1,2,3,- 1Chinese Antarctic Center of Surveying and Mapping, Wuhan University, Wuhan, 430079, China
- 2Key Laboratory of Polar Environment Monitoring and Public Governance (Wuhan University), Ministry of Education, Wuhan, 430079, China
- 3School of Geodesy and Geomatics, Wuhan University, Wuhan, 430079, China
- 4School of Earth Sciences, Zhejiang University, Hangzhou, 310027, China
The Antarctic Ice Sheet is a major contributor to present-day sea-level rise, with most mass loss occurring through ice shelves that regulate upstream ice flow via buttressing effect. Recent widespread ice-shelf thinning, enhanced calving, and structural weakening underscore the need for long-term observations to understand ice-shelf stability and potential tipping behavior. Pine Island Glacier and its ice shelf, located in the Amundsen Sea sector of West Antarctica, have experienced sustained acceleration, thinning, and retreat since the 1970s, making this system an ideal natural laboratory for investigating ice-shelf dynamic responses to climate forcing.
Here, we investigate the dynamic evolution and stability of the Pine Island Ice Shelf (PIIS) from 2014 to 2025 using multi-source satellite remote-sensing data. While the dynamics for the PIIS for the last decade are dominated by accelerating flow, the velocity time series also reveal a deceleration of the central PIIS between 14 March 2022 and 20 January 2023. Piglet Glacier, a major tributary of the PIIS, also experienced two distinct deceleration periods between 2023 and 2025. Our analysis demonstrates that ice flow in the central PIIS and Piglet Glacier is highly sensitive to mechanical coupling along shear margins, modulated by variations in the state and configuration of dense ice mélange. In the northern sector of the ice shelf, sustained thinning, loss of pinning points, rift propagation, and a major calving event collectively indicate progressive structural weakening, despite a limited dynamic response to date.
Overall, our observations indicate a transition toward increased structural vulnerability across the Pine Island Ice Shelf. These findings provide new observational constraints on ice-shelf stability, grounding processes, and transient deceleration mechanisms, with important implications for ice-sheet modeling and future sea-level projections.
How to cite: Chien, Y., Zhou, C., and Riel, B.: Dynamic evolution and emerging structural vulnerability of the Pine Island Ice Shelf, West Antarctica from 2014 to 2025, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-4638, https://doi.org/10.5194/egusphere-egu26-4638, 2026.
