July 18, 1923 Tsunami: Butuan, Sulu Sea, Philippines
A tsunami caused by a magnitude 5.5 earthquake began at Butuan, Sulu Sea, Philippines on July 18, 1923 at 02:24:19 UTC. 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
The tsunami
- Date
- July 18, 1923, 02:24:19 UTC
- Source
- Butuan, Sulu Sea, Philippines
- Cause
- Earthquake
- Earthquake
- Magnitude 5.5
- Runups recorded
- 1
- Tsunami intensity (Soloviev-Imamura)
- 1
- Tsunami magnitude (Iida)
- 0.5
- Waters
- Ocean
- How certain
- Questionable tsunami
- Source location
- 9.300° N, 125.000° 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.
Reference #40:
1923, July 18. Waves reported from Mambajao (09'15' N., 124'43'E.) and Camiguin Island (09'11'N., 124'42'E.). The disturbance of the sea lasting about an hour, (Repetti 1931).
Reference #414:
1923, July 18, 10:42 [local time], 9.5 N, 127 E, magnitude 5.5 MS. There was an earthquake of intensity 3 degrees at Butuan and on Camiguin Island. It was reported, that several minutes later, during the ebb tide, enormous waves coming from the Surigao Strait were observed at Mambajao. The coast was inundated. The water rose higher than during the greatest flood tides. The rough sea lasted about an hour. No similar reports of rough sea were received from any other places. Repetti (1931): 18.VII; 2h42m19s; 9.3 N, 125 E. Listed as questionable tsunami
Reference #10958:
1923, July 18. Berninghausen (1969) cited a work by Repetti (1931) about the observance of waves associated with this earthquake that were reported in Mambajao and Camiguin island that lasted for about an hour. The account stated that several minutes after an earthquake, big waves coming from Surigao Strait were observed at Mambajao and inundated the coast. This is not found in SEASEE (1985). Tsunami probability is ranked as “positive”
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 |
|---|---|---|---|---|---|---|---|
| Mambajao, Camiguin Island | Philippines | 32 | Eyewitness observation of water height |
More
Every tsunami in 1923The 1900sTsunamis of PhilippinesThe 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 1522.