September 30, 1636 Tsunami: Ionian Sea, Greece

Name: September 30, 1636 Tsunami: Ionian Sea, Greece
Start: 1636-09-30
Location: Ionian Sea, Greece

September 30, 1636 · 520 deaths · Very doubtful tsunami

A tsunami caused by a magnitude 7.2 earthquake began at Ionian Sea, Greece on September 30, 1636 at 18:30 UTC. Its effects were recorded at 1 place. It killed 520 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

Tsunami warnings in force

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: September 30, 1636, 18:30 UTC
Source: Ionian Sea, Greece
Cause: Earthquake
Earthquake: Magnitude 7.2
Runups recorded: 1
Tsunami intensity (Soloviev-Imamura): 3
Waters: Ocean
How certain: Very doubtful tsunami
Source location: 38.100° N, 20.300° E

The toll

Deaths: 520 with the earthquake or eruption that caused it
Damage: Severe (about $5 to $25 million) with the earthquake or eruption that caused it
Houses destroyed: Many (101 to 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.

1636, Sept 30. Midnight. Island of Kefallonia. Tsunami. Tsunami intensity 3, validity 1. (reference #2130)

1636, Oct 12, 18 30 UTC. Ionian Sea, 38o06'N, 20o18'E, earthquake magnitude 7.2, intensity IX, tsunami intensity 2, reliability 2. Sea disturbance in Kefalonia. (reference #2427)

1636, Oct 12, 18:30. 38o06' N, 20o18' E, earthquake magnitude 7.2, intensity IX, tsunami intensity 2, reliability 2. Sea disturbance in Kefalonia. (reference #2591)

1636, Sept 30. Kefalonia. An earthquake caused extensive damage in the southern part of Kefalonia and Zante. It occurred at about 6pm on Friday 30 September (O.S.) and lasted for about 30 seconds. The earthquake destroyed or ruined all the houses and taller buildings in Kefalonia, not only in Kastro (Argostoli) and its suburbs, but also in the rest of the island, killing about 520 people. The districts of Argostoli, Livatho, Ikosima, Elios, Valta, Koroni, Irakli, and Pirgi, in the southern part of the island, were totally destroyed. The ground motion was very strong, making it impossible to walk. Maximum damage occurred in the southern part of the island... The effects on Zakynthos were as bad, if not worse. Houses and monasteries are reported to have collapsed all over the island, resulting in the deaths of several hundred people... The shock was felt at sea, but contrary to what modern writers report, the earthquake was not associated with a seismic sea wave. (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
Kefallonia Island, Ionian Islands	Greece	18			Eyewitness observation of water height

Every tsunami in 1636 The 1600s Tsunamis of Greece The earthquake This day in weather history Alerts 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 3130.