Debris variability and velocity estimation using Electrical Resistivity Tomography and DInSAR techniques of Durung...

This study integrates Electrical Resistivity Tomography (ERT), Synthetic Aperture Radar (SAR), and DGPS measurements to characterize the glacier dynamics, subsurface conditions, and moraine stability of the Durung Drung Glacier in the northwestern Himalaya. ERT profiles reaching depths of ~ 45 m resolves a distinct three-layer subsurface architecture composed of a low-resistivity, water-saturated surface layer, an intermediate zone of frozen sediments containing discontinuous ground-ice lenses, and a high-resistivity crystalline bedrock unit. The absence of massive, continuous ice within both the lateral and terminal moraines combined with the presence of isolated frozen pockets indicates melt-out of earlier ice-cored moraine complexes. This transition from ice-cored to ice-free but partially frozen moraine material indicates sharp thermal sensitivity, increased subsurface hydrological connectivity, and a growing susceptibility of moraine structures to internal weakening under continued climatic warming. Surface ice-flow velocities derived using Sentinel-1 A/B DInSAR, SAR offset tracking, and COSI-Corr feature tracking range from 120 to 138 m a⁻¹, capturing spatial variations in glacier motion across the ablation zone. Complementary DGPS surveys document a progressive snout retreat of 14.93 ± 0.5 m (2018-2019), 16.62 ± 0.5 m (2019-2020), and 21.43 ± 0.5 m (2020-2022), confirming rapid frontal recession. The frontal retreat is also driving the expansion of the moraine-dammed lake, as greater meltwater discharge and reduced ice support allow the lake to enlarge against a weakening terminal moraine. Subsurface debris characteristics, ice-flow dynamics, and hydrological pathways, providing a strong framework for evaluating moraine stability and glacial hazards in high-mountain Himalayan environments.