Ground-based sea ice thickness profiles

This method returns the depth to the electrical conductivity horizon between the lower-conductivity sea ice and higher-conductivity sea water. We used a Geonics EM31 device in the so-called horizontal dipole configuration.

Transects were made by towing the EM31 in a sled or kayak with periodic measurements of snow thickness and GPS location. Most transects also include DGPS-derived surface elevation measurements. Ice thickness was derived from the EM31 measurements using a calibration from apparent conductivity to ice thickness determined locally in Barrow (Mahoney et al. 2007).