GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 Integraton of 3D P and S velocity model in SeisComP real tme monitoring: an applicaton to Northern Italy F. Grigoli 1 , C. Rossi 2 , C. Cocorullo 2 1 University of Pisa, Italy 2 Seismix s.r.l., Italy The real-tme microseismic monitoring represents a fundamental point in evaluatng and managing the risks associated with industrial actvites for geo-resources exploitaton. SeisComP (Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences and gempa GmbH 2008), a sofware package developed by the German Research for Geosciences (GFZ), stands out as one of the most extensively utlized tools for seismic monitoring: it facilitates automatc data acquisiton and real- tme or post-processing. In this study, we illustrate a SeisComP optmizaton for real-tme data processing applied to microseismic monitoring of an Underground Gas Storage feld in Northern Italy. Our analysis encompasses two years of contnuous seismic data obtained from a seismic network consistng of 15 statons, including both surface and borehole sensors. To beter constrain the earthquakes’ locaton, frst, we applied a Joint Hypocenter and Velocity technique (Thurber, 1992; Kissling, et al. 1994) to compute a new P and S 1D velocity model for the gas storage feld area. Then, we derived a 3D P-wave velocity model at the reservoir scale by using migraton velocity data from a 3D seismic refecton survey. To obtain the 3D S-wave velocity model, we used an average Vp/Vs value derived from the 1D velocity model and well-logs. In the concluding phase, the diferent velocity models are compared by examining the earthquakes’ locatons obtained with each model. The results indicate a consistent enhancement in locaton accuracy (both in terms of RMS and waveform coherence) for events within the inner area when using the 3D model. For the other events, the earthquakes’ locatons computed with the optmized 1D velocity model are improved compared to those obtained by using the inital velocity model. This seismic processing routne represents a pioneering applicaton in Italy, demonstratng how a 3D velocity model can be fully integrated into real-tme microseismic monitoring operatons, in agreement with the recommendatons of the Italian Guideline for Microseismicity Monitoring in Industrial Actvites (Dialuce et al., 2014).