December 5, 1941 Tsunami: Costa Rica-Panama
A tsunami caused by a magnitude 7.6 earthquake began at Costa Rica-Panama on December 5, 1941 at 20:46:58 UTC. The water rose as high as 0.21 meters. Its effects were recorded at 5 places. It killed 6 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
- December 5, 1941, 20:46:58 UTC
- Source
- Costa Rica-Panama
- Cause
- Earthquake
- Earthquake
- Magnitude 7.6
- Maximum water height
- 0.21 m (0.7 ft)
- Runups recorded
- 5
- Tsunami intensity (Soloviev-Imamura)
- -3
- Tsunami magnitude (Iida)
- -3.3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 8.700° N, 83.200° W
The toll
- Deaths
- 6 with the earthquake or eruption that caused it
- Injuries
- Many (about 101 to 1,000) 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
- 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 5, 1941. An earthquake at Panama and Costa Rica causing oscillations in sea level, was recorded by the tide gauge at Puntarenas (Costa Rica). The record of oscillations began at 15:45, on 90 deg West meridian time, and lasted 6 hours. The average amplitude of oscillations was 22 cm (3/4 feet), the period about 3/4 of an hour. The oscillations occurred during the flood tide. (reference #415)
The earthquake was recorded on a tide gauge at Puntarenas in Costa Rica. The disturbance began at 21 h 45 m, about one hour after the main shock, and continued for about six hours with an average range of 23 cm. (reference #8015)
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 |
|---|---|---|---|---|---|---|---|
| Puerto Jimenez | Costa Rica | 21 | Eyewitness observation of water height | ||||
| Puerto Cortes | Costa Rica | 46 | Eyewitness observation of water height | ||||
| Dominical | Costa Rica | 95 | Eyewitness observation of water height | ||||
| Parrita | Costa Rica | 153 | Eyewitness observation of water height | ||||
| Puntarenas | Costa Rica | 228 | 0.21 | Tide gauge (half the maximum wave height) | day 5, 21:30 |
More
Every tsunami in 1941The 1900sTsunamis of Costa RicaThe 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 2026-10-01. NCEI tsunami event 1748.