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

The continental slope seaward of the Totten Glacier and Sabrina Coast displays a suite of submarine canyons separated by ridges. The ridges show a range of morphological features that indicate they form by accretion of pelagic and hemipelagic sediment which can be remobilised by mass movement. The study area can be divided into two areas with distinct geomorphological features. Canyons in the eastern part of the study area have concave thalwegs and are linked to the shelf edge and upper slope and show signs of erosion and deposition along their beds suggesting cycles of activity controlled by climate cycles. The major canyon in the western part of the area has a convex thalweg. It is likely fed predominantly by mass movement from the flanks of the adjacent ridges with less input sediment from the shelf edge. The ridges between canyons in the Eastern part of the study area are asymmetric with crests close to the west bank of adjacent canyons and are mostly formed by westward advection of fine sediment lofted from turbidity currents and deposition of pelagic sediment. The ridges in the western part of the study area are more likely fully contourites, formed by accretion of suspended sediment with their associated canyons fed by flows derived predominantly from slumping on the adjacent ridge flanks. Canyons and ridges in the eastern part of the study area lie to the east of the Totten Glacier and are seaward of small ice drainage basins feeding the Moscow University Ice Shelf. Ridges and canyons in the western part of area formed from sediment transported along the margin and from detritus originating from the Totten Glacier. Higher sediment supply produced larger, shallower ridges that interact with ocean currents and coincide with a long-lived depocenter. The overall geomorphology of the Sabrina Coast slope is part of a continuum of mixed contourite-turbidite systems identified on the Antarctic margin. These ridges are thus prime locations to sample for sedimentary records of the Totten Glacier’s interaction with the adjacent ocean. Citation: E. O'Brien, A.L. Post, S. Edwards, T. Martin, A. Caburlotto, F. Donda, G. Leitchenkov, R. Romeo, M. Duffy, D. Evangelinos, L. Holder, A. Leventer, A. López-Quirós, B.N. Opdyke, L.K. Armand, Continental slope and rise geomorphology seaward of the Totten Glacier, East Antarctica (112°E-122°E), Marine Geology, Volume 427, 2020, 106221, ISSN 0025-3227, https://doi.org/10.1016/j.margeo.2020.1062