Initiation of the West Antarctic ice sheet and estimates of total Antarctic ice volume in the earliest Oligocene.

• Published in: Geophysical Research Letters
• Main Authors: Wilson, D.S., Pollard, D., DeConto, R., Jamieson, S.S.R., Luyendyk, B.P.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2013
• Subjects: Antarctic; Ice sheet; Oligocene; East Antarctica; The Antarctic; West Antarctic Ice Sheet; Antarc*; Antarctica; Ice Sheet
• Online Access: http://dro.dur.ac.uk/11390/; http://dro.dur.ac.uk/11390/1/11390.pdf; https://doi.org/10.1002/grl.50797

Reconstructions of Antarctic paleotopography for the late Eocene suggest that glacial erosion and thermal subsidence have lowered West Antarctic elevations considerably since then, with Antarctic land area having decreased ~20%. A new climate-ice sheet model based on these reconstructions shows that the West Antarctic Ice Sheet first formed at the Eocene-Oligocene transition (33.8–33.5 Ma, E-O) in concert with the continental-scale expansion of the East Antarctica Ice Sheet and that the total volume of East and West Antarctic ice (33.4–35.9 × 106 km3) was >1.4 times greater than previously assumed. This larger modeled ice volume is consistent with a modest cooling of 1–2°C in the deep ocean during the E-O transition, lower than other estimates of ~3°C cooling, and suggests the possibility of substantial ice in the Antarctic interior before the Eocene-Oligocene boundary.