Detailed quantification of glacier elevation and mass changes in South Georgia

• Published in: Environmental Research Letters
• Main Authors: Farias-Barahona, David, Sommer, Christian, Sauter, Tobias, Bannister, Daniel, Seehaus, Thorsten C., Malz, Philipp, Casassa, Gino, Mayewski, Paul A., Turton, Jenny A., Braun, Matthias H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP Publishing Ltd 2020
• Subjects: Antarctic; The Antarctic; Antarctic Peninsula; South Georgia Island; Antarc*
• Online Access: http://nora.nerc.ac.uk/id/eprint/526564/; https://nora.nerc.ac.uk/id/eprint/526564/1/Farias-Barahona_2020_Detailed.pdf; https://iopscience.iop.org/article/10.1088/1748-9326/ab6b32/pdf

Most glaciers in South America and on the Antarctic Peninsula are retreating and thinning. They are considered strong contributors to global sea level rise. However, there is a lack of glacier mass balance studies in other areas of the Southern Hemisphere, such as the surrounding Antarctic Islands. Here, we present a detailed quantification of the 21st century glacier elevation and mass changes for the entire South Georgia Island using bi-static synthetic aperture radar interferometry between 2000 and 2013. The results suggest a significant mass loss since the beginning of the present century. We calculate an average glacier mass balance of -1.04 0.09 m w.e.a(-1) and a mass loss rate of 2.28 0.19 Gt a(-1) (2000-2013), contributing 0.006 0.001 mm a(-1) to sea-level rise. Additionally, we calculate a subaqueous mass loss of 0.77 0.04 Gt a(-1) (2003-2016), with an area change at the marine and lake-terminating glacier fronts of -6.58 0.33 km(2) a(-1), corresponding to similar to 4% of the total glacier area. Overall, we observe negative mass balance rates in South Georgia, with the highest thinning and retreat rates at the large outlet glaciers located at the north-east coast. Although the spaceborne remote sensing dataset analysed in this research is a key contribution to better understanding of the glacier changes in South Georgia, more detailed field measurements, glacier dynamics studies or further long-term analysis with high-resolution regional climate models are required to precisely identify the forcing factors.