The use of a towed, direct-current, electrical resistivity arrayfor the classification of marine sediments

摘要

Model studies indicate that the DC electric resistivity techniqueis feasible for sediment classification and layer structuring. Aprototype array was built to test the hypothesis that such a techniquecan be used in an underway mode in the marine environment. A 60-m,inverted array was towed both on and off the seafloor with electrodespacings appropriate for a penetration depth of 10 m below the seafloor.Three different bottom types, namely mud, gassy mud, and sand, weresurveyed in the Mississippi Sound using the array. Ground truth wasprovided with an acoustic seafloor classification system, CTD(conductivity, temperature, and depth) casts, and numerous sedimentcores. Data were analyzed using SUBVERT, an inversion routine adaptedfor an IBM-PC AT