July 30, 1909 Tsunami: S. Mexico
A tsunami caused by a magnitude 7.4 earthquake began at S. Mexico on July 30, 1909 at 10:51:54 UTC. The water rose as high as 9 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
The tsunami
- Date
- July 30, 1909, 10:51:54 UTC
- Source
- S. Mexico
- Cause
- Earthquake
- Earthquake
- Magnitude 7.4
- Maximum water height
- 9 m (29.5 ft)
- Runups recorded
- 1
- Tsunami magnitude (Iida)
- 3.2
- Waters
- Ocean
- How certain
- Questionable tsunami
- Source location
- 16.800° N, 99.800° W
The toll
- 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.
On July 30 (incorrectly 31), 1909 at 4:16 [local time, 10:51.9 UTC], there was an earthquake with source near Acapulco, where many homes were destroyed. The destruction occurred on a large area which included San Marcos and Chilpancingo. The earthquake was felt in a zone about 2500 km by 780 km. At Acapulco, the sea receded from the shore; the flood tide reached 9 m [apparently along the horizontal]. (reference #415)
30-foot tidal wave. (reference #132)
Reference #13234 cites 50 meter sea withdrawal at Acapulco. Same reference also has accounts from 1909 on 31 July and 02 August that were possible aftershocks in same epicentral region causing the sea to recede.
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 |
|---|---|---|---|---|---|---|---|
| Acapulco | Mexico | 13 | 9 | Eyewitness observation of water height |
More
Every tsunami in 1909The 1900sTsunamis of MexicoThe 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 1382.