Analysis of fine-scale dynamics of the Drygalski ice tongue in Antarctica using satellite SAR data

ABSTRACT

This study focused on the analysis of the time variability of the morphology of the Drygalski ice tongue (DIT), Antarctica, using – for the first time – satellite synthetic aperture radar (SAR) images. A time series of Sentinel-1 interferometric wide swath SAR imagery collected from 2016 to 2021 is considered and an unsupervised methodology, based on a global threshold constant false alarm rate approach, is used to extract the boundary between the DIT and the surrounding ice-free/ice-infested sea water. The most prominent rifts/fractures identified on the extracted profiles and the ice front are selected to analyse the DIT time variability. The feature tracking allows deriving information on the morphological evolution of the DIT, including the annual displacement and average surface velocity. Experimental results show that the DIT ice front calls for a relatively stable motion trend towards the sea with an average surface velocity of about 670 m per year. Our outcomes show a fairly good agreement with similar studies appeared in the scientific literature, which are mostly based on optical imagery.

KEYWORDS:

• Drygalski ice tongue
• Antarctica
• SAR
• Sentinel-1
• ice edge extraction
• surface velocity

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partly funded by the Italian National Program for Research in Antarctica (PNRA) through the ‘Sea ice-Wave Interaction Monitoring for Marginal Ice NaviGation’ (SWIMMING) project [grant PNRA_00298] and by the European Space Agency (ESA) under the ESA-MOST (Chinese Ministry of Science and Technology) Dragon-5 cooperation project ‘Monitoring hArsh Coastal environments and Ocean Surveillance using radar remote sensing’ (MAC-OS), [grant 57979].