GEOVision provides sub-surface imaging capabilities that are used in a variety of field applications. Because geology, target properties, and other site specific factors can vary widely, no single geophysical technology will work well in all areas. In many situations, the use of mulitple technologies will yield the best possible target information. GEOVision maintains a comprehensive inventory of geophysical instruments in order to provide the best method, or combination of methods, for a particular job. These methods include:
|Electromagnetics: EM methods provide a means to measure the electrical conductivity of subsurface soils, rock and groundwater as well as delineating buried metal objects such as utilities, buried drums and UST’s. EM methods provide a cost effective survey technique to cover large areas, but are susceptible to cultural noise and highly conductive near-surface soil conditions.
Magnetic: Magnetic methods are very effective at locating buried metallic objects such as UST’s, abandoned oil wells, and utilities.
|Resistivity: Although more expensive than EM techniques, newer state of the art (24-bit) instrumentation now offers higher resolution for soil studies, plume definition, void detection and groundwater studies.|
|Ground Penetrating Radar: GPR has long been used to find UST’s buried trenches and utilities. In recent years, GPR has become a commonly used method to locate rebar, tension cables and conduits embedded in reinforced concrete structures. With digital versions, deeper voids, subsidence features, and plume delineation can be resolved. Application of seismic data processing and 3D imaging to digital GPR data can enhance data resolution and make GPR data more easy to interpret and understand.|
|SASW: Spectral Analysis of Surface Waves An innovative method for measuring near surface shear wave velocities.|
|Vs30: A very cost effective method for determining the average shear wave velocity in the first 30 meters of the sub-surface|
|PS Suspension Logging: A very accurate borehole technology for measuring P and S-wave velocities.
|Construction Vibration Monitoring:|
|Blast Vibration Monitoring:|
|Seismic Refraction P-wave: Refraction surveys are the most cost effective method for mapping bedrock surfaces. Can be performed with both Vibroseis and Impulsive sources.|
|Seismic Refraction S-wave: Shearwave refraction techniques can be employed to define voids under concrete and rebar and along pipelines and sewers, etc.|
|Seismic Reflection P-wave: P-wave reflection techniques can be used to map structures, faults, lithology, reservoirs and mineral deposits.|
|Seismic Reflection S-wave: Shearwave reflection techniques can provide accurate soil stratigraphy, near-surface faulting, void detection, bedrock topography and channel identification.|
|Borehole Geophysics: Useful in well-to-well lithology correlation, identifying fractures, groundwater velocity through fractures and calibrating depth conversions for seismic.|
|Marine Seismic: Define sub-bottom features and map subsurface layers beneath water. Applications include: river crossings (i.e. horizontal drilling), pier and caisson construction and mineral exploration.|
|Marine Multi-beam: Define subsurface hazards and marine construction impediments. Transducer and marine magnetometers can prove a cost-effective survey technique to map sediments and define utility locations.|