Decadal glacier flow acceleration caused by upper ocean warming in the Antarctic Peninsula

• Widespread acceleration of glacier flow occurred since 2018, with the fastest reaching 4.04 ± 0.50% yr⁻¹ in this period. • Identifies 0–300 m upper ocean warming as the dominant driver of sustained glacier acceleration in the Antarctic Peninsula, distinguishing atmospheric and oceanic forcing roles. • Provides a quantitative basis for reassessing ice-sheet instability and sea-level rise projections under ongoing climate warming. Mass loss from the Antarctic Ice Sheet has increased sharply in recent decades, driven largely by dynamically imbalanced flow of marine-terminating glaciers. Previous studies have linked short-lived glacier speed-ups to surface meltwater drainage or episodic ocean intrusions, yet it remains unclear whether persistent ocean warming can maintain regional acceleration. Using a decade of Sentinel-1 observations (May 2015–April 2025), we quantify surface velocities for 101 glaciers draining into Beascochea Bay and demonstrate that dynamic imbalance and sustained ice flow acceleration now coexist at regional scale. Mean summer glacier velocities increased by 1.81 ± 0.65%, approximately 0.88% higher than winter month values, and peak summer speeds rose by 6.44 ± 0.74%. Widespread acceleration of glacier flow occurred since 2018, with the fastest reaching 4.04 ± 0.50% yr⁻ 1 in this period. Further analyses identify upper-ocean warming at 0–300 m depth as the dominant factor, linking sustained acceleration to shallow subsurface heat rather than atmospheric melt. These results reveal a decadal-scale transition from transient to ocean-associated glacier dynamics, in which ocean thermal forcing sustains long-term acceleration even as mechanical stability declines, thereby enhancing the Antarctic Peninsula’s contribution to sea-level rise.