| Abstract |
The Soufrière Hills Volcano on Montserrat, in the Lesser Antilles, was active from 1995 to 2010, causing devastation in the southern part of the island. Since then the island has been rebuilding with a focus on decarbonization and geothermal energy. Over a decade ago, three exploration wells were drilled, revealing geothermal potential exceeding the island’s energy needs. In 2024, the University of Oxford, funded by the Oxford Martin School and in collaboration with the Montserrat Volcano Observatory (MVO), launched a new geophysical campaign to expand previous geophysical surveys and deepen geothermal exploration. The MVO’s broadband seismic network has been augmented to 16 instruments, and 120 Sercel WiNG seismic nodes were deployed in key locations. These nodes significantly enhance the resolution of both seismic activity and passive imaging techniques such as tomography. The project uses volcano-tectonic earthquakes and ambient noise imaging to map three-dimensional compressional and shear wave velocity structures. Finite frequency sensitivity kernels are applied in place of traditional ray paths to better reflect realistic data sensitivity. Results show notable seismic velocity anomalies associated with volcanic and geothermal features. High P- and S-wave velocities are observed beneath Soufrière Hills and the older Central Hills volcanic centres. A pronounced low-velocity anomaly appears west of the island, aligned with the site of previously drilled high-temperature geothermal wells. This feature extends laterally, and is detectable down to approximately 3.5 km depth, offering valuable insight into the island’s geothermal potential. |