Seismic activity monitoring in Iceland with fiber Bragg grating accelerometers

To monitor seismic activity using the BSI-108, a 512-pixel 8-channel interrogator with 1 pm accuracy, we developed a highly sensitive symmetrical double cantilever beam Fiber Bragg Grating (FBG) accelerometer based on designs from current literature. Our accelerometers demonstrated sensitivities of 501 pm/g, 398 pm/g, and 386 pm/g for designs employing 0.5 mm thick aluminum plates with widths of 15 mm, 20 mm, and 30 mm, respectively. The results reveal that our system is capable of detecting daily variations in ambient seismic noise attributed to anthropogenic activity. Furthermore, we demonstrated the robustness of our setup for long-term seismic monitoring in harsh outdoor environments during a summer deployment in Iceland. Despite these challenging conditions, our system successfully and accurately recorded multiple local seismic events from a nearby seismic swarm, underscoring its potential for cost-effective and reliable seismic monitoring.