Detailed quantification of glacier elevation and mass changes in South Georgia

• Published in: Environmental Research Letters
• Main Authors: Farías-Barahona, David, Sommer, Christian, Sauter, Tobias, Bannister, Daniel, Seehaus, Thorsten C, Malz, Philipp, Casassa, Gino, Mayewski, Paul A, Turton, Jenny V, Braun, Matthias H
• Other Authors: Regional Sea Level Change and Society - DFG, German Space Agency and Ministry of Economy
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2020
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; South Georgia Island
• Online Access: http://dx.doi.org/10.1088/1748-9326/ab6b32; https://iopscience.iop.org/article/10.1088/1748-9326/ab6b32; https://iopscience.iop.org/article/10.1088/1748-9326/ab6b32/pdf

Abstract 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 ∼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.