High basal melting rates within high-precipitation temperate glaciers

Abstract

The role of basal melting within high-precipitation temperate glaciers represents a significant gap in understanding glacier melting processes. We use a basal melt equation to calculate geothermal and frictional heat-induced basal melt and develop an equation to calculate the rainfallinduced basal melt for Franz Josef Glacier, New Zealand, a high-precipitation, temperate glacier. Additionally, we calculate basal melt due to heat dissipation within water and ice. Data collated from published information on glacier dynamics and climate station readings show that total basal melt contributes on average ∼2.50ma-1 over the lower to mid-ablation zone (300-1500ma.s.l.), which is equivalent to >10% of the total ablation for the glacier. This indicates that basal melting is an important component of mass balance for high-precipitation, temperate glaciers.