An active source electrical conductivity sounding was carried out near the East Pacific Rise at 21¿ N. The average electrical conductivity from 2 km beneath the seafloor into the upper mantle was found to be about 0.004 S/m. There is no evidence of fully molten magma at a distance of 7 km from the spreading axis. The inferred conductivity with depth of the crustal rock is consistent with Brace's model of connected, seawater filled pores in rocks heated from beneath.