Antarctic ice shelves are being affected in an increasing number of ways through warmer oceans. The increased warmth in the oceans causes a process known as basal melting, which increases the speed of movement of the ice sheet and decreases back stress on grounding lines. Therefore, it is important to understand what factors affect where a grounding line lies so that researchers can be able to better predict the future stability of ice shelves and the resulting increase in global sea levels.This paper presents the first fully automated approach using Sobel edge detection combined with dominance analysis to detect grounding line hinges continuously from SAR interferometric displacement fields. This was done using 16 months of Sentinel-1 data from the Fimbul Ice Shelf. It also demonstrates that the authors’ Sobel edge detection algorithm achieved a 71.2 percent variance correlation coefficient with independent validation (κ = 0.87).The results of the authors’ univariate linear regression model demonstrated that none of the tidal (p = 0.702), seasonal (p = 0.07), or basal melt (p = 0.157) were individually statistically significant at n = 8. Conversely, the authors’ multivariate analysis showed that the combination of all three types of forcing explained 71.2 percent of the variation in hinge position, with basal melt explaining the most amount of this variation (44.5%), followed by seasonal variability (38.6%), and tidal variability (16.9%).Most importantly, the fact that none of these variables were individually statistically significant means that these findings will need to be validated with longer time-series (>3-5 years, >20 pairs) before any conclusions about climate sensitivity can be drawn.
We have placed both our Open-Source Algorithm and processed data onto the public repository (Zenodo) to allow the community to monitor Antarctic Ice shelf dynamics, as well as assess cryospheric hazards.
Data and code
All data and analysis scripts are openly available on Zenodo: https://doi.org/10.5281/zenodo.18714571
Submitted to Advances in Space Research.
Author: Shobha Mourya Dumpati, FGS, FRGS
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