Electrical resistivity of modern marine sediments from the Bering Sea

This study is concerned with the relationships between electrical resistivity and the bulk physical properties of sea-floor sediments. Electrical resistivity was measured in gravity-cored unconsolidated sediments from the Bering Sea. Resistivity ranged from 29.1 to 71.0 ohm cm at 25°C and irregularly increased 11 ohm cm in the first meter below the sediment surface, principally because of porosity changes. In situ resistivity may be greater than these laboratory values by a factor of 2 or 3. The formation factor F, which is the ratio of sediment resistivity to interstitial water resistivity, ranged from 1.57 to 3.70 and was related to porosity ϕ and wet bulk density ρ by the following expressions: F = 1.30ϕ−1.45 and F = 1.12ρ1.72 with errors of ±15 and ±10%. Within certain limits resistivity may be used to estimate other physical properties of the sediment.