Electrical Conductivity of Aqueous Magnesium Sulfate at High Pressure and Low Temperature With Application to Ganymede's Subsurface Ocean
Yilong Pan, Wenjun Yong, Richard A. Secco
Abstract
Abstract Ganymede has strong evidence of a subsurface ocean primarily composed of MgSO 4 . We conducted experimental measurements of the electrical conductivity of aqueous MgSO 4 at 200–1,200 MPa and 243–295 K in a multianvil press, simulating the high‐pressure and low‐temperature (HPLT) conditions of Ganymede's subsurface ocean. A numerical model is proposed with log σ = − 3.1605+940.931/ T +0.8986log c +2logΛ 0 − log(5Λ 0 +2695 c 1/2 ) , where σ is electrical conductivity in S/m, T is temperature in K, c is molar concentration in mol/L, and Λ 0 is limiting equivalent conductance in S·cm 2 ·equiv −1 . We used this model to generate electrical conductivity curves up to 500 km deep in Ganymede and found that the values are lower than previously predicted. Our novel experimental methods demonstrate access to the HPLT environment of liquid samples that expands our ability for experimental simulation of icy ocean worlds in the outer solar system.