August 23, 1817 Tsunami: Corinthos-Patras Gulf, Greece
A tsunami caused by a magnitude 6.6 earthquake began at Corinthos-Patras Gulf, Greece on August 23, 1817 at 08:00 UTC. The water rose as high as 12 meters. Its effects were recorded at 4 places. It killed 128 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
- August 23, 1817, 08:00 UTC
- Source
- Corinthos-Patras Gulf, Greece
- Cause
- Earthquake
- Earthquake
- Magnitude 6.6
- Maximum water height
- 12 m (39.4 ft)
- Runups recorded
- 4
- Tsunami intensity (Soloviev-Imamura)
- 3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 38.300° N, 22.100° E
The toll
- Deaths
- 18; 128 with the earthquake or eruption that caused it
- Damage
- Limited (under about $1 million); Severe (about $5 to $25 million) with the earthquake or eruption that caused it
- Houses destroyed
- Very many (over 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.
Ionian Sea, Gulf of Corinth. On August 23 1817 (possibly 1818) a destructive earthquake occurred, preceded by the strong August 13 shock. Aiyion became a heap of ruins. An underwater landslide occurred. The sea water, which suddenly became warm, flooded the coastal part of the town Aiyion and Cape Aliki. The earthquake caused significant damage to buildings in Patras and, on the whole, to the north-west of Peloponnesus (in Elis), but it was only slightly felt in Corinth. Many strong aftershocks occurred during 8 following days. (reference #2130)
About one and a half minutes after the earthquake the sea flooded the low land below Vostiza, all the way inland to the mouth of the river of Vostiza (Melanites). In the roadstead of Vostiza the sea rose 20 pichis (20 cubits: 12 m, sic.), carrying away a number of shops and drowning 18 people, most of them women and children who at the time had been fetching water from the springs in the low-lying part of the town (Xinopoulos 1912, 10). Two sailing ships in the port were cast onto land and destroyed. Other, smaller, sailing boats at anchor in the roadstead escaped damage, but all fishing boats near the shore were flung onto land and more or less shattered (Leake 1830, iii. 402). To the east of the town all level ground between the mouth of the Selinus river and Vostiza was flooded temporarily by the sea, and the flow of the river was arrested for some time. The sea retreated back to its normal level, leaving no trace of some magazines that had stood on the shore, and the sand which had covered the beach was all carried away, changing the shore land (Wyse 1865, 260). A cape in the vicinity of the site of Kalogria was engulfed in the sea, and totally disappeared. In the bay of Trizonia, on the northern coast of the Gulf of Corinth, the sea rose in the same manner as at Vostiza and advanced 200 paces into the plain; it is not known whether it caused any damage. The seismic sea wave was also reported from Galaxidi (Christomanos 1870a; 1870b). (reference #9116)
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 |
|---|---|---|---|---|---|---|---|
| Aiyion (Aigio) | Greece | 6 | 12 | 75 | Eyewitness observation of water height | 18 | |
| Trizonia | Greece | 8 | 150 | Eyewitness observation of water height | |||
| Galaxidi | Greece | 26 | Eyewitness observation of water height | ||||
| Cape Aliki | Greece | 84 | Eyewitness observation of water height |
More
Every tsunami in 1817The 1800sTsunamis 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 619.