relMT · Development of an Advanced Software Package to Determine Relative Earthquake Moment Tensors

The seismic moment tensor is the single most important quantity characterizing the source of any subsurface shaking event, typically an earthquake. We here propose to implement, validate and advance a versatile, open-source, research-grade software package to simultaneously determine relative moment tensors of clustered seismic events with minimal data requirements. The algorithm lowers the magnitude threshold for moment tensor determination, possibly by 2 to 3 magnitudes. In this way the development of the proposed software package can increase the number of moment tensors that can be resolved by a factor of 100 to 1000. With this additional knowledge, subsurface deformation can be better understood. Applications include the important de-risking of zero-carbon energy technologies such as the stimulation of enhanced geothermal systems (EGS), or underground CO2 storage (CCS), where the proposed technology has the potential to contribute to detecting premature fault activation and cap-rock failure, thereby mitigating potential risk, increasing public acceptance and evading loss of investment. Other applications include the seismic source and stress analysis in a vast array of scientific research targets, for example when analyzing periods of tectonic or volcanic unrest, seismicity in underground mining, laboratory-scale acoustic emissions, or sources of chemical or nuclear explosions.