August 20, 1920 Tsunami: Central Chile
A tsunami caused by a magnitude 7 earthquake began at Central Chile on August 20, 1920 at 16:15:38 UTC. The water rose as high as 1.4 meters. Its effects were recorded at 1 place.
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
- August 20, 1920, 16:15:38 UTC
- Source
- Central Chile
- Cause
- Earthquake
- Earthquake
- Magnitude 7, 15 km deep
- Maximum water height
- 1.4 m (4.6 ft)
- Runups recorded
- 1
- Tsunami intensity (Soloviev-Imamura)
- 1
- Tsunami magnitude (Iida)
- 0.5
- Waters
- Ocean
- How certain
- Probable tsunami
- Source location
- 38.000° S, 73.500° W
The toll
- 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
- Houses damaged
- 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.
August 20, 1920, 11:30 [local time], 38 S, 73.5 W, magnitude 7. There was an earthquake on the coast of Chile which was felt from the mouth of the Mataquito River to Reloncavi Fiord. In the harbor at Talcahuano, the movements of the water, which followed the earthquake, tossed about the vessels riding at anchor. (reference #415)
August 20, 1920, 16;15 UTC, 38 S, 73.5 W, depth 15 km, magnitude 7.0 or 5.5, runup height 1.4 m. (reference #552)
Aug. 20, 1920, Chile. Submarine shock felt from the mouth of the Rio Mataquito 36 deg 00 min S. to the fiord Relonquavi 41 deg 03 min S. Ships violently thrown about by movements of the water at Talcahuano. (reference #39)
August 20, 1920, Southern Chile. Talcahuano, ships at anchor violently thrown about by consecutive movements of waves. As likely to have been a seiche or even a sea quake. (reference #79)
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 |
|---|---|---|---|---|---|---|---|
| Talcahuano | Chile | 150 | 1.4 | Eyewitness observation of water height |
More
Every tsunami in 1920The 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 1485.