Abstract
Analytical long-profile models of fluvial incision are fundamental in
geomorphology, however, analogous models are missing for glaciers,
despite the fact that glaciers are an important and widespread agent of
physical erosion. We introduce a new analytical solution for coupled
glacial-fluvial networks under steady-state climate and uplift. We then
integrate this solution into a critical wedge orogen theory to explore
the effect of glaciation on the balance between climate, erosion and
orogen geometry. We find that the relief is closely tied to the
equilibrium line altitude (ELA) and that the geometry and average uplift
rate can respond significantly more sensitively to changes in climate
than critical wedge orogens dominated by fluvial erosion. Using this
observation, we suggest that the global lower ELA during glacial
maximums over the last few millions years could trigger narrowing of
critical orogens, with an associated increase in uplift rates within the
active orogen core.