Simultaneous microearthquake location and moment‐tensor estimation using time‐reversal imagingAuthors:
We use time‐reversal imaging for microearthquake location and investigate the possibility of a simultaneous qualitative moment‐tensor estimation. We cross‐correlate the data with the synthetic strain Green's tensor and stack individually for each moment‐tensor component. The objective function for the source location is then formulated as the squared sum of those stacked components. The maximum value of the objective function corresponds to the estimated source location and origin time. Similarly, the corresponding stacked components at the estimated source location give the entire time history of the qualitative estimation of the moment tensor. We apply the method to synthetic data of various types of moment‐tensor sources computed for a complex and heterogeneous model, namely the Pyhäsalmi ore mine in Finland. We also test the method with the same data adding white noise up to 40% of the absolute maximum. Although the method is computationally intensive, it is fully automatic and can easily be adapted to parallel processing. The preliminary results show that the method is robust and reliable.