Fig. 7: Conceptual model for the upwelling of deep water onto the ASE shelf in EOT. | Communications Earth & Environment

Fig. 7: Conceptual model for the upwelling of deep water onto the ASE shelf in EOT.

From: Deep water inflow slowed offshore expansion of the West Antarctic Ice Sheet at the Eocene-Oligocene transition

Fig. 7

a The minimum reconstruction of the palaeotopography/palaeobathymetry for 34 Ma shows a trough mouth or canyon in the shelf break22,41,82, which enables the intrusion of deep water (rose arrows) onto the shelf as the result of southward Ekman transport (white E, white arrow) within the easterly winds (eW). The southward flow of deep water is steered by the higher topography on the eastern ASE shelf and shapes the sediment drift (red lines). b Later in the Oligocene, increasing global cooling will have relocated the wind system (eW) northwards and influenced the intensity of upwelling. Deep water (purple arrows) now can only upwell into the outer trough and is recirculated back into the deeper ocean. This may have ended the formation of the observed sediment drift plastered against seismic horizon ASS-u2 below the eastern flank of the present-day PIT. eW= easterly winds, E, S, W = East, South, West.

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