Chapter 5 - Tracing the deglaciation since the Last Glacial Maximum

The pre-last glacial maximum (LGM) Antarctic landscape with inherited preglacial topography (Sugden and Jamieson, 2018) was significantly overprinted by multiple ice advances and retreats driven by Milankovitch’s orbital forcing parameters during the Cenozoic (Hambrey and McKelvey, 2000, Naish et al., 2009, Davies et al., 2012b). This long geomorphological history has a fundamental effect on the subglacial topography (Fretwell et al., 2013) and on the ice-free landscapes located mostly in Antarctica’s outermost parts or in mountain ranges penetrating through the ice sheet. The recent calculations of rock outcrop areas for Antarctica (from its margin to 82°40′S) reveal much smaller values (21,745 km2) than the previous estimates (Burton-Johnson et al., 2016). This implies that exposed rocks form only ~ 0.2% of the total Antarctic continent area. However, these parts of Antarctic landscape underwent the most complex evolution since their deglaciation (i.e., in paraglacial phase) being shaped by marine, fluvial, eolian, slope, and last but not the least biological processes. Besides the present ice-free landscape could serve as an excellent playground to study processes and interactions, which will become much more common and widespread in Antarctica with the future deglaciation connected with ongoing global change