Contrasting responses of land-terminating glaciers to recent climate variations in King George Island, Antarctica
| Autor: | Jeffrey D. Auger, Bijeesh Kozhikkodan Veettil, Cleiva Perondi, Kátia Kellem da Rosa, Jefferson Cardia Simões |
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| Rok vydání: | 2020 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences 0211 other engineering and technologies Ice field Elevation Climate change Geology Glacier 02 engineering and technology Present day Oceanography 01 natural sciences Paraglacial Glacial period Physical geography Meltwater Ecology Evolution Behavior and Systematics 021101 geological & geomatics engineering 0105 earth and related environmental sciences |
| Zdroj: | Antarctic Science. 32:398-407 |
| ISSN: | 1365-2079 0954-1020 |
| DOI: | 10.1017/s0954102020000279 |
| Popis: | In this study, we aim to analyse the glacier dynamics of land-terminating glaciers in King George Island (Antarctica) between 1956 and 2018. Glacial fluctuations are estimated using space-borne remote sensing data (SPOT, Landsat, PlanetScope, Sentinel-1, Sentinel-2, WorldView-2 and TanDEM-X). The eastern sector of Warszawa Icefield witnessed continuous glacier retreat during 1979–2018 (surface loss of 30%). The decreases in the ice-covered areas of the Tower, Windy, Ecology, Baranowski and Sphinx glaciers were 70%, 31%, 25%, 25% and 21%, respectively, with their accumulation area ratios (AARs) exhibiting negative mass balances. The winter air temperature was cooler during the 1970s with warming trends in the 1980s and early 2000s followed by a cooling trend until the present day. However, the annual time series has shown high interannual variability in air temperature during these periods. We show that the AAR, dimensions, length, frontal elevation, maximum elevation, slope and changes in the terminus position influence the glacier response to climate change at various timescales. Furthermore, three geomorphic activity intensity zones and a complete paraglacial sequence are identified while contrasting the proglacial systems. Overall, subglacial deposits predominate and indicate that meltwater flows on the bed, producing wet-based thermal regimes. |
| Databáze: | OpenAIRE |
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