oa Diffraction Stacking - The Role of Source Mechanisms

Localization of seismic events provides us valuable information about structures activated by tectonic stresses, geothermal or volcanic activity, reservoir stimulation, and other subsurface activities. In the last few years automatic stacking-based localization techniques that do not require any picking of phases, have become popular and widely-used localization tools. Localization results obtained by such techniques are influenced by various factors. In this work we illustrate that source mechanisms directly influence the form and resolution of a resulting image function. For this purpose, two numerical examples are presented. The first considered source type is a so-called compensated linear vector dipole source, which is typical for geothermal and volcanic areas. As the most seismic events can be best characterized by a combination of explosive, double-couple (DC) and compensated linear vector dipole (CLVD) components, localization of such a source mechanism is also illustrated.