Fig. 2: CHIRP (Compressed High Intensity Radar Pulse) profiles collected off Totten Glacier.
From: Footprint of sustained poleward warm water flow within East Antarctic submarine canyons
a Part of the sub-bottom CHIRP profile 110 collected on the Sabrina Coast continental rise and seismostratigraphic interpretation highlighting the relationship between the present day Maadjit canyon-levee system, represented by the elongated feature visible on the morpho-bathymetry map (d) and the sediment drift deposited on its eastern flank. The sediment drift appears to be coeval or even younger than the levee deposit, and shows an eastward crest migration; (b) part of the sub-bottom CHIRP profile 72 collected on the Sabrina Coast continental rise and seismostratigraphic interpretation. The sediment drift is thicker than to the south (80 m vs 50 m; the time-depth conversion is shown in the “Methods” section). In this area, the present-day Maadjit canyon is lacking the related eastern levee, possibly since downslope flows progressively lose competence as they reach deeper areas. To the west, abrupt reflection truncations suggest the occurrence of a slide scar (see also d). c Multichannel seismic profile RAE5108 showing the overall “paleo configuration” of the Sabrina Coast continental rise. Here sediment-laden downslope gravity currents were deviated to the west by the combined effect of the slope currents and the Coriolis force when a highly dynamic ice sheet, reaching the continental margin, led to turbidite flows across the continental slope (modified from43,51). d Location map of the sub-bottom CHIRP and multichannel seismic profiles; white dots indicate the position of Conductivity-Temperature-Depth (CTD) vertical profiles gathered in January–February 2017; the location of sediment cores PC05 and PC08 coincides with CTD09 and CTD022 stations, respectively; the encircled red star shows the location of the sediment drift shown in the Supplementary Information; light orange arrows represent time-mean (2011–2018) surface velocity vectors from ref. 20. The location of the slide scar recognizable on the CHIRP profile shown in (b) is also marked. The white ellipses outline the inferred shape of the sediment drifts shown in (a, b).
