Wilkes Subglacial Basin covers an area of 400,000 km2, and stores a volume of ice equivalent to approximately 3 to 4 metres of sea-level rise. Both model simulations and observational evidence from sediment cores indicate that the basin is susceptible to significant instability, and has seen extensive deglaciation and retreat in periods over the Pleistocene and Pliocene. The basin is flanked by two ice cores: EPICA Dome C Ice Core, situated closer to the South Pole and with a record dating back to approximately 800 ka, and Talos Dome Ice Core, situated closer to the coast and extending back to approximately 350 ka. Englacial stratigraphy that is imaged by radio-echo sounding can be dated at intersections with deep ice cores, and therefore provide observational evidence of palaeo-behaviour of ice sheets beyond the point-based measurements that are generated by ice cores. To date, the englacial stratigraphy between the two ice cores has not been comprehensively investigated. Here, we analyse the englacial stratigraphy through an airborne radio-echo sounding dataset of 61,000 km of radar profiles, jointly acquired in 2005-2006 by the British Antarctic Survey (BAS) and the Italian Programma Nazionale di Ricerche in Antartide (the WISE-ISODYN survey). The data were acquired with the BAS Polarimetric Survey Instrument (PASIN) with a central frequency of 150 MHz. We have traced multiple englacial layers between Dome C and Talos Dome Ice Cores, with at least one layer of age 38 ka directly connecting the 1,100 km distance between the two ice cores. Overall, the architecture of englacial layers spanning between the two ice cores confirms that ice has pervasively covered the upstream region of Wilkes Subglacial Basin, 250 km upstream from the present grounding line, since at least 60 ka. Future work will be conducted to extend these layers closer towards the grounding line of Wilkes Subglacial Basin.
Stability of Wilkes Subglacial Basin since before the last glacial maximum signalled by englacial stratigraphy connecting Dome C and Talos Dome Ice Cores
Fausto Ferraccioli;Egidio Armadillo
2025-01-01
Abstract
Wilkes Subglacial Basin covers an area of 400,000 km2, and stores a volume of ice equivalent to approximately 3 to 4 metres of sea-level rise. Both model simulations and observational evidence from sediment cores indicate that the basin is susceptible to significant instability, and has seen extensive deglaciation and retreat in periods over the Pleistocene and Pliocene. The basin is flanked by two ice cores: EPICA Dome C Ice Core, situated closer to the South Pole and with a record dating back to approximately 800 ka, and Talos Dome Ice Core, situated closer to the coast and extending back to approximately 350 ka. Englacial stratigraphy that is imaged by radio-echo sounding can be dated at intersections with deep ice cores, and therefore provide observational evidence of palaeo-behaviour of ice sheets beyond the point-based measurements that are generated by ice cores. To date, the englacial stratigraphy between the two ice cores has not been comprehensively investigated. Here, we analyse the englacial stratigraphy through an airborne radio-echo sounding dataset of 61,000 km of radar profiles, jointly acquired in 2005-2006 by the British Antarctic Survey (BAS) and the Italian Programma Nazionale di Ricerche in Antartide (the WISE-ISODYN survey). The data were acquired with the BAS Polarimetric Survey Instrument (PASIN) with a central frequency of 150 MHz. We have traced multiple englacial layers between Dome C and Talos Dome Ice Cores, with at least one layer of age 38 ka directly connecting the 1,100 km distance between the two ice cores. Overall, the architecture of englacial layers spanning between the two ice cores confirms that ice has pervasively covered the upstream region of Wilkes Subglacial Basin, 250 km upstream from the present grounding line, since at least 60 ka. Future work will be conducted to extend these layers closer towards the grounding line of Wilkes Subglacial Basin.
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