This work is devoted to the theory of joint interpretation of multimethod geophysical data and its application to the solution of real geophysical inverse problems. The targets of such joint interpretation can be geological bodies with an established dependence between various physical properties that cause anomalies in several geophysical fields (geophysical multiresponse). The establishing of...

Geophysical studies over Kartchner Caverns State Park mapped structure and groundwater patterns beneath valley alluvium and determined the geophysical expression of the caverns at the surface. Three techniques were employed: electromagnetics (EM), gravity, and natural potential (NP). Electromagnetic traverses in the area failed to detect the voids, owing to the very low conductivity of the carb...

We apply the CIP (Cubic Interpolated Profile) scheme to the numerical simulation of the acoustic wave propagation based on characteristic equations.The CIP scheme is based on a concept that both the wavefield and its spatial derivative propagate along the same characteristic curves derived from a hyperbolic differential equation. We describe the derivation of the characteristic equations for th...

We present a Newton-CG method for full-waveform seismic inversion. Our method comprises the adjoint-based computation of the gradient and Hessianvector products of the reduced problem and a preconditioned conjugate gradient method to solve the Newton system in matrix-free fashion. A trust-region globalization strategy and a multi-frequency inversion approach are applied. The governing equations...

Ground Penetrating Radar (GPR) is an effective and practical geophysical imaging tool, with a wide set of applications in geological mapping of subsurface information. This research study aims at determination of the geophysical parameter differences in the subsurface geological structures and construction of a 3D fracture model. GPR and resistivity methods were applied to detect the unstable t...

A critical problem in inversion of geophysical data is developing a stable inverse problem solution that can si­ multaneously resolve complicated geological structures. The traditional way to obtain a stable solution is based on maximum smoothness criteria. This approach, however, provides smoothed unfocused images of real geoelectri­ cal structures. Recently, a new approach to reconstruc­ tion...

Geophysical site characterization investigations at fuel spill sites have been generally guided by a working hypothesis Ž . which assumes that the light non-aqueous phase liquids LNAPL are a fully saturating phase of intrinsically very high electrical resistivity. Using observations from other related sciences, and contrary geophysical observations, a different model is developed which treats t...

Elevation information plays a crucial role in simulations of geophysical flows providing the slope and curvature information required to solve a series of differential equations. Digital Elevation Models (DEMs) used as simulation input diverge in resolution, acquisition time and generation methodology. When more than one elevation data set is available, they can be analyzed to provide an estima...

An analysis of a passh'e seismic method for subsur­face imaging is presenled. in which ambienl seismic noise is em­ployed as the source of iIIu,;"ination of undergro~nd scal~erers.The imaging algorithm can ,"corporate new data mto the '!'lagein a recursive fashion, which causes image background nOise todiminish over time. Under the assumption of spatially-incoherentambie...

For tomographic imaging of a single physical parameter, the electrical conductivity, a number of well-proven techniques are available. In this project, we combine geoelectric methods (direct current DC), transient electromagnetics (TEM), natural-source magnetotellurics (MT) and controlled-source magnetotellurics (CSMT) (see Fig. 1). The resolution power of the individual methods depends on the ...