Seismic Energy Generation and Partitioning into Various Regional Phases from Different Seismic Sources in the Middle East Region
Final rept. 1 Jan 2004-30 Jun 2007
GEOPHYSICAL INST OF ISRAEL HOLON (ISRAEL)
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The project was focused on studying, experimentally, features of seismic energy generation and partitioning of P and S waves from different explosive seismic sources, at near-source and regional distances, in the time and spectral domain. An extensive database of Ground Truth single-fired explosions was created. The explosions selected contain a broad variety of design features buried and surface sources, tamped and decoupled shots, large diameter 0.5-0.8m borehole and near-spherical cavity charges, charge weight 100-32500kg, depth 14 62m, scaled burial depth 1.0-3.9mkg13, emplacement rocks alluvium, basalts, marls and geological settings. The highlight of this project was the source phenomenology experiments Decoupling and Depth-of-Burial DOB explosion series at the phosphate quarry Oron, Negev. A special technology was used for creation of large cavities up to 3.5 m at different depths, to accommodate large near-spherical ANFO charges. Extensive observations in the near-source zone 100-800 m and remotely up to 350 km demonstrated signal characteristics and energy generation features decoupling factors were estimated. The design and configuration of the Oron DOB experiment were preferable in design to the previous Balapan DOB experiment 1997 media homogeneity, small aspect ratio 1, full containment and small separation 200 m of the shots. The crossover point of spectral dominance at 10 Hz for different depth shots, observed at ranges 0.2-230 km, was remarkably consistent with the MuellerMurphy source model predictions.