Mechanisms of earthquakes and induced seismic events are frequently found using the moment tensor description rather than the traditional double couple (DC), as it allows for nonshear source phenomena. However, non-DC source components are sensitive to event mislocations and inexact velocity models of the crust. Inaccuracies such as these can generate spurious non-DC components in the mechanism, which should be taken into account during the interpretation. We perform a synthetic case study simulating seismic observations at Soultz-sous-Forêts, Alsace, hot dry rock (HDR) site. Synthetic P and S amplitudes for several shear-tensile source models are inverted, assuming hypocenter mislocation and velocity structure mismodeling in several types of station coverage. Satisfactory reconstruction of the source mechanism is achieved, except for rather extreme model simplification and extremely poor station coverage. Thus, our results suggest that non-DC mechanisms can be successfully resolved in local studies with reasonable station configuration, when errors in event location and velocity profile are realistic.

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