refractor ambiguities are big problem in seismic refraction method especially in seismic engineering. there can be hidden subsurface geological phenomena such as hidden faults and shear zones which are not simply predicted by the travel-time graph or some geophysical methods. head wave amplitudes are used to show the resolution of refractor ambiguities and the existence of anisotropy in complex...

A limited seismic investigation of Ball Mountain Dam, an earthen dam near Jamaica, Vermont, was conducted using multiple seismic methods including multi-channel analysis of surface waves (MASW), refraction tomography, and vertical seismic profiling (VSP). The refraction and MASW data were efficiently collected in one survey using a towed land streamer containing vertical-displacement geophones ...

The seismic refraction technique provides a simplified characterization of relatively large volumes of the subsurface in 2-dimensional (distance and depth) profiles. Compression wave (p-wave) velocities, the typical measured geologic material parameter, are a function of the moduli of the various unsaturated material masses in the subsurface profile. In saturated media, p-wave velocities are in...

The refraction inverse problem was initially investigated by Herglotz (1907), Bateman (1910), and Wiechert and Geiger (1910) who applied Abel transforms for the inversion of seismic travel-times in radially varying media. For smoothly varying media in the absence of low velocity zones, this formulation provides an inverse solution which includes ray bending. In the presence of low velocity zone...

Seismic studies using well-logging, refraction, and reflection methods were carried out in 1965 in conjunction with a core-sample drilling project in the Ewa Coastal Plain, Oahu, Hawaii. The seismic well-logging technique gave a complicated velocity-depth profile, with higher velocities associated with reef limestone and lower velocities associated with mud deposits. The seismic refraction meth...

A method is demonstrated for recording and inverting in-line and broadside seismic refraction and reflection data to obtain three-dimensional structure and velocity information. This technique of spatial seismic refraction recording produces a superabundance of common ray intersections at the target horizon. The full power of the linear least-squares inversion method may be used in the overcons...

The ice content of the subsurface is a major factor controlling the natural hazard potential of permafrost degradation in alpine terrain. Monitoring of changes in ice content is therefore similarly important as temperature monitoring in mountain permafrost. Although electrical resistivity tomography monitoring (ERTM) proved to be a valuable tool for the observation of ice degradation, results a...

[1] In 2005 an extensive new seismic refraction data set was acquired over the central part of the Chicxulub impact crater, allowing us to image its structure with much better resolution than before. However, models derived from traveltime data are limited by the available ray coverage and the nonuniqueness that is inherent to all geophysical methods. Therefore, many different models can fit th...