Pore Occupancy of Ice

Abstract

Ice forms seasonally in mid‐latitude soils, and permanently as permafrost in arctic sediments. Ice blocks some of the pore space, altering the flow of both liquid water and gas. Here, we determine the equilibrium position of ice in a three‐phase ice/water/gas system by minimizing the free energy of the system. We show that ice will occupy the intermediate‐sized pores, and gas will occupy the largest pores. This has implications for (a) determining the flow behavior of water and gas through permafrost from simpler gas/water measurements, (b) determining the capillary pressure of gas and water in the presence of ice, and (c) determining the pressure of ice—a previously unknown variable.