Hydraulic transmissivity inferred from ice-sheet relaxation following Greenland supraglacial lake drainages

Abstract Surface meltwater reaching the base of Greenland Ice Sheet transits through drainage networks, modulating flow ice sheet. Dye and gas-tracing studies conducted in western margin sector sheet have directly observed efficiency to evolve seasonally along pathway. However, local evolution systems further inland, where thicknesses exceed 1000 m, remains largely unknown. Here, we infer system transmissivity based on surface uplift relaxation following rapid lake events. Combining field observations five events with a mathematical model laboratory experiments, show that decreases exponentially time, as water blister formed beneath drained permeates subglacial system. This deflation obeys universal law timescale reveals hydraulic indicates two-order-of-magnitude increase (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m 3 215 90.2 ) melt season progresses, suggesting significant changes basal hydrology lakes driven by seasonal input.