Seismic activity is being monitored in the Dominican Republic due to the historical frequency of large earthquakes.

Seismic engineer Claudia Germoso stated that, in general, large earthquakes tend to occur at intervals of approximately 50 years, which is why specialists maintain constant monitoring of seismic activity and remain alert to the possibility of a large-magnitude event in the Dominican Republic.

Although experts agree that it is not possible to predict when an earthquake will occur, history shows that the Dominican Republic has faced some of the most destructive seismic events in the Caribbean.

The most devastating occurred on August 4, 1946, and is considered by the National Center of Seismology of the Autonomous University of Santo Domingo (CNS-UASD) to be the largest earthquake in the instrumental seismic history of the island of Hispaniola.

In that regard, Germoso reported on a seismic monitoring network for the Septentrional fault, located in the northern region of the country, which is considered one of the areas of greatest seismological threat in the Dominican Republic.

The expert explained that the project includes installing specialized sensors to characterize seismic activity in the area and collect data that will improve understanding of the fault’s behavior.

“We are installing sensors to characterize the seismicity of the area, because we understand that this is where the greatest seismic threat exists,” said the seismic engineer.

Equipment installed along the fault

The specialist indicated that they currently have several seismic instruments installed along the path of the Septentrional fault as part of the monitoring system.

He added that these stations will enable more accurate recording of seismic activity and strengthen studies of geological risk in that region.

They also monitor the southern zone.

Germoso explained that, in addition to the north of the country, specialists are also paying attention to the Enriquillo fault, located in the southern region, another geological structure with the potential to generate large-magnitude earthquakes.

He explained that the Dominican seismic code currently divides the national territory into two hazard areas: one of high seismic hazard and another of moderate seismic hazard, a classification used as a reference for the design and construction of buildings.

The engineer, who is a research professor at the Technological Institute of Santo Domingo (INTEC), reiterated the importance of continuing to strengthen scientific monitoring of the country’s main active faults to improve understanding of seismic activity and contribute to risk management.

What are seismic faults?

A seismic fault (or geological fault) is a fracture in the Earth’s crust along which blocks of rock have shifted relative to one another. Tectonic forces cause these movements and, when they suddenly release accumulated energy, generate tremors or earthquakes. 

It functions as a “rupture line” on Earth’s surface or in the subsurface, where geological movement is concentrated.

The Septentrional and Enriquillo faults are the two most important geological structures in the Dominican Republic and the island of Hispaniola. Both form part of the boundary between the North American and Caribbean plates, whose constant movement generates most of the country’s seismic activity.

The Septentrional Fault

The Septentrional fault is located in the northern region of the island and extends from Montecristi, crosses the Cibao valley, and continues to Samaná Bay, extending towards the Atlantic Ocean.

It is a lateral slip fault, which means the blocks of rock move horizontally relative to each other.

Experts consider it one of the structures with the greatest seismic threat to the Dominican Republic.

The Enriquillo fault

The Enriquillo-Plantain Garden fault is located in the southern region of Hispaniola.

Its journey begins in Jamaica, crosses southern Haiti, and continues through the southwestern Dominican Republic, bordering the Sierra de Bahoruco and extending towards the Caribbean Sea.

Like the Septentrional fault, it is a strike-slip fault in which tectonic plates move horizontally.

It is one of the most studied faults in the Caribbean because it was responsible for the Haiti earthquake of January 12, 2010, of magnitude 7.0, which left more than 300,000 dead and massive destruction in Port-au-Prince and other locations.