Using surface-based electrical, magnetic, electromagnetic, gravity, and ground-penetrating radar measurements, Southwest Research Institute (SwRI) conducts integrated, high-resolution, geophysical surveys to characterize subsurface geological environments. These noninvasive measurements provide data at a variety of scales, from the regional geologic setting to the site-specific level. Scientists rapidly and accurately locate, map, and characterize subsurface geological and hydrogeological features and anomalies using:
- State-of-the-science instrumentation
- Improved data processing methods
- Advanced geolocation techniques
More than 25 projects with durations of one day to several weeks or more have been completed to date throughout the United States and the Caribbean.
Applications of Near-Surface Geophysics
SwRI scientists have applied geophysical measurements and survey techniques to:
- Aquifer characterization
- Delineation of depth to groundwater
- Water quality (salinity)
- Subsurface detection and mapping of geologic structure (fault/lithology detection and delineation)
- Delineation of buried igneous features (e.g., dikes and volcanoes)
- Delineation of buried metal objects, pipelines, and electric utilities
- Subsurface cave and karst feature detection
- Resource assessment for aggregate quarry sites (rock and unconsolidated sediments)
- Leaking dam evaluation
- Soil evaluation for geotechnical design of foundations
Scientists use an integrated electromagnetic and differential global positioning system (GPS) to rapidly and accurately collect ground conductivity data. A contour map of ground conductivity shows the location of resistive sand and gravel bodies (yellow to red colors) in relation to conductive clay and silt sediments (blue and green colors) in the shallow subsurface.
Scientists used DC electrical resistivity to determine the depth of a sign post pedestal located in a limestone terrain. The sign post was emplaced in a supporting metal caisson, which appears as a conductor (blue colors) in the resistivity profiles. The surrounding limestone appears as a resistor (orange to purple colors).
electrical resistivity • electromagnetics • environmental geophysics • geophysics • gravity • ground conductivity • ground-penetrating radar • induced polarization • magnetics • Near-Surface geophysics resistivity • surface-based geophysics • transient electromagnetics