Climatological and geological drivers of glacier retreat patterns in Marian Cove, King George Island: A remote sensing study from 1956 to 2022

The tidewater glacier in Marian Cove has retreated substantially toward the coastal cliffs over the past six decades. Using 19 satellite and aerial images from 1956 to 2022, we quantified frontal changes along 17 transects defined by glacier orientation and topography. The glacier exhibited a non-linear retreat pattern, alternating between phases of rapid retreat, slower retreat, and short advances. Mean retreat rates fluctuated from −10.8 to 178 m year −1 over the study period. From 1956 to 1978, the terminus remained stable while grounded on a shallow sill, but detachment from this topographic control initiated sustained retreat. The onset of major retreat coincided with a transition from negative to positive Southern Annular Mode (SAM) anomalies, which enhanced atmospheric warming and promoted oceanic heat delivery. Retreat accelerated during positive ocean and air temperature anomalies, whereas cooler phases slowed retreat. Variability across transects was strongly linked to bathymetry and vertical temperature stratification. Time series of surface elevation revealed land ice thinning after 2017, corresponding to the rapid retreat observed between 2017 and 2019. By integrating the longest record of glacier frontal change in Marian Cove with environmental observations, this study demonstrates how coupled fjord geometry–ocean–atmosphere interactions govern retreat behavior. These findings improve understanding of the sensitivity of tidewater glaciers in the northern Antarctic Peninsula under climate change.