Seismo Lab Seminar

Continuous geodetic measurements near volcanic systems have revealed dynamic magmatic transport, yet capturing high spatio-temporal resolution dike intrusion dynamics remains challenging. We use low-frequency distributed acoustic sensing (LFDAS) recordings along a telecommunication fiber cable to track dike intrusions near Grindavík, Iceland. LFDAS recordings show distinct strain responses from nine intrusive events, six resulting in fissure eruptions. We image complex magma intrusions propagating on the minute time scale, forming observed lava fissures in eruptive events or remaining trapped at depth in arrested intrusions. Our results highlight the feasibility of using DAS for a dense array of strainmeters, enabling high-resolution, nearly real-time imaging of subsurface quasi-static deformations. In active volcanic regions, LFDAS recordings can offer critical insights into magmatic evolution, eruption forecasting, and volcanic hazard assessment.