Adaptive full-waveform moment-tensor inversion of microseismic data

It is very challenging to accurately invert for moment tensors of microseismic events recorded using a single-borehole geophone array. Full-waveform moment-tensor inversion uses the phase and amplitude of microseismic waveforms to invert for the moment tensor of a microseismic event. Conventional full-waveform moment-tensor inversion seeks the optimal moment-tensor solution by matching observed and synthetic waveforms, but may fail for noisy data or single-borehole geophone array with limited azimuthal coverage. We develop a novel full-waveform moment-tensor inversion method using weighted, normalized deconvolution and zero-lag cross-correlation misfit functions. The new method simultaneously estimate the event origin time and the focal mechanism in a unified inversion framework. We demonstrate that the adaptive waveform match can accurately estimate moment tensors of microseismic events at far offsets from a single-borehole geophone array.