October 23, 1950 Earthquake: San Marcos, Guatemala

Name: October 23, 1950 Earthquake: San Marcos, Guatemala
Start: 1950-10-23
Location: San Marcos, Guatemala

October 23, 1950 · M7.5

A magnitude 7.5 earthquake struck San Marcos, Guatemala on October 23, 1950 at 16:13:20 UTC, 65 km below the surface. It caused a tsunami.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date: October 23, 1950
Time: 16:13:20 UTC
Place: San Marcos, Guatemala
Magnitude: 7.5 (Mw)
Focal depth: 65 km (40 mi)
Intensity: 8 on the Modified Mercalli scale
Tsunami: Yes: the tsunami it caused
Epicenter: 14.310° N, 91.917° W
Country: Guatemala

The toll

Damage: Severe (about $5 to $25 million)
Houses destroyed: Many (101 to 1,000)
Houses damaged: Many (101 to 1,000)

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.

1950, October 23, 10:13 [local time]. There was an earthquake at Guatemala causing heavy destruction at San Marcos. Only scattered buildings escaped damage in the city, and the majority of homes were destroyed. There were injuries. The earthquake was preceded by shocks at 13:38, 14:55 and 15:04, and was followed by many recurrent shocks. In 2.2 hours after the earthquake, the tide gauge at San Jose (Guatemala) registered a wave with an amplitude of 20 cm and a period of 15 minutes. Gutenberg, Richter (1954): 23.X; 16h13m20s; 14 1/2 N, 91 1/2 W; M=7.1. (reference #415)

1950, October 23, 16:13:20 UTC, 14.5 N, 91.5 W, shallow depth, magnitude 7.1. (reference #88)

1950, October 23 16:13:20 UTC. 14.5 N, 91.5 W, magnitude 7.5 Mw P&S. (reference #9910)

1950 October 23 16:13:28.75 UTC. 14.31 N, 91.917 W, depth 65.3 km, magnitude 7.17 Mw. (reference #10476)

1950 October 23. VIII: San Marcos, La Esperanza (G); VII: Sciola (G) to Mexico border. 80% of houses seriously damaged [70 s]; buildings damaged; 12 aftershocks to 10/28 plus one on 11 /05. (reference #14066)

Other significant earthquakes nearby

Within 200 km, the deadliest first.

Significant earthquakes of 1950 The 1900s Every quake the USGS located in 1950 Recent earthquakes near here This day in weather history

Sources

Significant earthquakes 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 earthquake 6362.