23 BC Tsunami: Alexandria, Egypt
A tsunami of unknown cause began at Alexandria, Egypt in 23 BC. Its effects were recorded at 2 places.
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
The tsunami
- Date
- 23 BC
- Source
- Alexandria, Egypt
- Cause
- Unknown
- Earthquake
- The earthquake
- Runups recorded
- 2
- Tsunami intensity (Soloviev-Imamura)
- 3
- Waters
- Ocean
- How certain
- Probable tsunami
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.
23 +3 B.C. Egyptian coasts between Alexandria and Pelusium. A seismic sea-wave probably connected with the 26 B.C. earthquake in Cyprus. (reference #15)
23 +3 B.C., Egyptian coasts between Alexandria and Pelusium, tsunami intensity III. Earthquake intensity IX, 38 1/4 N, 22 1/4E. (reference #20)
23 B.C. Paphos (Cyprus), Earthquake. Sea-wave at Pelusium (Egypt), tsunami event validity 3. (reference #2815)
20 B.C., Lower Egypt. Strabo says that when he was residing in Alexandria (up to 20 BC), 'the sea about Pelusium and Mt. Casius rose and flooded the country and made an island of the mountain, so that the road by Mt. Casius into Phoenice became navigable'. He does not mention the occurrence of an earthquake and he probably refers to the effects of a sea-wave generated by submarine slumping off the north coast of Egypt, perhaps triggered by an earthquake. Contrary to the assertion of Ben-Menahem, Nur and Vered (1976), no earthquake in that period is mentioned by contemporary historians. Large-scale flooding of the coast is considered by Strabo to be a rare event that has been observed, however, both in 20 and 139 B.C. and
in earlier times, on the Egyptian and Syrian coasts. He
does not associate these events with earthquakes, as
implied by Cledat (1920, p. lIS; 1923, p. 6S). See also,
Sieberg (I932b, p. 187) and Ben-Menahem (1979). (reference #3845)
20 B.C. Pelusium. Strabo says that when he was residing in Alexandria (until c. 20 BC), '...the sea about Pelusium and Mt Casius rose and flooded the country and made an island of the mountain, so that the road by Mt Casius into Phoenice became navigable...' Elsewhere he refers to this event as being due to the sudden change of the level of the marshy ground around Pelusium and, contrary to the assertion of modern catalguers, he does not mention the occurrence of an earthquake before or during this phenomenon. (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 |
|---|---|---|---|---|---|---|---|
| Alexandria | Egypt | Eyewitness observation of water height | |||||
| Pelusium | Egypt | Eyewitness observation of water height |
More
Every tsunami in 23 BC99 to 1 BCTsunamis of EgyptThe earthquakeAlerts 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 19.