CREWES has initiated a physical-modeling project focused on acquiring seismic data suitable for VVAZ and AVAZ analysis. Using sections of orthorhombic phenolic material and isotropic acrylic plastic, we have fabricated three slabs with orthorhombic anisotropy of different geometries. Immersing one of these orthorhombic slabs in water produces a two-layer velocity model. Placing an isotropic acrylic plastic slab above the first slab produces a three-layer velocity model. We used the U of C Seismic Physical Modeling facility to record CMP gathers files along many azimuth angles φ over these models. Picked arrival times and estimated amplitudes from reflections off the orthorhombic layer for these azimuths exhibit VVAZ and AVAZ behavior. Upon request, these model data will be available to our sponsors for further analysis.
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