Historical tsunamis · Nov 25, 1941, 6:03 PM UTC
1941 Azores Gibraltar Fracture Zone tsunami
Atlantic Ocean
The tsunami of Nov 25, 1941, 6:03 PM UTC originated near Azores Gibraltar Fracture Zone (Atlantic Ocean).
Key facts
- Date
- Nov 25, 1941, 6:03 PM UTC
- Cause
- Earthquake
- Magnitude
- M7.8
- Depth
- 10 km
- Maximum documented water height
- 0.23 m
- Observation records
- 13
- Countries affected
- 5
It was triggered by a magnitude 7.8 earthquake at a depth of 10 km.
The highest documented water height was 0.23 m (Mogador (Essaouira), Morocco).
13 observation sites in 5 countries are recorded.
Outside the source country, the earliest documented arrival was at Casablanca (Morocco) after 2:00 h.
Map of observation sites
13Each dot is a documented observation site; colour and size show the observed water height. The triangle marks the source.
Tsunami arrival times
Documented arrival times from the NOAA/NCEI database, showing the earliest recorded location per country. Coverage is incomplete: a country without an entry was not necessarily spared.
- 0:00 hEarthquake (origin) · Nov 25, 1941, 6:03 PM UTC
- 2:00 hMorocco · Casablanca · 0.13 m
- 3:57 hUnited Kingdom · Newlyn, Cornwall, England · 0.10 m
3 places with a documented arrival time
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
 Morocco | 2 | 0.23 m Mogador (Essaouira) | — | 2:00 h |
 United Kingdom | 1 | 0.10 m Newlyn, Cornwall, England | — | 3:57 h |
| Azores (Portugal) | 3 | 0.06 m Ponta Delgada | — | — |
 Portugal | 6 | — | — | — |
 France | 1 | — | — | — |
Highest documented water heights
13 / 13Individual documented observations for this event. Heights come from different measurement types and sources; not every location has a measured height.
| Location / station | Observed height | Distance from source | Country |
|---|---|---|---|
| Mogador (Essaouira) | 0.23 m | 1,061 km | Morocco |
| Casablanca | 0.13 m | 1,109 km | Morocco |
| Newlyn, Cornwall, England | 0.10 m | 1,780 km | United Kingdom |
| Ponta Delgada | 0.06 m | 595 km | Azores (Portugal) |
| Angra do Heroismo, Terceira | — | 742 km | Azores (Portugal) |
| Cascais | — | 853 km | Portugal |
| Horta, Ilha de Fayal, Azores | — | 860 km | Azores (Portugal) |
| Lagos | — | 914 km | Portugal |
| Le Havre Classified as doubtful | — | 2,043 km | France |
| Leixoes | — | 984 km | Portugal |
| Pontinha, Madeira Island | — | 550 km | Portugal |
| Tejo (Tagus) | — | 890 km | Portugal |
| Vila de Franca de Xira | — | 892 km | Portugal |
More tsunamis
Source: NOAA National Centers for Environmental Information (NCEI), Global Historical Tsunami Database. Confirmed events only. Deaths and damage are database estimates; older records are incomplete. Water heights come from different types of observation.