syngenetic permafrost growth is a mode of the growth of permafrost whereby additional material is deposited to a permafrost site during freezing conditions, causing the permafrost layer to build upwards. it is cited as an efficient mode of permafrost growth, compared with heterogenetic permafrost growth, which occurs when freezing temperatures penetrate into previously unfrozen ground of uniform composition. lunardini gives the basic formulas for permafrost generation under both modes.