Movimiento del terreno en Tapachula (Chiapas), Cunduacán (Tabasco) y Tepich (Quintana Roo) en el sismo de 7.4 MW del 17 de julio de 2026

Abstract. An earthquake of magnitude 7.4 MW occurred on July 17, 2026, off the coast of Chiapas, Mexico, with an epicenter at 14.162°N, 93.287°W, and a hypocenter at a depth of 10 km. The focal mechanism corresponds to a reverse fault, consistent with the subduction of the Cocos Plate beneath the North American Plate. The USGS finite fault model estimated a seismic moment of 1.1 × 10²⁰ N·m, with a maximum slip of 2.5–3 m. Among other stations in the country, the earthquake was recorded by two Raspberry Shake stations and one station from the SSN Broadband Network. Regarding the maximum PGA and PSA values on the highest-amplitude component of the 180 horizontal axes: the closest station, R99E5, located 133 km from the epicenter and seated on firm soil, recorded a PGA of 0.15g (MMI = VI) and a PSA of 0.62g (MMI = IX) for T = 0.4 s; station RF60C, at a distance of 270 km on soft soil, presented a PGA of 0.005g (MMI = III) and a PSA of 0.019g (MMI = IV) for T = 0.5 s; and the farthest station, TEIG, 859 km from the epicenter on firm soil, recorded a PGA of 0.002g (MMI = II) and a PSA of 0.006g (MMI = III) for T = 0.2 s.