Stochastic Simulations of Bed Topography Constrain Geothermal Heat Flow
and Subglacial Drainage near Dome Fuji, East Antarctica
Abstract
Dome Fuji, inland East Antarctica is one of only few regions where
1.5-Ma old ice can be preserved for investigating the mid-Pleistocene
Transition. We used stochastic simulation and various radar datasets to
generate a bed topography ensemble with the continuous, realistic
roughness necessary to assess basal conditions. Ensemble analysis
reveals the magnitude and spatial distribution of topographic
uncertainty, facilitating uncertainty-constrained assessments of
subglacial drainage and topographic adjustments to geothermal heat flow.
We find that topographic variability can lead to widespread local
geothermal heat flow variations of ± 20% the background value, which
aggregate to raise the regional value and suggest previously
underestimated distributions and rates of basal melting. We also find
that survey profile spacing has an increasing influence on topographic
uncertainty for rougher bed, deriving an empirical relationship that
could guide future survey planning based on uncertainty tolerance.