[4] The earthquake occurred in the Pacific Ocean, more than 120 km (75 mi) south of El Salvador's Usulután department, on 26 August at 22:37 CST.

[1] A 2013 study published in Earth and Planetary Science Letters determined that the earthquake ruptured a west–northwest striking, northeast dipping fault plane by applying seismic inversion on 83 broadband P-wave records.

The study concluded that the El Salvador event displayed tsunami earthquake characteristic similar to the shock that affected Nicaragua in 1992.

[7] Servicio Nacional de Estudios Territoriales evaluated the shaking in San Salvador to be II (Weak) on the Modified Mercalli intensity scale.

[9] Eight minutes after the earthquake, at 22:45, the Pacific Tsunami Warning Center (PTWC) issued an advisory along the Central American coasts.

Eleven minutes later, the PTWC raised their advisory to a tsunami warning after receiving strong evidence of its rupture characteristic.

[6] The tsunami impacted a sparsely populated part of the Salvadorian coast, while in Nicaragua, three coastal settlements experienced 0.5 m (1 ft 8 in) of flooding.

[9] Along the coast of the San Juan del Gozo Peninsula, Usulután, close to the epicenter, the tsunami had greater coastal effects.

At a section of beach near La Maroma village, which hosted a sea turtle hatchery, the tsunami destroyed the walls of a ramada and tilted its wooden supports.

Another eyewitness in Corral de Mulas reported two waves with the second being the largest; they topped a fence post located 1 m (3 ft 3 in) above the dune crest and several meters inland.