July 9, 1956 Tsunami: Amorgos Island, Aegean Islands, Greece
A tsunami caused by a magnitude 6.8 earthquake began at Amorgos Island, Aegean Islands, Greece on July 9, 1956 at 03:24 UTC. The water rose as high as 10 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
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
- July 9, 1956, 03:24 UTC
- Source
- Amorgos Island, Aegean Islands, Greece
- Cause
- Earthquake
- Earthquake
- Magnitude 6.8
- Maximum water height
- 10 m (32.8 ft)
- Runups recorded
- 1
- Waters
- Ocean
- How certain
- Probable tsunami
- Source location
- 36.800° N, 25.500° E
The toll
The record gives no deaths, injuries or damage for this tsunami.
What the record says
NCEI’s account, from the sources it cites.
An aftershock of the Amorgos earthquake took place. There is an assumption that it caused the local tsunami on the Island of Folegrandos located to the west of the main tsunami source behind the Islands of Ios and Sikinos, where the rise of water amounted to 10 m (it could be that this resulted precisely from the focusing of the main tsunami). (reference #2130)
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 |
|---|---|---|---|---|---|---|---|
| Folegandros | Greece | 210 | 10 | Eyewitness observation of water height |
More
Every tsunami in 1956The 1900sTsunamis of GreeceThe 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 3392.