Eocene circulation of the Southern Ocean: Was Antarctica kept warm by subtropical waters?

2004/12/01 by Matthew Huber, Henk Brinkhuis, Catherine E Stickley +5 · 12 citations
Earth and Planetary Sciences · #Geology and Paleoclimatology Research #Evolution and Paleontology Studies #Paleontology and Stratigraphy of Fossils

paper · doi:10.1029/2004pa001014

openalex publication_date 2004/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Near the Eocene's close (∼34 million years ago), the climate system underwent one of the largest shifts in Earth's history: Antarctic terrestrial ice sheets suddenly grew and ocean productivity patterns changed. Previous studies conjectured that poleward penetration of warm, subtropical currents, the East Australian Current (EAC) in particular, caused Eocene Antarctic warmth. Late Eocene opening of an ocean gateway between Australia and Antarctica was conjectured to have disrupted the EAC, cooled Antarctica, and allowed ice sheets to develop. Here we reconstruct Eocene paleoceanographic circulation in the Tasmanian region, using (1) biogeographical distributions of phytoplankton, including data from recently drilled Ocean Drilling Program Leg 189 sites and (2) fully coupled climate model simulations. We find that the EAC did not penetrate to high latitudes and ocean heat transport in the region was not greater than modern. Our results do not support changes in “thermal isolation” as the primary driver of the Eocene‐Oligocene climatic transition.

Citations

• Cooler winters as a possible cause of mass extinctions at the Eocene/Oligocene boundary
• Atmospheric carbon dioxide concentrations over the past 60 million years
• Timing and nature of the deepening of the Tasmanian Gateway
• Significant Southern Ocean warming event in the late middle Eocene
• Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2
• High‐resolution (104 years) deep‐sea foraminiferal stable isotope records of the Eocene‐Oligocene climate transition
• Atmospheric carbon dioxide and early Eocene climate: A general circulation modeling sensitivity study
• Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present

Cited by

• Eocene cooling linked to early flow across the Tasmanian Gateway
• The ocean circulation in the southern hemisphere and its climatic impacts in the Eocene
• Synchronous tropical and polar temperature evolution in the Eocene
• Chapter 8 From Greenhouse to Icehouse – The Eocene/Oligocene in Antarctica
• Pacific Ocean and Cenozoic evolution of climate
• Late Oligocene initiation of the Antarctic Circumpolar Current: Evidence from the South Pacific
• The effect of gateways on ocean circulation patterns in the Cenozoic
• Chapter 9 The Oligocene–Miocene Boundary – Antarctic Climate Response to Orbital Forcing
• Using reverse logistics for failed spare parts : a new opportunity for Vanderlande Industries
• Resolving a late Oligocene conundrum: Deep-sea warming and Antarctic glaciation
• The formation of the oceanic temperate forests of New Zealand
• Eocene [wikipedia]