Continental slope and rise geomorphology seaward of the Totten Glacier, East Antarctica (112°E-122°E)

Scratching the Surface: A Marine Sediment Provenance Record From the Continental Slope of Central Wilkes Land, East Antarctica

“…The interpreted extension of the Banzare Province beneath multiple subglacial catchments east of the Totten catchment (Maritati et al., 2019) suggests likely detrital contributions from the Moscow University, Thompson, and Holmes glaciers (Figure 9). This idea is supported by recent interpretations of the continental slope morphology that suggest that the contourite ridge from which KC14 was recovered is fed not only by detritus from the Totten Glacier, but also by fine sediment plumes transported westward across the slope by the Antarctic Coastal Current (O'Brien et al., 2020). With an ice sheet slightly advanced relative to modern grounding line, the ice sheet model of Aitken et al.…”

“…This process explains the higher calculated “IBRD” flux during the glacial (Figure 3), when iceberg calving would have been infrequent and the quantity of IBRD is expected to be low (Bertram et al., 2018; Wilson et al., 2018). A mixture of this coarse debris and fallout of finer sediment from suspension in sediment‐laden plumes likely contributed to the maintenance of the large contourite ridge where KC14 is located (O'Brien et al., 2020; Post et al., 2020). The similarity in age distribution between intervals 1 and 4 suggests that the sediment reworked in debris flows as the ice sheet advanced was initially deposited during past warmer climate periods, when the position of the retreated ice sheet margin and the provenance of continentally derived detritus was similar to that of the present day.…”

“…(2020) suggested that the proximal Totten Glacier likely supplies a significant component of detritus to the slope in sediment‐laden meltwater fluxes, maintaining these submarine landforms. Gullies developed in the east of the study region, where turbidite flows and meltwater fed by major glacial systems scoured into the seabed (Donda et al., 2020; O'Brien et al., 2020; Post et al., 2020).…”

Controls Since the mid‐Pleistocene Transition on Sedimentation and Primary Productivity Downslope of Totten Glacier, East Antarctica

“…Along the upper slope, gullies with low‐slope angles trigger sediment failure, resulting in sediment gravity flows that are funneled through the canyon network seen next to Site C012 (Post et al, 2020). The fine fraction of the flow settles slowly and is lofted to the west of canyon systems by along‐slope currents such as the westward flowing ASC and AABW (O'Brien et al, 2020). The increase in terrigenous sedimentation at the study site during glacial periods most likely relates to more frequent occurrence of sediment gravity flows from sediment loading along the shelf break.…”

“…Downslope sediment gravity flows and reworking from along‐slope currents have been a consistent feature in molding channel‐levee systems around the Antarctic margin during cooler periods (Escutia et al, 2002). In the eastern region, seaward of the Moscow University Ice Shelf, sediment routing is focused by the gullies along the shelf break (Post et al, 2020) and funneled into the Maadjit and Manang canyons whereby the fine fraction is lofted across the ridgeline to Site C012 (Close, 2010; O'Brien et al, 2020). This depositional system is thought to be very similar to Site U1361 and others along canyon‐ridge networks off Wilkes Land (Escutia et al, 2003, 2011; Jimenez‐Espejo et al, 2020; Presti et al, 2011).…”