Paleogene opening of Drake Passage

Livermore, Roy; Nankivell, Adrian P.; Eagles, Graeme; Morris, Peter

doi:10.1016/j.epsl.2005.03.027

Cited by 305 publications

(232 citation statements)

References 31 publications

Supporting

Mentioning

219

Contrasting

Unclassified

Order By: Relevance

“…It is likely that the thermal difference between the low-and high-latitude austral surface waters of the Atlantic Ocean fueled a meridional overturning circulation before the establishment of a true thermohaline circulation after the EOT (13). Considering surface and deep ocean circulation upheaval together, the timing of such profound reorganization of oceanic currents, which began between 41 Ma and 38 Ma, is compatible with the opening of the Drake Passage (44)(45)(46). Neodymium isotope data further confirm the influx of SW Pacific surface waters through this newly opened seaway from 41 Ma onward (47).…”

Section: Discussion Andmentioning

confidence: 77%

Equatorial heat accumulation as a long-term trigger of permanent Antarctic ice sheets during the Cenozoic

Tremblin

Hermoso

Minoletti

2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Growth of the first permanent Antarctic ice sheets at the Eocene−Oligocene Transition (EOT), ∼33.7 million years ago, indicates a major climate shift within long-term Cenozoic cooling. The driving mechanisms that set the stage for this glaciation event are not well constrained, however, owing to large uncertainties in temperature reconstructions during the Eocene, especially at lower latitudes. To address this deficiency, we used recent developments in coccolith biogeochemistry to reconstruct equatorial Atlantic sea surface temperature (SST) and atmospheric pCO 2 values from pelagic sequences preceding and spanning the EOT. We found significantly more variability in equatorial SSTs than previously reported, with pronounced cooling from the Early to Middle Eocene and subsequent warming during the Late Eocene. Thus, we show that the Antarctic glaciation at the Eocene−Oligocene boundary was preceded by a period of heat accumulation in the low latitudes, likely focused in a progressively contracting South Atlantic gyre, which contributed to cooling high-latitude austral regions. This prominent redistribution of heat corresponds to the emplacement of a strong meridional temperature gradient that typifies icehouse climate conditions. Our equatorial coccolith-derived geochemical record thus highlights an important period of global climatic and oceanic upheaval, which began 4 million years before the EOT and, superimposed on a longterm pCO 2 decline, drove the Earth system toward a glacial tipping point in the Cenozoic. . These records exhibit rather conflicting proxy data for the TDP and overall long-term cooling for the Atlantic sites 925 and 929. There is, however, no clear and significant cooling trend from the Early to Middle Eocene that indicates the termination of the Early Eocene Climatic Optimum (Fig. 1A). Furthermore, recent quality-checked SSTs for ODP 925 and 929 sites using the Ring Index indicate relatively similar temperatures between the Late Eocene and the Early Oligocene (5). In contrast, high-latitude sites are consistent in demonstrating appreciable cooling of austral subpolar regions during much of the Eocene (3,4,(6)(7)(8). This apparent lack of substantial temperature change in the intertropical belt during the Eocene and across the EOT remains an enigmatic feature that complicates our understanding of the interplay between seawater temperatures at a global scale, pCO 2 , and changes in global ocean circulations in the context of new Southern Ocean gateways (9-14). The paucity of low-latitude data, especially in the Pacific Ocean, prevents the reconstruction of the latitudinal temperature gradient, much needed for the successful modeling of processes that drove the greenhouse to icehouse transition (10, 15, 16).As an alternative to the relatively poor preservation of the foraminifera and issues with the calibration of organic-based proxies (1, 5, 17), this study exploits the coccoliths as a source of paleoclimatic information. Coccolithophores, single-celled phytoplankton algae, are a key componen...

show abstract

Section: Discussion Andmentioning

confidence: 77%

Equatorial heat accumulation as a long-term trigger of permanent Antarctic ice sheets during the Cenozoic

Tremblin

Hermoso

Minoletti

2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Incipient opening of the Drake Passage occurred around 41 Ma (Scher and Martin, 2006), and its deepening allowed for initiation of the ACC. There is debate as to whether the ACC was fully established either in the Early Oligocene, between 34 and 30 Ma (Livermore et al, 2005) or in the latest Oligocene, at about 24 Ma (Pfuhl and McCave, 2005;Lyle et al, 2007). In any case, in the Early Miocene the ACC was active, in analogy to the present-day situation, and correspondingly extensive ice sheets developed over Antarctica.…”

Section: Climate Paleoceanography and Tectonicsmentioning

confidence: 99%

Early Miocene subtropical water temperatures in the southeast Pacific

Nielsen

Glodny

2009

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

Cenozoic climate of western South America is strongly controlled by features like Andean uplift and the Humboldt Current. The first strontium isotope age data from central and southern Chile provide a latest Oligocene to late early Miocene age for classic warm-water mollusk faunas reaching as far south as 45°S.Comparison with the biogeography of congeneric living species indicates that sea surface temperatures off central and southern Chile during that time were at least 5°C higher than today; i.e., minimum annual mean sea surface temperatures for Darwin's Navidad fauna at 34°S are estimated as 20°C. As expected, the number of tropical taxa decreases towards the south but several are still present as far south as 45°S. The ages scatter relatively broadly between ~24 and ~16 Ma, partly even within individual localities. Shallow water and deeper water faunas are revealed to have similar ages. When considered in light of convincing micropaleontological evidence for late Miocene to early Pliocene depositional ages, the Srisotope data support a hypothesis that the mollusk fauna is reworked.

show abstract

“…The Eocene-Oligocene transition at~33 Ma signifies a period of several major changes: Antarctica's climate changed from warm and relatively ice-sheet free to cold and ice-covered, as temperatures decreased by about 4°C; pCO 2 declined rapidly from 1750 to 700 ppm and orbital cycles changed (Barker, 2001;Zachos et al, 2001;DeConto and Pollard, 2003;Barker and Thomas, 2004;Coxall et al, 2005;Livermore et al, 2005;Pollard and DeConto, 2009); the Antarctic Circumpolar Current (ACC) developed Gahagan, 1998, 2003;Miller et al, 2008) as the Weddell Sea and Drake Passage opened and western Scotia Sea started to open Ghidella et al, 2002;König and Jokat, 2006;Maldonado et al, 2006); ephemeral ice sheets formed the initial East Antarctic Ice Sheet (EAIS) and West Antarctic Ice Sheet (WAIS) on higher elevations Barker et al, 1988;Miller et al, 1990;Oszko, 1997;Barker, 2001) as well as small ice-caps on the northern Antarctic Peninsula Smith and Anderson, 2010;.…”

Section: Tectonic Palaeoceanographic and Palaeoclimate Settingmentioning

confidence: 99%