M7.3 earthquake hits offshore Chiapas, Mexico, small tsunami waves recorded

The epicenter was located 48 km (30 miles) SW of Aquiles Serdán (population 1 135), 67 km (42 miles) SW of Huixtla (population 32 033), 72 km (44 miles) WSW of Tapachula (population 202 672), 73 km (45 miles) WNW of Brisas Barra de Suchiate (population 13 743), MExico, and 121 km (75 miles) WSW of San Marcos (population 47 063), Guatemala.

67 000 people are estimated to have felt very strong shaking, 627 000 strong, 3.3 million moderate, and 22 million light.

The Pacific Tsunami Warning Center (PTWC) said tsunami waves reaching 0.3 to 1 m (1 to 3 feet) above tide level are possible along some coasts of Guatemala and Mexico. Waves below 0.3 m (1 foot) above tide level are forecast for the coasts of Colombia, Costa Rica, Ecuador, El Salvador, Honduras, Nicaragua, Panama and Peru.

The USGS issued a Yellow alert for shaking-related fatalities and economic losses. Some casualties and damage are possible and the impact should be relatively localized. Past yellow alerts have required a local or regional level response. Estimated economic losses are less than 1% of GDP of Mexico.

Overall, the population in this region resides in structures that are a mix of vulnerable and earthquake-resistant construction. The predominant vulnerable building types are adobe block with concrete bond beam and mud wall construction.

Recent earthquakes in this area have caused secondary hazards such as landslides that might have contributed to losses.

Liquefaction triggered by this earthquake is estimated to be significant in severity and/or spatial extent. The number of people living near areas that could have produced liquefaction in this earthquake is extensive.

Little or no landsliding is expected. Little or no population is exposed to potential earthquake-induced landslides.

Update

10:10 UTC, July 18

PTWC issued its final tsunami threat message at 17:00 UTC on July 17, stating that the tsunami threat from the earthquake had passed and that there was no longer a tsunami threat.

Measured tsunami heights remained low. PTWC recorded 0.33 m (1.1 feet) at Chiapas, Mexico, at 15:59 UTC, 0.32 m (1.1 feet) at Puerto Madero, Mexico, at 15:51 UTC, and 0.01 m at DART station 43413 at 16:03 UTC.

The offshore aftershock sequence continued after the mainshock, including events in the M5 to M6 range near the Chiapas coast.

Authorities in Mexico, Guatemala, and El Salvador reported no deaths or major damage in the initial impact assessments. AP reported two injuries in southern Mexico, while Guatemala reported evacuations, minor landslides, and school closures in San Marcos, Quetzaltenango, Suchitepéquez, and Retalhuleu.

Estimated population exposure to earthquake shaking

Selected cities exposed

Regional seismicity

References:

¹ M7.3 earthquake Offshore Chiapas, Mexico – USGS – July 17, 2026

² M7.3 earthquake Offshore Chiapas, Mexico – EMSC – July 17, 2026

³ M7.3 earthquake Offshore Chiapas, Mexico – PTWC – July 17, 2026