According to Claude Prépetit, between August 4 and 5, nearly nine seismic tremors were recorded on Haitian soil. Of these nine tremors, one occurred in the Nippes region and the other eight were concentrated between Pétion-Ville, Croix-des-Bouquets, and Fonds Parisien. The engineer-geologist noted that these were surface tremors at very shallow depths—between 7 and 10 km.

The highest recorded magnitude of these tremors was 4.1 on the Richter scale, Prépetit said, referring to the one that occurred on August 4 at 11:00 p.m. Another tremor of magnitude 3.4 was recorded the next day at 3:23 a.m. In the afternoon of Tuesday, August 5, another tremor of magnitude 3.2 was observed at 5:18 p.m. Aside from these three, the remaining tremors were of lower magnitude, Prépetit explained.