A Model for Variations in Gelifluction Rates with Temperature and Topography: Implications for Global Change

ABSTRACT

A model is proposed for gelifluction rates, in terms of active layer depths and sub-surface runoff. It is concluded that the flow of soil during melting can generally be assumed to be under saturated conditions, so that active layer depth is the dominant driver. Erosional slope profiles produced by gelifluction should be convex, with no tendency for small hollows to enlarge into valleys at any scale. This model has been applied, using a global database of monthly climate, to estimate regional variations in gelifluction rates under current conditions, and with both increases and decreases in mean temperatures. It is concluded that wide bands, roughly between 40–65°N and S, should have experienced a period of very intense gelifluction during the postglacial warming.