Geetha Priya M , Raghavendra K R, Mahesh B, Rakshita C, Dhanush S, Sivaranjani S, Krishna Venkatesh, Narendra Kumar M, Alvarinho J Luis, Deva Jefflin A R

Surface melting in Antarctica can result in the formation of meltwater ponds and streams, which can encourage glacier basal sliding and ice flow; long-term severe surface melting can result in the formation of melt ponds and, eventually, supraglacial lakes (SGLs), raising the prospect of hydrofracturing. Measurements of these surface melting characteristics are useful for studying glacier and ice sheet dynamics and monitoring polar climate change. This work addresses a technical analysis of the dynamics of the Nivlisen ice shelf, East Antarctica, with a focus on multiple components such as melt ponds and SGL parameters (such as area, length, volume, and depth), seasonal surface melt extent, and surface ice flow velocity. For the austral summers of 2000-2023, data from the Landsat and Sentinel-1 have been used to analyze at both spatial and temporal scales. The overall area of melt ponds and SGLs remained relatively low (one square kilometers) during November and December from 2000 to 2014. For the austral summers of 2015-2023, a consistent melting pattern with increased formation of melt ponds and SGLs has been observed. Among the analyzed years, 2016, 2017, 2019, and 2020 have the greatest SGL depth. Maximum volume with progressive growth in the area in SGL was observed during 2008, 2016, and 2020. Understanding the relationship between velocity and basal melt is necessary to comprehend the dynamics of the ice shelf in terms of ice shelf stability and assess the influence of surface melt on seasonal ice velocity patterns. The data analysis showed that January had the most substantial melting, resulting in more significant velocity values. During 2000-2023, surface melt occurred in the southern and northwestern regions of the Nivlisen ice shelf. Our results emphasize the critical role of surface melt in driving ice shelf velocity. The results were validated using ground truth data collected over a melt pond in central Dronning Maud Land during the austral summer of 2022-2023 and verified with model-based results. The increase in depth and volume could significantly impact the integrity of the region's ice shelf. Surface melting conditions that are persistent and obvious will increase the formation of melt ponds and SGL, which accelerates ice flow and cause ice shelf destabilization. Continuous monitoring of the Antarctic shelves are necessary to access the impact of climate change.