The electrical resistivity of sea ice was measured in situ at two locations in McMurdo Sound: 1km south of Scott Base and 1km northwest of Tent Island. Measurements were made at frequencies of 100Hz and 1000Hz using a Wenner array.This consists of four equally spaced electrodes in a line on the surface of the ice. The distance between the electrodes was varied from 0.05 m to 12.8 m so that the conductivity of the deeper layers of ice was progressively sampled. Cores were taken to determine the thickness of the ice and the variation of salinity with depth at both sites. Apparent resistivity curves and salinity and resistivity profiles were created.