April 3, 1787 Tsunami: San Marcos, Mexico
A tsunami caused by a magnitude 7.3 earthquake began at San Marcos, Mexico on April 3, 1787 at 15:30 UTC. The water rose as high as 4 meters. Its effects were recorded at 3 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
- April 3, 1787, 15:30 UTC
- Source
- San Marcos, Mexico
- Cause
- Earthquake
- Earthquake
- Magnitude 7.3
- Maximum water height
- 4 m (13.1 ft)
- Runups recorded
- 3
- Tsunami intensity (Soloviev-Imamura)
- 1
- Tsunami magnitude (Iida)
- 2
- Waters
- Ocean
- How certain
- Questionable tsunami
- Source location
- 15.500° N, 97.000° W
The toll
- Damage
- Moderate (about $1 to $5 million) 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.
1747, April 3, 9:30 - 10:00 [local time]. Apparently, this was the strongest aftershocks of the March 28, 1787 earthquake. In some places on the coast, situated 18 km (4 leagues) from Tehuantepec, an unusual movement of the water and a menacing roar were observed simultaneously with the earthquake. Previously unknown fishes and enormous shellfish were tossed onshore. The same occurred on the coast at Pochutla and Juquila. (reference #415)
A wave height of 4 m was estimated. (reference #369)
The 3 April 1787 earthquake produced greater damage [compared to the 28 March 1787 event] in Tehuantepec, and although it is not completely clear in the report published by the Gazette of Mexico, “…it produced an alteration in the sea near Tehuantepec, accompanied by bellows and which throws fish and shells onto the beach”; Orozco and Berra added that this phenomenon also occurred on the coast between Pochutla and Juquila. (reference #12967)
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 |
|---|---|---|---|---|---|---|---|
| Juquila | Mexico | 57 | 4 | Eyewitness observation of water height | |||
| Pochutla (Puerto Angel) | Mexico | 58 | 4 | Eyewitness observation of water height | |||
| Southeast Oaxaca Coast | Mexico | 228 | 4 | Eyewitness observation of water height |
More
Every tsunami in 1787The 1700sTsunamis 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 545.