2:00 PM - 2:15 PM
[S09-3-03] Seismic sources under tensional regime - TRM and DEM approaches
Seismic sources are most often modeled as shearing fracture processes (mode II and/or mode III fracturing) accompanied by complex frictional phenomena. Such approach has a solid support in field evidence for large natural earthquakes. Thus, the most of afford of describing seismic sources have concentrated on shearing-type models. However ,a situation is more complex
in case of anthropogenic siesmicity induced, for example, by mining. A large number of mining induced seismic events with significant volumetric (isotropic) component in the moment tensor solution have been reported suggesting that non shearing processes in seismic foci are not negligible. The sharing-like approach becomes even more problematic when micro-seismic events accompanying hydro-fracturing are concerned. In this case a tensional fracturing of reservoir rocks is highly desirable for engineering purpose and hydro-fracturing is design to meet this goal. However, in such a case to describe seismic/acoustic sources we cannot further on use a formalism developed for shearing-like sources – including tensional rupture mechanisms (mode I fracturing) is absolutely necessary.
In this presentation we discuss two different approaches to modeling non-shearing seismic/acoustic sources under tensional regime based on two well developed approaches. The first one, is based on the time reversal imaging (TRM) of acoustic sources. The second approach relies on a direct ˋˋbrute-force'' simulations of material fragmentations based on the discrete element method (DEM).
in case of anthropogenic siesmicity induced, for example, by mining. A large number of mining induced seismic events with significant volumetric (isotropic) component in the moment tensor solution have been reported suggesting that non shearing processes in seismic foci are not negligible. The sharing-like approach becomes even more problematic when micro-seismic events accompanying hydro-fracturing are concerned. In this case a tensional fracturing of reservoir rocks is highly desirable for engineering purpose and hydro-fracturing is design to meet this goal. However, in such a case to describe seismic/acoustic sources we cannot further on use a formalism developed for shearing-like sources – including tensional rupture mechanisms (mode I fracturing) is absolutely necessary.
In this presentation we discuss two different approaches to modeling non-shearing seismic/acoustic sources under tensional regime based on two well developed approaches. The first one, is based on the time reversal imaging (TRM) of acoustic sources. The second approach relies on a direct ˋˋbrute-force'' simulations of material fragmentations based on the discrete element method (DEM).