° E
The toll
- Deaths
- 1,500 with the earthquake or eruption that caused it
- Damage
- Moderate (about $1 to $5 million) with the earthquake or eruption that caused it
- Houses destroyed
- Some (about 51 to 100) 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.
January 21, 1917 6:50 [local time], [January 20, 23:11:34 UTC; 7 S., 116 E., magnitude 6.6.]. There was an earthquake with source, according to the Wiechert seismograph at Djakarta (Batavia), southeast of Bali Island. There were numerous landslides and avalanches, which buried houses and people (about 80% of the total number of victims in the earthquake were due to avalanches). A small tidal wave was observed on the southeastern shore of Bali Island from Klunkung to Baenoa. The wave did no damage. (reference #414)
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 |
|---|---|---|---|---|---|---|---|
| Klunkung, Bali Island | Indonesia | 186 | Eyewitness observation of water height | ||||
| Benoa, Bali Island | Indonesia | 215 | Eyewitness observation of water height |
More
Every tsunami in 1917The 1900sTsunamis of IndonesiaThe 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 1439.