A novel framework for detecting and monitoring Antarctic active subglacial lakes using multi-source remote sensing data

Beneath the Antarctic Ice Sheet, active subglacial lakes act as dynamic storage–release nodes that modulate basal water pressure, influence ice flow, and regulate freshwater delivery to grounding zones. However, inventories and time series derived from single sensors remain incomplete due to limited spatial coverage, short mission lifetimes, and cross-sensor inconsistencies in sampling geometry and accuracy. Here we present a continent-wide, multi-mission framework that integrates three decades of satellite altimetry with high-resolution REMA strip DEMs to detect and monitor active subglacial lakes. We harmonize reprocessed ERS-1/2 and Envisat radar altimetry, ICESat and ICESat-2 laser altimetry, and CryoSat-2 swath measurements through local annular co-registration and a crossover-zone representativeness correction, enabling internally consistent, lake-scale elevation change estimates across sensors. The approach resolves subtle elevation variability, refines outlines delineation, and reconstructs multi-decadal (>30 years) filling–drainage histories. Applied to the Byrd Glacier basin, the framework increases the number of confirmed active lakes from 23 in existing inventories to 74, including 51 newly identified systems, and delivers refined outlines and time series for each lake. The resulting records reveal structured lake–lake interactions, motivating a process-based classification of cascading behavior into serial cascades, parallel co-variation, and terminal confluence. Our results indicate that observational incompleteness remains a primary limitation on Antarctic subglacial hydrology, and demonstrate that systematic multi-mission fusion can substantially improve detection, connectivity inference, and quantification of storage–release variability, providing stronger observational constraints for linking basal hydrology to ice dynamics and improving ice-sheet projections.