Sub-seasonal variability and multi-year trends in glacier area change and ice speed on the Antarctic Peninsula

Abstract. As the climate continuous to warm, glaciers on the Antarctic Peninsula (AP) are experiencing rapid dynamic changes, including accelerated rates of thinning, terminus retreat, and ice flow, all of which have significant implications for global sea level rise and climate feedback mechanisms. These glaciological changes unfold over varying timescales spanning from months to decades, necessitating temporally and spatially detailed monitoring. Here, we used sub-seasonal records of terminus area change (2013–2023) together with high-resolution satellite-derived ice surface velocity measurements (2014–2024) to investigate the evolution of 42 key outlet glaciers on the northern AP. We found that during the past decade, these glaciers underwent substantial but spatially heterogeneous changes in terminus position and ice flow velocity. Cumulative ice loss amounted to ~279 km², with 73 % of this loss occurring on the eastern side, particularly within the Larsen B embayment. By contrast, western glaciers showed smaller, more variable responses. Overall, 71 % of glaciers accelerated, though most eastern glaciers displayed slight trends of slowdown – except in the Larsen B region, where major calving events beginning in early 2022 were followed by drastic increases in velocity, with some glaciers more than doubling their flow speed. In addition, a seasonality analysis revealed widespread inter-annual variability: two-thirds of glaciers showed strong to very strong seasonal fluctuations in flow speed, and about half exhibited comparable signals in terminus change. Cross-correlation analysis further indicated that, for most glaciers, terminus area changes and ice velocity dynamics had only minimal influence on one another. These results highlight the spatially and temporally heterogeneous nature of glacier dynamics on the northern AP, suggesting that glacier change in this region is shaped by a combination of environmental drivers and glacier-specific factors operating on widely varying timescales. They underscore the need for detailed, high-resolution observations and continuous monitoring to improve the understanding of glacier evolution under ongoing climatic and environmental change.