Low‐Frequency Polarization of Blank Ice Features in Solid Rocks

Abstract For hydrogeological management of seasonally frozen soils, or permafrost, the quantification of ice and water content is key. Changes in electrical conductivity are commonly used to monitor ice‐to‐water ratios but hard rocks, ice and air are all highly resistive materials. The high‐frequency polarization of ice (kHz range) offers a suitable alternative to the conductivity, but field investigations at such frequencies are still challenging. Here, we demonstrate the polarization of blank ice features in solid rocks at low frequencies (1–100 Hz). We identify two polarization effects: (a) an increase in the response due to the polarization of charges in the electrical double layer formed at the ice‐water‐rock interface; (b) an even larger response due to the non‐equilibrium freezing potential taking place during ice formation. We demonstrate that these effects can be used to image ice features, for instance, during ground‐ice formation and degradation.