Complex relationships between surface topography, ground motion, and cover sediments in covered karst, west-central Florida, USA

Sinkhole processes can be more complicated than vertical drainage or collapse of sediments into an underlying limestone void. To better understand the relationships between surface and karst structures, geodetic geophysical methods were applied to high-resolution mapping active sinkhole features in covered karst, west-central Florida, USA. Cracks a pool house at Sandhill Scout Reservation prompted subsurface investigations grassy open field with distinct ~60-m diameter topographic low west area. Beneath smooth low, ground-penetrating radar (GPR) limited penetration (up 6 m depth) shows incongruent smaller-scale (~5–20 m) variability horizon draping surface. Electrical Resistivity Tomography (ERT) profiles provide broader overview system (to depths ~25–36 show possible voids bedrock beneath local high. Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) analysis ~2 yr TerraSAR-X satellite data from two corner-reflectors installed reveals 1 mm/yr subsidence rate on flank but stability its center. This suggests that has halted central may occurring smaller scales elsewhere within survey The suggest non-vertical fluxes sediment significantly topography relative heterogeneities activity migrates complex systems. Our results also illustrate benefits corner reflector installations for resolving vegetated environments. 1-mm/yr motion could not resolved InSAR before installation.