Investigation of Evolution of the Arctic Shelf Cryolithozone by Mathematical Simulation

The dynamics of formation and degradation of permafrost rocks on the Arctic shelf during regression and subsequent transgression of the sea is under study. The processes under consideration have been simulated in terms of Stefan’s multifrontal problem, with variations in paleotemperatures of the open land surface and sea bottom and world-wide changes in sea level being taking into account. The shelf rocks are represented by a two-layer section with the upper part being more saliferous. To solve the problem, an effective numerical method was applied, which explicitly determines phase-transition boundaries. Based on the numerical experiments carried out for the Laptev-Sea shelf, the cryolithozone evolution in its various parts and the dynamics of setting up the nongradient temperature field in the process of bilateral permafrost degradation have been forecasted. In the last case, a break in permafrost continuity has been noted at the boundary of the rocks that are characterized by different temperatures of pore water freezing.