Abstract

Recent advances in low-cost seismic node technology offer new opportunities for high-resolution monitoring and characterisation of geothermal systems, which are critical for the low-carbon energy transition. I will present results from a dense deployment of 450 seismic nodes at a geothermal site in Cornwall, United Kingdom during well stimulation activities. I’ll also discuss the benefits and challenges of working with the nodal system, and discuss the methods and results used in the processing of the data. Using automated workflows, we detected and relocated 241 induced earthquakes with waveform-migration and double-difference methods, enabling imaging of fault structures. Source parameters, including moment magnitudes, stress drops, fault radii, and focal mechanisms, were used to infer fault stress conditions and fluid–fault interactions. To complement the earthquake-based analysis, three-component beamforming of ambient seismic noise was recently applied to estimate Rayleigh-wave velocities and anisotropy, providing an independent constraint on fracture orientations and permeability structure at depth. Our findings highlight the potential and flexibility of nodal array data for passive seismic monitoring of induced seismicity.