I was a teenager on the Caribbean island of St Vincent when a volcano called La Soufrière erupted unexpectedly on 13 April 1979. A rumbling as loud as jet engines woke my family. The volcano was some 30 kilometres away on the other side of the island, but the plume of ash in the sky was spectacular. My father and I drove towards it to evacuate my grandmother; there were people on the streets with donkeys, carrying bundles, and ash was falling on us like rain.

That dramatic event made a lasting impression. I went on to study geology, and for more than a decade I led the University of the West Indies Seismic Research Centre at St Augustine, Trinidad, where I still work. My team tracks 17 volcanoes across the Lesser Antilles islands in the Caribbean, using GPS to monitor seismic activity and ground deformation. We also do public outreach, educating people about the hazards and what to do in case of an eruption.

In December 2020, a lava dome formed on La Soufrière and grew quickly. This was during the COVID-19 pandemic; we couldn’t hold community meetings, so we drove around with a loudspeaker to alert people at risk. In April 2021, the volcano erupted explosively. It did a lot more damage than in 1979, but less than it caused in its last really big eruption, in 1902. People were scared: the ash darkened the sky. But thanks to an evacuation order 24 hours earlier, 16,000 people were moved to safety.

These days, I go to St Vincent every two or three months. In this photo I’m checking a rain gauge that we installed after the 2021 eruption. We’re researching how much rain it takes to trigger mudslides of loose ash.

Several volcanoes on Dominica have shown signs of activity in the past 10 or 20 years. The island of Montserrat has been rumbling since 1995; the volcanoes on Martinique and Guadeloupe are also fairly active. But, aside from a submarine volcano near Grenada, La Soufrière remains the most active in the Lesser Antilles archipelago.