Press release from LMI CARIBACT* (URGéo, Faculty of Sciences of the State University of Haiti and Géoazur, Côte d’Azur University and Observatory, CNRS, IRD, France) on the earthquake of August 14, 2021. Translated by Frederic Lucas-Conwell
*The CARIBACT International Joint Laboratory, funded by the Research Institute for Development (IRD), is a partnership between the URGéo laboratory of the Faculty of Sciences of the State University of Haiti and the French Geoazur Laboratory (Côte d’Azur University and Observatory, CNRS, IRD). Contacts: dmboisson@yahoo.com, eric.calais@ens.fr.
August 14, 2021 , 6 p.m. Haiti.
A magnitude 7 earthquake occurred on August 14, 2021 in southern Haiti at 8:30 a.m. local time. It reminds us of the devastating event of January 12, 2010, of similar magnitude, which caused tens of thousands of victims in the Léogâne – Port-au-Prince region, and whose economic cost was exorbitant. At the time of writing, it seems that the level of damage from this most recent earthquake, although significant, is lower than in 2010. However, we must wait for a complete analysis before being able to conclude precisely.
This earthquake, felt throughout the country as well as in the Dominican Republic and Cuba, was particularly well recorded by the citizen seismological network “ayiti-earthquakes” developed within the framework of the S2RHAI project thanks to funding from the “Natural Risks” program of the French CNRS and the IRD, with contributions from the Faculty of Sciences of the ‘Haitian State University, the Bureau of Mines and Energy of Haiti, the Côte d’Azur University and Observatory (France), the Euro-Mediterranean Seismological Center, the École Normale Supérieure (France) and the Interreg project Caribbean PREST.
Currently available data indicate that the epicenter of the main shock is in the province of Nippes, in the south of the country, about 10 kilometers east of Baradères and 20 kilometers southwest of Anse à Veau. It is possible that this earthquake mobilized the fault of the Southern Peninsula (also called “Enriquillo – Plantain Garden Fault”); field studies have just been launched to determine this. They will also make it possible to understand the evolution of the sequence of aftershocks in progress, which will continue for several more weeks.
Preliminary information indicates that it is a shallow earthquake, probably located in the first 10 kilometers of the earth’s crust with a mechanism that combines north-south shortening and strike-slip motion, similar to what happened in 2010. The energy released by this earthquake is slightly greater than that of the 2010 earthquake. The main shock continues to be followed by aftershocks, some of which have reached sufficient magnitude to cause further damage. This seismic sequence can be followed in real time on https://ayiti.unice.fr/ayiti-seismes/ thanks to the citizen seismological stations ayiti-earthquakes.
The earthquake of August 14, 2021 has its epicenter in a particularly seismic region of the southern peninsula of Haiti. The region of Anse à Veau was indeed affected on April 8, 1860 by a strong earthquake, then on October 27, 1952 by an earthquake, which caused significant material damage and at least six deaths. The latter was followed by an important aftershock on January 25, 1953, of magnitude 5.7. This same region was the site of a small seismic crisis in September and October 2015.
