M 5.3 - 4 km S of Anse-à-Veau, Haiti

Tectonic Summary

On January 24, 2022, two prominent aftershocks of the August 14, 2021 M7.2 Nippes earthquake occurred roughly 10-15 km east of the mainshock. These January 24, 2022 M5.1 and M5.3 aftershocks occurred in western Haiti as a result of reverse faulting at shallow depths in the vicinity of the Enriquillo-Plantain Garden fault zone (EPGFZ). The aftershocks occurred roughly 110 km to the west of the Haitian capital of Port-au-Prince. Both earthquakes occurred on reverse faults moderately dipping to either the northeast or the southeast. The January 24 earthquakes are ~60 km west of the epicenter of the January 2010 M7.0 Port-au-Prince earthquake which caused over 200,000 fatalities.

Seismological and geodetic investigations of the August 2021 M7.2 Nippes earthquake indicated that it initiated on a reverse fault and propagated primarily westward and away from Port-au-Prince onto the strike-slip EPGFZ. An outcome of this earthquake was that an approximately 60-75 km seismic gap was formed between the 2010 Port-au-Prince and 2021 Nippes earthquakes. The M5.1 and M5.3 earthquakes on January 24, 2022 occurred within this seismic gap with mechanisms similar to the fault that initiated the August 2021 earthquake.

Overall, the EPGFZ accommodates about 7 mm/yr of motion, nearly half the total oblique convergence between the Caribbean and North America plates (~20 mm/yr). Haiti occupies the western part of the island of Hispaniola, one of the Greater Antilles Islands, situated between Puerto Rico and Cuba. At the location of the August 2021 earthquake, motion between the Caribbean and North America plates is partitioned between two major east-west-trending, strike-slip fault systems—the Septentrional fault system in northern Haiti and the EPGFZ in southern Haiti.