Time domain surface electromagnetic soundings, borehole induction logs, and other borehole logging techniques are used to construct a realistic model for the shallow subsurface hydraulic properties of unconsolidated sediments in south Florida. Induction logs are used to calibrate surface induction soundings in units of pore water salinity by correlating water sample specific electrical conductivity with the electrical conductivity of the formation over the sampled interval for a two‐layered aquifer model. Geophysical logs are also used to show that a constant conductivity layer model is appropriate for the south Florida study. Several physically independent log measurements are used to quantify the dependence of formation electrical conductivity on such parameters as salinity, permeability, and clay mineral fraction. The combined interpretation of electromagnetic soundings and induction logs was verified by logging three validation boreholes, confirming quantitative estimates of formation conductivity and thickness in the upper model layer, and qualitative estimates of conductivity in the lower model layer.
|Title||Integrating surface and borehole geophysics in ground water studies: An example using electromagnetic soundings in south Florida|
|Authors||Frederick Paillet, Laura Hite, Matthew Carlson|
|Publication Subtype||Journal Article|
|Series Title||Journal of Environmental & Engineering Geophysics|
|Record Source||USGS Publications Warehouse|
|USGS Organization||Toxic Substances Hydrology Program|