Dome Fuji, Antarctica Core DF2 Dielectric Anisotropy Measurements

Dielectric anisotropy data of DF2 ice core were acquired as an indicator of the crystal orientation fabric. We measured dielectric anisotropy at 5 m intervals between the depths of 100 and 2400 m. At each sampling depth, a 1 m long ice core (two 0.5 m sections) was assessed with a 0.02 m step. Each ice core sample was formed into a slab shape with a thickness of 68-79 mm and width of 53-62 mm. We used an open microwave resonator, employing frequencies between 14 and 20 GHz. The open resonator was a semi-confocal type with a flat mirror and a concave mirror having a 250 mm radius of curvature, set 225 mm apart. The Gaussian beam at the sample insertion position between the two mirrors had a half-power diameter of 38 mm. The dielectric anisotropy values were volume-weighted averages within the volume covered by the Gaussian distribution of the beam. Dielectric anisotropy and its standard deviation were determined at intervals of approximately 0.5 m along the core sample, using 23 data points for each interval. The measurements were conducted at temperatures in the range of -30+-1.5 dgreeC in a cold room at the National Institute of Polar Researech, Japan.