Progressive changes in geometry and dynamics of the Northern Pine Island Ice Shelf, West Antarctica

The Pine Island Ice Shelf can be analysed within three distinct sectors: northern, southern, and central. Dynamics within the Northern Pine Island Ice Shelf (N-PIIS) remain less understood than those of the Central Pine Island Ice Shelf. Using satellite imagery and data, we investigate changes in the N-PIIS, including ice-front position and pinning-point evolution since 1973, annual ice velocity since 2014, surface elevation since 2018, rift propagation events in 2022 and 2025, and polynya activity from 1986 to 2026. Our results show an overall reduction in ice-shelf area, with increased calving following the loss of pinning points and reduced protection by landfast sea ice against ocean swell. Velocities of grounded and floating ice have increased. Polynya formation within the ice shelf may promote disconnection from the ice sheet and reduce lateral buttressing. Surface elevation changes and the redistribution of pinning points indicate ongoing thinning. Newly formed rifts are likely to promote further calving events. Our observations document continued thinning, frontal retreat, pinning-point loss, and rift propagation at the N-PIIS. This study provides critical new insights into the evolving stability of the N-PIIS and highlights the importance of continued monitoring to anticipate potential disintegration.