Historical tsunamis · Jul 9, 1956, 3:11 AM UTC
1956 Cyclades tsunami
Greece
The tsunami of Jul 9, 1956, 3:11 AM UTC originated near Cyclades (Greece).
Key facts
- Date
- Jul 9, 1956, 3:11 AM UTC
- Cause
- Earthquake and landslide
- Magnitude
- M7.7
- Depth
- 20 km
- Maximum documented water height
- 20.0 m
- Deaths
- 56
- Injuries
- 100
- Houses destroyed
- 529
- Damage
- severe (about US$ 5–25 million)
- Observation records
- 99
- Countries affected
- 7
It was triggered by a magnitude 7.7 earthquake at a depth of 20 km.
The highest documented water height was 20.0 m (Mouros, Greece).
99 observation sites in 7 countries are recorded.
Outside the source country, the earliest documented arrival was at Yafo (Jaffa) (Israel) after 2:48 h.
The database records 56 deaths.
Houses destroyed: 529.
Damage is estimated at severe (about US$ 5–25 million).
Map of observation sites
99Each 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) · Jul 9, 1956, 3:11 AM UTC
- 2:48 hIsrael · Yafo (Jaffa) · 0.14 m
1 places with a documented arrival time
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
| Greece | 86 | 20.0 m Mouros | 3 | — |
 Turkey | 6 | 2.10 m Yalikavak | — | — |
 Israel | 2 | 0.14 m Yafo (Jaffa) | — | 2:48 h |
 France | 2 | — | — | — |
 Egypt | 1 | — | — | — |
 Croatia | 1 | — | — | — |
 Italy | 1 | — | — | — |
Highest documented water heights
15 / 99Individual 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 |
|---|---|---|---|
| Mouros · Amorgos | 20.00 m | 18 km | Greece |
| Ambeli · Folegandros | 14.60 m | 99 km | Greece |
| Aggali · Folegandros | 12.60 m | 95 km | Greece |
| Stavros · Astypalaia | 10.00 m | 37 km | Greece |
| Agia Anna · Amorgos | 9.70 m | 18 km | Greece |
| Vai · Astypalaia | 7.50 m | 41 km | Greece |
| Stavros · Astypalaia | 7.00 m | 37 km | Greece |
| Bay 1 · Astypalaia | 4.00 m | 40 km | Greece |
| Gourna · Leros | 4.00 m | 95 km | Greece |
| Palaikastro · Crete | 4.00 m | 165 km | Greece |
| Skala · Astypalaia | 4.00 m | 38 km | Greece |
| Vrissi · Anafi | 4.00 m | 34 km | Greece |
| Mandraki · Nisyros | 3.70 m | 105 km | Greece |
| Agios Nikolaos · Folegandros | 3.10 m | 96 km | Greece |
| Eristos · Tilos | 3.10 m | 127 km | Greece |
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.