By Kisean Joseph
The Director of the University of the West Indies (UWI) Seismic Research Centre in Trinidad has confirmed that the recent increase in earthquake activity near Antigua and Barbuda, which saw 82 recorded seismic events over just four days, is consistent with normal tectonic behavior for the region.
Last Friday alone, several quakes occurred within 24 hours. Initial reports indicate that at least five tremors were felt, with the first on November 15 registering a magnitude of 5.0.
Speaking on Observer AM, Dr Erouscilla Joseph revealed that between November 15 and 19, 2024, the area experienced significantly more seismic events than initially reported. “Two of those events were actually of a magnitude 4.8, and we had four in the range of 4.0 to 4.4,” Dr Joseph explained. The majority of events were minor tremors ranging from 0.5 to 2.9 magnitude, “below the threshold for posting to social media”.
Dr Joseph explained the phenomenon results from the region’s location in a subduction zone. “We sit in a subduction zone setting and periodically, this is slabs of rock slipping past one another,” she said. “That transition is not smooth. It often has a buildup of energy, which is released in the form of earthquakes.”
This pattern of seismic swarms is familiar to the area. “The last swarm like this was in 2022,” Dr Joseph noted. “Between the 28th of September 2022, there were over 117 events within five hours.” She emphasized that while the zone is highly active and associated with moderate to large events, there’s no need for alarm.
The expert advocated for preparedness over concern. “I would not say concern is a word I would use. I would use the word prepared,” she said. “We live in a multi-hazard environment. We have not only the geophysical events like earthquakes and volcanoes to deal with, but we also have the hydromet events.”
The seismic activity occurs along the boundary where the North American plate subducts beneath the Caribbean plate at approximately two centimeters per year. According to Dr Joseph, these periodic events are expected to continue as the plates settle into their normal movement patterns.
Dr Joseph reminds residents, that living with “mental preparedness, and then translating that into action” is key for those residing in this seismically active region.
