Debris-covered glaciers on Deception Island (Antarctica) as analogues for possible glaciers on the lower northwest flank of Hecates Tholus volcano, Mars

Deception Island, an active volcano located in the South Shetland Islands (Antarctica, 62°58′37”S, 60°39′00”W), exhibits an annular morphology approximately 12 km in diameter and a maximum elevation close to 540 m. A significant portion of its surface is covered by glaciers flowing from the ice cap perched on the island's elevated caldera rim and adjacent slopes, in places descending all the way to the coastline. Volcanic eruptions (1960s and 1970s) resulted in the deposition of a layer of pyroclastic material that partially covers these glaciers, hindering direct observation of the ice, although glacial landforms remain clearly recognizable. These conditions make Deception Island a suitable terrestrial analogue for the lower northwest flank of Hecates Tholus volcano (Mars), where ice is not exposed at the surface in orbital imagery but is inferred to occur beneath a volcaniclastic/debris mantle, and where similar volcanoclastic processes have occurred along Martian geological time. In this study, we qualitatively analyze and compare a range of geomorphological features identified in both study sites (Deception Island volcano, Antarctica, and the lower northwest flank of Hecates Tholus, Mars), including crevasses, bergschrunds, moraines, erratic boulders, depressions, glacier fronts, and ridges, among others. This qualitative comparison of the morphology and distribution of these features in Hecates Tholus supports the hypothesis regarding the existence of remnant glaciers currently buried beneath debris, pyroclastic deposits, and surface dust, a finding consistent with previous interpretations. Finally, we highlight the potential of Deception Island as an accessible and environmentally extreme analogue site for future investigations into Martian glacier dynamics.