PROCESSING AND INVERSION OF REFRACTION AND WIDE-ANGLE REFLECTION DATA FROM THE 1986 NEVADA PASSCAL EXPERIMENT

Averaged, one-dimensional velocity models for the crust beneath the Basin and Range in western Nevada were derived by inverting τ(p) composites extracted from slant stacks of refraction and wide-angle reflection data. A combination of high-cut filtering in the frequency domain with coherency filtering in the (p, τ) domain has proved effective in smoothing severe static shifts due to lateral heterogeneities and suppressing artifacts due to spatial aliasing. The combination of low average P and S wave velocities with a high average Poisson's ratio in the upper half of the crust is consistent with the presence of fluid-filled cracks. Results highlight the need for three-component recording to better resolve shear wave velocity structure. -from Authors