Thermoerosion of Frozen Sediment Under Wave Action

Abstract

Ice‐bonded sediment is present in tundra cliffs and gravel structures in the southern Beaufort Sea. Thermoerosion of the frozen sediment under wave action can be important in determining the rate of coastal retreat and the severity of erosion of a gravel structure. The thermal processes involved in the thermoerosion of the frozen sediment are examined assuming the transport capacity of the wave action exceeds its melting capacity. The location of the melting surface of the frozen sediment is determined by solving the heat conduction equation in the frozen sediment exposed to the wave action, which causes the convective heat transfer between the sea water and the frozen sediment. Analytical solutions are presented for simplified one‐dimensional problems. A two‐dimensional finite element method based on a fixed domain approximation is proposed to facilitate the numerical computation. The example computation made for a frozen gravel causeway indicates that the melting of the frozen gravel will occur rapidly under the assumed storm conditions if the melted sediment is removed by the wave action.