Ice thickness measurements and volume estimates for Znosko glacier (Antarctica) using Glabtop model

Abstract:

Around the world there is a consensus of the importance of knowledge the ice thickness distribution and total ice volume for estimating future glacier change for both glaciological and hydrological application, especially the Polar Regions for being important regulators of the global climate system and response rapidly to climate change. This work aimed to estimate the ice thickness distribution and total ice volume of Znosko glacier (King George Island, Antarctic Peninsula) using Glacier Bed Topography (Glabtop) model and ground based data. Ground penetrating radar (GPR) measurements were collected in two field campaigns (2019-XXVI and 2020-XXVII Peruvian Antarctic Operation). GPR measurements were used to validate, calibrate (shape factor) and improve the accuracy of the ice thickness distribution model. The ice thickness distribution is not uniform over the glacier, which varies from 0 to 155 m. We compare the combined effects of different (resolution) digital elevation models and shape factor values on the derived ice thickness, concluding that both are necessary for a better estimation. The total stored ice volume of Znosko glacier in 2020 is estimated to be 0.078 km³ (uncertainty range of 30%). Additionally, the model bounded areas in the bedrock topography below sea level, as a sign of future lakes formation. The results of this work contributes to a better understanding of accuracies and limitations of modeled ice thicknesses using Glabtop model an improved knowledge of the subsurface topography of Znosko glacier.