Morphological changes and future projections of the Getz Ice shelf, western Antarctica—A statistical and geospatial approach

Abstract

The study assessed the extent of the Getz Ice Shelf over a 19-year period using satellite data and divided it into three sectors. The average of rates (AOR), end point rate (EPR), and linear regression (LR) methods were employed to estimate the rate of change, with the LR method showing the strongest correlation. The analysis revealed a shrinkage rate of 42 m/year during February from 2003 to 2019. Over the last 17 years, recession was observed in 60% of transects, while progradation occurred in 40%. The recent decline in Getz ice shelf extent is closely linked to the record low sea ice extent in the Amundsen Sea sector. Predictions for 2024 and 2029 indicated progradation in Sector I and recession in Sectors II and III, as determined by LR analysis. The root mean square error values of transects in Sectors II and III showed good correlation with past positions and satellite-based observations of ice shelves. To validate the predicted ice shelf extent cross-verified with the satellite and predicted data from 2020 to 2022. These findings highlight the complex interactions between climatic forcings, such as wind speed, sea surface temperature (SST), and the Southern Annular Mode (SAM). Positive SAM and increased zonal winds can contribute to warm water upwelling near the Antarctic coast, impacting ice shelf extent. The relationship between ice mass loss and SST provides valuable insights into the dynamic processes of melting and progradation in the Getz Ice Shelf during February. Ocean warming plays a significant role in increased basal melting and changes in sea ice mass. The study emphasizes the significant impact of ocean-atmospheric factors on Antarctic ice shelf dynamics and highlights the necessity for ongoing satellite observations and enhanced comprehension of these processes to accurately predict future changes in Antarctic ice shelves.