Geophysical Assessment of Deep Karst in Dam in Florida Using the Multi-Electrode Resistivity Implant Technique (MERIT)

The use of geophysical assessment of dams in deep karst environments can yield valuable information for such complex geology. One of the most used methods in the assessment of dams and karst is electrical resistivity (ER). ER has progressed from 2D resistivity curves to inversion of complex array patterns that produce image. There are however limitations to the current data collection and inversion methodology that prevents higher quality images. These limitations are based on the geometry of array and data collection that results in trapezoidal inversion data set with decreasing data at depth.

This is due to as electrode spacing i.e. 1a, 2a, 3a, etc. increases, the number of measurements decreases for each progressive deeper data level. This is a fundamental limitation of the technique. This results with an inversion of progressively less data the deeper the survey. The bottom third of the surface ER represents only 10.5% of the…