Multisource Satellite Altimetry Reveals Complex Elevation Dynamics at Klutlan Glacier in Alaska Between 2008 and 2024

Abstract

Assessing glacier elevation changes in rugged terrain remains a persistent challenge for satellite altimetry. This study integrated Jason-2, CryoSat-2, and ICESat-2 data to monitor surface elevation changes of the Klutlan Glacier in Alaska. A unified data processing framework was adopted to minimize systematic errors arising from differences in repeat cycle, footprint size, and orbital coverage. By implementing a repeat-track analysis on Jason-2 data, valid on-glacier observation points were expanded from 4 to 48. With CryoSat-2 as the primary baseline, systematic bias corrections were applied and multisource data were merged at crossover points to reconstruct a continuous elevation time-series spanning 2008–2024. The analysis revealed a systematic acceleration in glacier-wide mass loss after 2017, with the mean elevation-change rate increasing from –0.54 ± 0.83 m/yr (2010–2017) to –0.71 ± 1.22 m/yr (2017–2024). The ice tongue experienced a clear reversal in surface elevation change: before 2017, thinning prevailed in the 1150–1300 m bins while accumulation dominated in the 1300–1450 m bins; post-2017, universal thinning was observed across all elevation bins, with the most severe thinning of –6.70 ± 0.27 m/yr in the 1400–1450 m bin. From 2008 to 2024, Klutlan Glacier experienced deceleration and a spatial contraction of fast-flowing zones; after 2017, thinning expanded from the middle and lower reaches to the higher elevation main trunk, where a shift from slight thickening to thinning likely weakened upstream ice supply and, thereby, led to velocity declines across all centerline sectors. This study demonstrates that synergistic multimission altimetry provides a robust approach for elucidating spatiotemporal variations and dynamic mechanisms in mountain glaciers.