December 4, 1918 Tsunami: Northern Chile
A tsunami caused by a magnitude 7.8 earthquake began at Northern Chile on December 4, 1918 at 11:47:48 UTC. The water rose as high as 5 meters. Its effects were recorded at 4 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
- December 4, 1918, 11:47:48 UTC
- Source
- Northern Chile
- Cause
- Earthquake
- Earthquake
- Magnitude 7.8, 33 km deep
- Maximum water height
- 5 m (16.4 ft)
- Runups recorded
- 4
- Tsunami intensity (Soloviev-Imamura)
- 2.5
- Tsunami magnitude (Iida)
- 2.3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 26.000° S, 71.000° W
The toll
- Deaths
- Few (about 1 to 50) with the earthquake or eruption that caused it
- Damage
- Limited (under about $1 million); Severe (about $5 to $25 million) with the earthquake or eruption that caused it
- Houses destroyed
- Many (101 to 1,000) 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.
December 4, 1918, 11:47.8 UTC, 26 S 71 W, magnitude 7.75 MS. Weak oscillations rapidly gaining strength began at Copiapo. The tremors lasted 3-6 minutes. After the earthquake, the sea slowly retreated from shore and the passenger quay dried up completely. Then, just as slowly, the sea flooded the beach. The usual high tide passed 11 m beyond the mean water line, but this time the water encroached 48 m, at another place, 141 m. The passenger quay was almost completely flooded. The rise of water along the vertical was 4.5-5 m above the level of regular flood tides. The ebbs and floods recurred 4-5 times. The vessels lying at anchor in the harbor were tossed about; the anchor chains were stretched to the limit.
(above from reference #415)
December 18 [should be 4], at 7:44 a.m. 1918, Copiapo. This earthquake was preceded by two foreshocks, one at 0:30 a.m. and the other about 1 minute before the mains shock. 20% of the houses in Copiapo were completely destroyed, and an equal number were seriously damaged. There was damage also in several small towns around Copiapo but not in Vallenar or Caldera. At Caldera the sea withdrew immediately after the earthquake returning four or five times to an height of up to 5 meters above mean tide. No coastal changes in level were observed. Magnitude 7.5. Moderate tsunami (Table 1). (reference #252)
December 4, 1918. Chile. Epicenter near Copiapo. Waves 15 feet above the normal tide level caused damage at Caldera. (reference #39)
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 |
|---|---|---|---|---|---|---|---|
| Caldera | Chile | 119 | 5 | 141 | Eyewitness observation of water height | ||
| San Diego, CA, CA | United States | 8,134 | 0.07 | Tide gauge (half the maximum wave height) | |||
| San Francisco, CA, CA | United States | 8,875 | Tide gauge (half the maximum wave height) | day 5, 01:00 | |||
| Honolulu, Oahu, HI, HI | United States | 10,730 | 0.07 | Tide gauge (half the maximum wave height) |
More
Every tsunami in 1918The 1900sTsunamis of ChileThe 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 1461.