Dielectric Profiling (DEP) of the North Greenland Ice Core Project (NGRIP1) core were recorded in the field during the 1996-1998 field seasons with the DEP device described by Wilhelms et al. (1998). The permittivity and conductivity of DEP data are calculated by their respective densities and conductivities (Wilhelms, 2005). The resolution of DEP data is 5 mm depth intervals. The DEP was not processed at a consistent temperature due to the varying temperature in the field seasons. For more information on the calibration procedure see Mojtabavi et al, 2020.We used 3.15 (permittivity) for deeper than 100 m depth (based on the radar modelling results).