Antigua and Barbuda was among the closest land masses to a moderate earthquake that struck the northeastern Caribbean in the early hours of Thursday morning, according to data released by the University of the West Indies Seismic Research Centre (UWI SRC).

The quake, measured at magnitude 3.9, occurred at 3:19 AM local time (7:19 UTC) and was centred approximately 78 kilometres southeast of Saint John’s — placing the capital city as the second-nearest major population centre to the epicentre.

The epicentre was located at latitude 17.69°N, longitude 62.25°W, at a depth of 42 kilometres. Basseterre, Saint Kitts and Nevis, was the nearest city at 69 km to the northeast, while Brades, Montserrat, lay approximately 99 km to the north.

This is a preliminary report based on automatically generated data from the UWI Seismic Research Centre. Details may be updated as analysts review the event.