Raspberry Shake Instruments Provide Initial Ground-Motion Assessment of the Induced Seismicity at the United Downs Deep Geothermal Power Project in Cornwall, United Kingdom

Abstract Raspberry Shake (RS) seismographs offer the potential for affordable and citizen-led seismic monitoring in areas with few publicly available seismometers, especially previously quiescent regions experiencing induced seismicity. However, their scientific regulatory remains largely untested. We examine ground motions recorded by 11 RS one broadband station within 15 km of United Downs Deep Geothermal Power (UDDGP) project Cornwall, Kingdom, to evaluate network’s suitability provide an initial ground-motion assessment region. To date, British Geological Survey (BGS) has reported 232 events originating at UDDGP since flow testing began summer 2020, two exceeding local magnitude (ML) 1.5. Although accelerometers are too noisy UDDGP’s microseismic events, vertical geophones useful. Peak velocity observations consistent relevant models, whereas peak acceleration (PGA) values greater than predicted. Regional trends PGA levels likely caused path effects. Finally, estimates ML similar those BGS. For sparse national networks, stations can enable a preliminary evaluation motions.