Modelling subsurface heat flow in permafrost during a marine transgression in the Western Laptev Sea

摘要

Most submarine permafrost is relict terrestrial permafrost that was inundated by seawater as a result of sea level rise and/or coastal erosion. The marine transgression brings about a change from sub-aerial to submarine boundary conditions for permafrost: sea bottom temperature is generally warmer than ground surface temperature, and salt water infiltration thaws pore space ice. Permafrost degradation rates in the near-shore zone (< 10 m water depth) are complicated by sedimentation, water column heat and mass transport, sea ice dynamics (especially the timing and duration of bottom-fast ice) and diffusive transport processes within the sediment column. As a result of the interaction between these processes, the transition of terrestrial permafrost to offshore permafrost remains poorly understood [Taylor et al., 1996]. This study focuses on modelling results for this transition.