Historical tsunamis · May 26, 1975, 9:11 AM UTC
1975 Azores Gibraltar Fracture Zone tsunami
Atlantic Ocean
The tsunami of May 26, 1975, 9:11 AM UTC originated near Azores Gibraltar Fracture Zone (Atlantic Ocean).
Key facts
- Date
- May 26, 1975, 9:11 AM UTC
- Cause
- Earthquake
- Magnitude
- M7.8
- Depth
- 33 km
- Maximum documented water height
- 0.50 m
- Damage
- limited (under US$ 1 million)
- Observation records
- 14
- Countries affected
- 5
It was triggered by a magnitude 7.8 earthquake at a depth of 33 km.
The highest documented water height was 0.50 m (Ponta Delgada, Azores (Portugal)).
14 observation sites in 5 countries are recorded.
Outside the source country, the earliest documented arrival was at Santa Cruz, Tenerife, Canary Is (Spain) after 1:28 h.
Damage is estimated at limited (under US$ 1 million).
Map of observation sites
14Each 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) · May 26, 1975, 9:11 AM UTC
- 1:28 hSpain · Santa Cruz, Tenerife, Canary Is · 0.04 m
- 1:34 hAzores (Portugal) · Horta, Ilha de Fayal, Azores · 0.35 m
- 6:00 hUnited Kingdom · Newlyn, Cornwall, England · 0.03 m
6 places with a documented arrival time
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
| Azores (Portugal) | 3 | 0.50 m Ponta Delgada | — | 1:34 h |
 Portugal | 1 | 0.30 m Lagos | — | — |
 Spain | 7 | 0.14 m Cadiz | — | 1:28 h |
 United Kingdom | 1 | 0.03 m Newlyn, Cornwall, England | — | 6:00 h |
 Morocco | 2 | — | — | — |
Highest documented water heights
14 / 14Individual 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 |
|---|---|---|---|
| Ponta Delgada | 0.50 m | 748 km | Azores (Portugal) |
| Horta, Ilha de Fayal, Azores | 0.35 m | 1,021 km | Azores (Portugal) |
| Lagos | 0.30 m | 808 km | Portugal |
| Cadiz | 0.14 m | 1,015 km | Spain |
| Tarifa | 0.07 m | 1,079 km | Spain |
| Santa Cruz, Tenerife, Canary Is | 0.04 m | 840 km | Spain |
| Newlyn, Cornwall, England | 0.03 m | 1,846 km | United Kingdom |
| Algeciras | 0.02 m | 1,094 km | Spain |
| Arrecife, Lanzarote Island | 0.02 m | 863 km | Spain |
| Ceuta | 0.02 m | 1,106 km | Spain |
| La Coruna | 0.02 m | 1,136 km | Spain |
| Casablanca | — | 948 km | Morocco |
| Mogador (Essaouira) | — | 875 km | Morocco |
| Sao Miguel Harbor, Azores | — | 748 km | Azores (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.