Impact of Antarctic Circumpolar Current Development on Late Paleogene Ocean Structure

  title={Impact of Antarctic Circumpolar Current Development on Late Paleogene Ocean Structure},
  author={Miriam E. Katz and Benjamin S. Cramer and J. R. Toggweiler and Gar Esmay and Chengjie Liu and Kenneth G. Miller and Yair Rosenthal and Bridget S. Wade and James Wright},
  pages={1076 - 1079}
The modern four-layered ocean structure developed during the early Oligocene, when Antarctica developed permanent ice cover. Global cooling and the development of continental-scale Antarctic glaciation occurred in the late middle Eocene to early Oligocene (~38 to 28 million years ago), accompanied by deep-ocean reorganization attributed to gradual Antarctic Circumpolar Current (ACC) development. Our benthic foraminiferal stable isotope comparisons show that a large δ13C offset developed between… 

Bipolar Atlantic deepwater circulation in the middle-late Eocene: Effects of Southern Ocean gateway openings

We present evidence for Antarctic Circumpolar Current (ACC)-like effects on Atlantic deepwater circulation beginning in the late-middle Eocene. Modern ocean circulation is characterized by a thermal

Antarctic climate, Southern Ocean circulation patterns, and deep-water formation during the Eocene

We assess early-to-middle Eocene seawater neodymium (Nd) isotope records from seven Southern Ocean deep-sea drill sites to evaluate the role of Southern Ocean circulation in long-term Cenozoic

Transient temperature asymmetry between hemispheres in the Palaeogene Atlantic Ocean

During the Late Palaeogene between ~40 and 23 million years ago (Ma), Earth transitioned from a warm non-glaciated climate state and developed large dynamic ice sheets on Antarctica. This transition

Antarctic glaciation caused ocean circulation changes at the Eocene–Oligocene transition

It is found that growth of the Antarctic ice sheet caused enhanced northward transport of Antarctic intermediate water and invigorated the formation of Antarctic bottom water, fundamentally reorganizing ocean circulation, whereas gateway openings had much less impact on ocean thermal stratification and circulation.

Sedimentological and oceanographic change in the Northwest Atlantic Ocean across the Eocene Oligocene Transition

The Eocene-Oligocene Transition (EOT) marks the most pivotal interval in Earth’s Cenozoic transition from warm, relatively ice-free ‘greenhouse’ conditions to a cooler ‘icehouse’ climate. The EOT saw

Late Eocene onset of the Proto-Antarctic Circumpolar Current

New seismic evidence of widespread Late Eocene to Oligocene marine diagenetic chert in sedimentary drift deposits east of New Zealand indicating prolonged periods of blooms of siliceous microorganisms starting ~36 million years ago reflects the initiation of the arrival and upwelling of northern-sourced, nutrient-rich deep equatorial Pacific waters at the high latitudes of the South Pacific.

Onset of Antarctic Circumpolar Current 30 million years ago as Tasmanian Gateway aligned with westerlies

Recon reconstructions of ocean circulation show that massive reorganization and homogenization of Southern Ocean water masses coincided with migration of the northern margin of the Tasmanian Gateway into the mid-latitude westerly wind band, which is reconstructed at 64° S, near to the northernmargin.

Southern Ocean warming and Wilkes Land ice sheet retreat during the mid-Miocene

It is suggested that the mid-Miocene latitudinal temperature gradient across the Southern Ocean never resembled that of the present day and that the East Antarctic subglacial basins were highly sensitive to ocean warming.



Late Oligocene initiation of the Antarctic Circumpolar Current: evidence from the South Pacific

The Antarctic Circumpolar Current (ACC) is a key feature of the Southern Ocean. Its development may have helped cool Antarctica and initiate Southern Hemisphere glaciation. The deep circulation of

Effect of the formation of the Isthmus of Panama on Atlantic Ocean thermohaline circulation

The Late Cenozoic closure of the seaway between the North andSouth American continents is thought to have caused extensive changes in ocean circulation and Northern Hemisphere climate. But the timing

Oligocene deep water export from the North Atlantic and the development of the Antarctic Circumpolar Current examined with neodymium isotopes

[1] Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene to Miocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in

Early Oligocene Onset of Deep-Water Production in the North Atlantic

The flow of deep-water masses is a key component of heat transport in the modern climate system, yet the role of deep-ocean heat transport during periods of extreme warmth is poorly understood. The

Cooling and ice growth across the Eocene-Oligocene transition

The Eocene-Oligocene (E-O) climate transition (ca. 34 Ma) marks a period of Antarctic ice growth and a major step from early Cenozoic greenhouse conditions toward today's glaciated climate state. The

A scenario of Mesozoic-Cenozoic ocean circulation over the Blake Plateau and its environs

After the continental breakup of North America, Africa, and Europe, a sluggish, wind-driven circulation gyre probably formed in the juvenile North Atlantic basin. Surface flow in the western Atlantic

Drake Passage and Cenozoic climate: An open and shut case?

Drake Passage opening has often been viewed as a single, discrete event, possibly associated with abrupt changes in global circulation and climate at or near the Eocene‐Oligocene boundary. A new