Oceanography The Official Magazine of
The Oceanography Society
Volume 25 Issue 03

View Issue TOC
Volume 25, No. 3
Pages 106 - 117

Southern Exposure: New Paleoclimate Insights From Southern Ocean and Antarctic Margin Sediments

Amelia E. Shevenell Steven M. Bohaty
Article Abstract

Much of what is known about the evolution of Antarctica’s cryosphere in the geologic past is derived from ice-distal deep-sea sedimentary records. Recent advances in drilling technology and climate proxy methods have made it possible to retrieve and interpret high-quality ice-proximal sedimentary sequences from Antarctica’s margins and the Southern Ocean. These records contain a wealth of information about the individual histories of the East and West Antarctic Ice Sheets and associated temperature change in the circum-Antarctic seas. Emerging studies of Antarctic drill cores provide evidence of dynamic climate variability on both short and long timescales over the past 20 million years. This geologic information is critical for testing and improving computer model simulations used to predict future environmental change in the polar regions. Identifying the mechanistic links between past Antarctic ice-volume fluctuations and oceanographic change is necessary for understanding Earth’s long-term climate evolution. While recent successes highlight the value of ice-proximal records, additional scientific drilling and climate proxy development are required to improve current knowledge of Antarctica’s complex paleoenvironmental history.

Citation

Shevenell, A.E., and S.M. Bohaty. 2012. Southern exposure: New paleoclimate insights from Southern Ocean and Antarctic margin sediments. Oceanography 25(3):106–117, https://doi.org/10.5670/oceanog.2012.82.

References

Anderson, J.B., S.S. Shipp, A.L. Lowe, J.S. Wellner, and A.B. Mosola. 2002. The Antarctic Ice Sheet during the Last Glacial Maximum and its subsequent retreat history: A review. Quaternary Science Reviews 21:49–70, https://doi.org/10.1016/S0277-3791(01)00083-X.

Anderson, J.B., S. Warny, R.A. Askin, J.S. Wellner, S. Bohaty, A.E. Kirshner, D.N. Livsey, A.R. Simms, T.R. Smith, W. Ehrmann, and others. 2011. Progressive Cenozoic cooling and the demise of Antarctica’s last refugium. Proceedings of the National Academy of Sciences of the United States of America 108:11,256–11,360, https://doi.org/10.1073/pnas.1014885108.

Anderson, R.F., S. Ali, L.I. Bradtmiller, S.H.H. Nielsen, M.Q. Fleisher, B.E. Anderson, and L.H. Burkle. 2009. Wind-driven upwelling in the Southern Ocean and the atmospheric rise in CO2. Science 323:1,443–1,448, https://doi.org/10.1126/science.1167441.

Barrett, P.J., P.-N. Webb, D. Fűtterer, C. Ghezzo, M.R.A. Thomson, A.R. Pyne, and F.R. Rack. 2007. Future Antarctic geological drilling: Discussion paper on ANDRILL and beyond. Extended Abstract 139 in Antarctica: A Keystone in a Changing World–Online Proceedings of the 10th International Symposium on Antarctic Sciences. A.K. Cooper, C.R. Raymond, and the 10th ISAES Editorial Team, USGS Open-File Report 2007-1047.

Belt, S.T., G. Masse, S.J. Rowland, M. Poulin, C. Michel, and B. LeBlanc. 2007. A novel chemical fossil of palaeo sea ice: IP25. Organic Geochemistry 38:16–27, https://doi.org/10.1016/j.orggeochem.2006.09.013.

Bentley, M.J., D.A. Hodgson, J.A. Smith, C. Ó Cofaigh, E.W. Domack, R.D. Larter, S.J. Roberts, S. Brachfeld, A. Leventer, C. Hjort, and others. 2009. Mechanisms of Holocene palaeoenvironmental change in the Antarctic Peninsula region. The Holocene 19:51–69, https://doi.org/10.1177/0959683608096603.

Bitz, C.M., K.M. Shell, P.R. Gent, D.A. Bailey, G. Danabasoglu, K.C. Armour, M.M. Holland, and J.T. Kiehl. 2012. Climate sensitivity of the Community Climate System Model, Version 4. Journal of Climate 25:3,053–3,070, https://doi.org/10.1175/JCLI-D-11-00290.1.

Burke, A., and L.F. Robinson. 2012. The Southern Ocean’s role in carbon exchange during the last deglaciation. Science 335:557–561, https://doi.org/10.1126/science.1208163.

Church, M.J., E.F. DeLong, H.W. Ducklow, M.B. Karner, C.M. Preston, and D.M. Karl. 2003. Abundance and distribution of planktonic Archaea and Bacteria in the waters west of the Antarctic Peninsula. Limnology and Oceanography 48:1,893–1,902, https://doi.org/10.4319/lo.2003.48.5.1893.

Cramer, B.S., K.G. Miller, P.J. Barrett, and J.D. Wright. 2011. Late Cretaceous–Neogene trends in deep ocean temperature and continental ice volume: Reconciling records of benthic foraminiferal geochemistry (δ18O and Mg/Ca) with sea level history. Journal of Geophysical Research-Oceans 116, C12023, https://doi.org/10.1029/2011JC007255.

Cramer, B.S., J.R. Toggweiler, J.D. Wright, M.E. Katz, and K.G. Miller. 2009. Ocean overturning since the Late Cretaceous: Inferences from a new benthic foraminiferal isotope compilation. Paleoceanography 24, PA4216, https://doi.org/10.1029/2008PA001683.

DeConto, R., D. Pollard, P. Wilson, H. Pälike, C. Lear, and M. Pagani. 2008. Thresholds of Cenozoic bipolar glaciation. Nature 455:652–658, https://doi.org/10.1038/nature07337.

DeConto, R.M., and D. Pollard. 2003. Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2. Nature 421:245–259, https://doi.org/10.1038/nature01290.

Denton, G.H., R.F. Anderson, J.R. Toggweiler, R.L. Edwards, J.M. Schaefer, and A.E. Putnam. 2010. The last glacial termination. Science 328:1,652–1,656, https://doi.org/10.1126/science.1184119.

Domack, E., A. Leventer, R. Dunbar, F. Taylor, S. Brachfeld, C. Sjunneskog, and the ODP Leg 178 Scientific Party. 2001. Chronology of the Palmer Deep site, Antarctic Peninsula: A Holocene palaeoenvironmental reference for the circum-Antarctic. Holocene 11:1–9, https://doi.org/10.1191/095968301673881493.

Escutia, C., M.A. Bárcena, R.G. Lucchi, O. Romero, A.M. Ballegeer, J.J. Gonzalez, and D.M. Harwood. 2009. Circum-Antarctic warming events between 4 and 3.5 Ma recorded in marine sediments from the Prydz Bay (ODP Leg 188) and the Antarctic Peninsula (ODP Leg 178) margins. Global and Planetary Change 69:170–184, https://doi.org/10.1016/j.gloplacha.2009.09.003.

Escutia, C., H. Brinkhuis, A. Klaus, and the Expedition 318 Scientists. 2011. Wilkes Land glacial history. Proceedings of the Integrated Ocean Drilling Program 318. Integrated Ocean Drilling Program Management International, Inc., https://doi.org/10.2204/iodp.proc.318.2011.

Feakins, S.J., S. Warny, S., and J.E. Lee. 2012. Hydrologic cycling over Antarctica during the middle Miocene warming. Nature Geoscience 5:557–560, https://doi.org/10.1038/NGEO1498.

Flower, B.P. 1999. Palaeoclimatology: Warming without high CO2? Nature 399:313–314, https://doi.org/10.1038/20568.

Flower, B.P., and J.P. Kennett. 1994. The middle Miocene climate transition: East Antarctic ice sheet development, deep ocean circulation and global carbon cycling. Palaeogeography, Palaeoclimatology, Palaeoecology 108:537–555, https://doi.org/10.1016/0031-0182(94)90251-8.

Gille, S.T. 2002. Warming of the Southern Ocean since the 1950s. Science 295:1,275–1,277, https://doi.org/10.1126/science.1065863.
Harwood, D., F. Florindo, F. Talarico, and R. Levy, eds. 2008–2009. Studies from the ANDRILL, Southern McMurdo Sound Project, Antarctica. Initial Science Report on AND-2A. Terra Antarctica 15(1), 235 pp.

Hauptvogel, D.W., and S. Passchier. 2012. Early-Middle Miocene (17–14 Ma) Antarctic ice dynamics reconstructed from the heavy mineral provenance in the AND-2A drill core, Ross Sea, Antarctica. Global and Planetary Change 82–83:38–50, https://doi.org/10.1016/j.gloplacha.2011.11.003.

Hillenbrand, C.D., and W. Ehrmann. 2005. Late Neogene to Quaternary environmental changes in the Antarctic Peninsula region: Evidence from drift sediments. Global and Planetary Change 45:165–191, https://doi.org/10.1016/j.gloplacha.2004.09.006.

Hillenbrand, C.D., and D.K. Fütterer. 2001. Neogene to Quaternary deposition of opal on the continental rise west of the Antarctic Peninsula, ODP Leg 178, Sites 1095, 1096, and 1101. Pp. 1–33 in Proceedings of the Ocean Drilling Program Scientific Results, Vol. 178. P.F. Barker, A. Camerlenghi, G.D. Acton, and A.T.S. Ramsay, eds, https://doi.org/0.2973/odp.proc.sr.178.215.2001.

Holbourn, A., W. Kuhnt, M. Schulz, and H. Erlenkeuser. 2005. Impacts of orbital forcing and atmospheric carbon dioxide on Miocene ice-sheet expansion. Nature 438:483–487, https://doi.org/10.1038/nature04123.

IPCC (Intergovernmental Panel on Climate Change). 2007. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. S. Solomon, D.

Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. Miller, eds, Cambridge University Press, Cambridge, UK, and New York, 996 pp.

Ingólfsson, Ó., C. Hjort, P.A. Berkman, S. Bjorck, E. Colhoun, I.D. Goodwin, B. Hall, K. Hirakawa, M. Melles, P. Moller, and M.L. Prentice. 1998. Antarctic glacial history since the Last Glacial Maximum: An overview of the record on land. Antarctic Science 10:326–344.

Kennett, J.P. 1977. Cenozoic evolution of Antarctic glaciation, the circum-Antarctic Ocean, and their impact on global paleoceanography. Journal of Geophysical Research 82:3,843–3,860, https://doi.org/10.1029/JC082i027p03843.

Kim, J.-H., X. Crosta, V. Willmott, H. Renssen, J. Bonnin, P. Helmke, S. Schouten, and J.S. Sinninghe Damsté. 2012. Holocene subsurface temperature variability in the eastern Antarctic continental margin. Geophysical Research Letters 39, L06705, https://doi.org/10.1029/2012GL051157.

Kim J.-H., S. Schouten, E.C. Hopmans, B. Donner, and J.S. Damsté. 2008. Global sediment core-top calibration of the TEX86 paleothermometer in the ocean. Geochimica et Cosmochimica Acta 72:1,154–1,173, https://doi.org/10.1016/j.gca.2007.12.010.

Kominz, M.A., J.V. Browning, K.G. Miller, P.J. Sugarman, S. Mizintseva, and C.R. Scotese. 2008. Late Cretaceous to Miocene sea level estimates from the New Jersey and Delaware coastal plain coreholes: An error analysis. Basin Research 20:211–226.

Kurschner, W.M., Z. Kvacek, and D.L. Dilcher. 2008. The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of terrestrial ecosystems. Proceedings of the National Academy of Sciences of the United States of America 105:449–453, https://doi.org/10.1073/pnas.0708588105.

Lear, C.H., E.M. Mawbey, and Y. Rosenthal. 2010. Cenozoic benthic foraminiferal Mg/Ca and Li/Ca records: Toward unlocking temperatures and saturation states. Paleoceanography 25, PA4215, https://doi.org/10.1029/2009PA001880.

Leventer, A., E. Domack, R. Dunbar, J. Pike, C. Stickley, E. Maddison, S. Brachfeld, P. Manley, and C. McClennen. 2006. Marine sediment record from the East Antarctic margin reveals dynamics of ice sheet recession. GSA Today 16(12):4–10, https://doi.org/10.1130/GSAT01612A.1.

Lewis, A.R., D.R. Marchant, A.C. Ashworth, L. Hedenas, S.R. Hemming, J.V. Johnson, M.J. Leng, M.L. Machlus, A.E. Newton, J.I. Raine, and others. 2008. Mid-Miocene cooling and the extinction of tundra in continental Antarctica. Proceedings of the National Academy of Sciences of the United States of America 105:10,676–10,689, https://doi.org/10.1073/pnas.0802501105.

Lisiecki, L.E., and M.E. Raymo. 2005. A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records. Paleoceanography 20, PA1003, https://doi.org/10.1029/2004PA001071.

Luthi D., M. Le Floch, B. Bereiter, T. Blunier, J.-M. Barnola, U. Siegenthaler, D. Raynaud, J. Jouzel, H. Fischer, K. Kawamura, and T.F. Stocker. 2008. High-resolution carbon dioxide concentration record 650,000–800,000 years before present. Nature 453:379–382, https://doi.org/10.1038/nature06949.

Mackintosh, A., N. Golledge, E. Domack, R. Dunbar, A. Leventer, D. White, D. Pollard, R. DeConto, D. Fink, G. Gore, and C. Lavoie. 2011. Retreat of the East Antarctic ice sheet during the last glacial termination. Nature Geoscience 4:195–202, https://doi.org/10.1038/ngeo1061.

Majewski, W., and S.M. Bohaty. 2010. Surface-water cooling and salinity decrease during the Middle Miocene climate transition at Southern Ocean ODP Site 747 (Kerguelen Plateau). Marine Micropaleontology 74:1–14, https://doi.org/10.1016/j.marmicro.2009.10.002.

McKay R., T. Naish, L. Carter, C. Riesselman, R. Dunbar, C. Sjunneskog, D. Winter, F. Sangoirgi, C. Warren, M. Pagani, and others. 2012. Antarctic and Southern Ocean influences on Late Pliocene global cooling. Proceedings of the National Academy of Sciences of the United States of America 109:6,423–6,428, https://doi.org/10.1073/pnas.1112248109.

Meinshausen, M., S.J. Smith, K. Calvin, J.S. Daniel. M.L.T. Kainuma, J.-F. Lamarque, K. Matsumoto, S.A. Montzka, S.C.B. Raper, K. Riahi, and others. 2011. The RCP greenhouse gas concentrations and their extensions from 1765 to 2300. Climatic Change 109:213–241, https://doi.org/10.1007/s10584-011-0156-z.

Miller, K.G., R.G. Fairbanks, and G.S. Mountain. 1987. Tertiary oxygen isotope synthesis, sea-level history, and continental margin erosion. Paleoceanography 2:1–19, https://doi.org/10.1029/PA002i001p00001.

Miller, K.G., M.A. Kominz, J.V. Browning, J.D. Wright, G.S. Mountain, M.E. Katz, P.J. Sugarman, B.S. Cramer, N. Christie-Blick, and S.F. Pekar. 2005. The Phanerozoic record of global sea-level change. Science 310:1,293–1,298, https://doi.org/10.1126/science.1116412.

Miller, K.G., J.D. Wright, J.V. Browning, A. Kulpecz, M. Kominz, T.R. Naish, B.S. Cramer, Y. Rosenthal, W.R. Peltier, and S. Sosdian. 2012. High tide of the warming Pliocene: Implications of global sea level and Antarctic deglaciation. Geology 40:407–410, https://doi.org/10.1130/G32869.1.

Monnin, E., A. Indermuhle, A. Dallenbach, J. Fluckiger, B. Stauffer, T.F. Stocker, D. Raynaud, and J.-M. Barnola. 2001. Atmospheric CO2 concentration over the last glacial termination. Science 291:112–114, https://doi.org/10.1126/science.291.5501.112.

Naish, T.R., R.D. Powell, S.A. Henrys, G. Wilson, L.A. Krissek, F. Niessen, M. Pompilio, R. Scherer, F. Talarico, R. Levy, and A.R. Pyne. 2008. Late Cenozoic climate history of the Ross Embayment from the AND-1B drill hole: Culmination of three decades of Antarctic margin drilling. Pp. 71–82 in Antarctica: A Keystone in a Changing World. Proceedings of the 10th International Symposium on Antarctic Earth Sciences. A.K. Cooper, P.J. Barrett, H. Stagg, B. Storey, E. Stump, W. Wise, and the 10th ISAES editorial team, eds, The National Academies Press Washington, DC.

Naish, T., R.D. Powell, R.H. Levy, S. Henrys, L. Krissek, F. Niessen, M. Pompillo, R. Scherer, and G.S. Wilson. 2007. Synthesis of the Initial Scientific Results of the MIS Project, Victoria Land Basin, Antarctica. Terra Antarctica 14:317–333.

Naish, T., R. Powell, R. Levy, G. Wilson, R. Scherer, F. Talarico, L. Krissek, F. Niessen, M. Pompillo, T. Wilson, and others. 2009. Obliquity-paced Pliocene West Antarctic ice sheet oscillations. Nature 458:322–329, https://doi.org/10.1038/nature07867.

Pagani, M., M.A. Arthur, and K.H. Freeman. 1999. Miocene evolution of atmospheric carbon dioxide. Paleoceanography 14:273–292, https://doi.org/10.1029/1999PA900006.

Pagani, M., M. Huber, Z. Liu, S.M. Bohaty, J. Hendericks, W. Sijp, S. Krishnan, and R.M. DeConto. 2011. The role of carbon dioxide during the onset of Antarctic glaciation. Science 334:1,261–1,264, https://doi.org/10.1126/science.1203909.

Pagani, M., Z. Liu, J. LaRiviere, and A.C. Ravelo. 2010. High Earth-system climate sensitivity determined from Pliocene carbon dioxide concentrations. Nature Geoscience 3:27–30, https://doi.org/10.1038/ngeo724.

Pagani, M., J.C. Zachos, K.H. Freeman, B. Tipple, and S. Bohaty. 2005. Marked decline in atmospheric carbon dioxide concentrations during the Paleogene. Science 309:600–603, https://doi.org/10.1126/science.1110063.

Passchier, S. 2011. Linkages between East Antarctic Ice Sheet extent and Southern Ocean temperatures based on a Pliocene high-resolution record of ice-rafted debris off Prydz Bay, East Antarctica. Paleoceanography 26, PA4204, https://doi.org/10.1029/2010PA002061.

Pearson, P.N., G.L. Foster, and B.S. Wade. 2009. Atmospheric carbon dioxide through the Eocene-Oligocene climate transition. Nature 461:1,110–1,113, https://doi.org/10.1038/nature08447.

Pearson, P.N., and M.R. Palmer. 2000. Atmospheric carbon dioxide concentrations over the past 60 million years. Nature 406:695–699, https://doi.org/10.1038/35021000.

Pollard, D., and R. DeConto. 2009. Modelling West Antarctic ice sheet growth and collapse through the past five million years. Nature 458:320–323, https://doi.org/10.1038/nature07809.

Purkey, S.G., and G.C. Johnson. 2010. Warming of global abyssal and deep southern ocean waters between the 1990s and 2000s: Contributions to global heat and sea level rise budgets. Journal of Climate 23:6,336–6,351, https://doi.org/10.1175/2010JCLI3682.1.

Raymo, M.E., J.X. Mitrovica, M.J. O’Leary, R.M. DeConto, and P.J. Hearty. 2011. Departures from eustasy in Pliocene sea-level records. Nature Geoscience 4:328–332, https://doi.org/10.1038/ngeo1118.

Raymo, M.E., L.E. Lisiecki, and N. Nisancioglu. 2006. Plio-Pleistocene ice volume, Antarctic climate, and the global δ18O record. Science 313:492–495, https://doi.org/10.1126/science.1123296.

Rignot, E., and S.S. Jacobs. 2002. Rapid bottom melting widespread near Antarctic ice sheet grounding lines. Science 296:2,020–2,023, https://doi.org/10.1126/science.1070942.

Sandroni, S., and F.M. Talarico. 2011. The record of Miocene climatic events in AND-2A drill core (Antarctica): Insights from provenance analyses of basement clasts. Global and Planetary Change 75:31–46, https://doi.org/10.1016/j.gloplacha.2010.10.002.

Savin, S.M., R.G. Douglas, and F.G. Stehli. 1975. Tertiary marine paleotemperatures. Geological Society of America Bulletin 86:1,499–1,510, https://doi.org/10.1130/0016-7606(1975)86<1499:TMP>2.0.CO;2.

Schouten, S., E.C. Hopmans, E. Schefuß, and J.S.S. Damsté. 2002. Distributional variations in marine crenarchaeotal membrane lipids: A new tool for reconstructing ancient sea water temperatures? Earth and Planetary Science Letters 204:265–274, https://doi.org/10.1016/S0012-821X(02)00979-2.

Seki, O., G.L. Foster, D.N. Schmidt, A. Mackensen, K. Kawamura, and R.D. Pancost. 2010. Alkenone and boron based Pliocene pCO2 records. Earth and Planetary Science Letters 292:201–211, https://doi.org/10.1016/j.epsl.2010.01.037.

Shakun, J.D., P.U. Clark, F. He, S.A. Marcott, A.C. Mix, Z. Liu, B. Otto-Bliesner, A. Schmittner, and E. Bard. 2012. Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation. Nature 484:49–54, https://doi.org/10.1038/nature10915.

Shepherd, A., D. Wingham, and E. Rignot. 2004. Warm ocean is eroding West Antarctic Ice Sheet. Geophysical Research Letters 31, L23402, https://doi.org/10.1029/2004GL021106.

Shevenell, A.E., A.E. Ingalls, E.W. Domack, and C. Kelly. 2011. Holocene Southern Ocean surface temperature variability west of the Antarctic Peninsula. Nature 470:250–254, https://doi.org/10.1038/nature09751.

Shevenell, A.E., Kennett, J.P., and D.W. Lea. 2008. Middle Miocene ice sheet dynamics, deep-sea temperatures and carbon cycling: A Southern Ocean Perspective. Geochemistry Geophysics Geosystems 9, Q02006, https://doi.org/10.1029/2007GC001736.

Shevenell, A.E., J.P. Kennett, and D.W. Lea. 2004. Middle Miocene Southern Ocean cooling and Antarctic cryosphere expansion. Science 305:1,766–1,770, https://doi.org/10.1126/science.1100061.

Sigman, D.M., M.P. Hain, and G.H. Haug. 2010. The polar ocean and glacial cycles in atmospheric CO2 concentration. Nature 466: 47–55, https://doi.org/10.1038/nature09149.
Sjunneskog, C., and F. Taylor. 2002. Postglacial marine diatom record of the Palmer Deep, Antarctic Peninsula (ODP Leg 178, Site 1098) 1. Total diatom abundance. Paleoceanography 17(3), 8003, https://doi.org/10.1029/2000PA000563.

Skinner, L., S. Fallon, C. Waelbroeck, E. Michel, and S. Barker. 2010. Ventilation of the deep Southern Ocean and deglacial CO2 rise. Science 28:1,147–1,151, https://doi.org/10.1126/science.1183627.

Stammerjohn, S.E., D.G. Martinson, R.C. Smith, and R.A Iannuzzi. 2008. Sea ice in the western Antarctic Peninsula region: Spatio-temporal variability from ecological and climate change perspectives. Deep Sea Research Part II 55:2,041–2,058, https://doi.org/10.1016/j.dsr2.2008.04.026.

Steig, E.J., D.P. Schneider, S.D. Rutherford, M.E. Mann, J.C. Comiso, and D.T. Shindell. 2009. Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature 457:459–462, https://doi.org/10.1038/nature07669.

Tauxe, L., C.E. Stickley, S. Sugisaki, P.K. Bijl, S.M. Bohaty, H. Brinkhuis, C. Escutia, J.A. Flores, A.J.P. Houben, M. Iwai, and others. 2012. Chronostratigraphic framework for the IODP Expedition 318 cores from the Wilkes Land Margin: Constraints for paleoceanographic reconstruction. Paleoceanography 27, PA2214, https://doi.org/10.1029/2012PA002308.

Turner, J., S.R. Colwell, G.J. Marshall, T.A. Lachlan-Cope, A.M. Carleton, P.D. Jones, V. Lagun, P.A. Reid, and S. Iagovkina. 2005. Antarctic climate change during the last 50 years. International Journal of Climatology 25:279–294, https://doi.org/10.1002/joc.1130.

Vaughan, D.G., G.J. Marshall, W.M. Connolley, C. Parkinson, R. Mulvaney, D.A. Hodgson, J.C. King, C.J. Pudsey, and J. Turner. 2003. Recent rapid regional climate warming on the Antarctic Peninsula. Climatic Change 60:243–274, https://doi.org/10.1023/A:1026021217991.

Verducci, M., L.M. Foresi, G.H. Scott, M. Sprovieri, F. Lirer, and N. Pelosi. 2009. The middle Miocene climate transition in the Southern Ocean: Evidence of paleoclimatic and hydrographic changes at Kerguelen plateau from planktonic foraminifers and stable isotopes. Palaeogeography, Palaeoclimatology, Palaeoecology 280:371–386, https://doi.org/10.1016/j.palaeo.2009.06.024.

Warny, S., R.A. Askin, M.J. Hannah, B.A.R. Mohr, J.I. Raine, D.M. Harwood, F. Florindo, and the SMS Science Team. 2009. Palynomorphs from a sediment core reveal a sudden remarkably warm Antarctica during the middle Miocene. Geology 37:955–958, https://doi.org/10.1130/G30139A.1.

Weaver, A.J., O.A. Seanko, P.U. Clark, and J.X. Mitrovica. 2003. Meltwater pulse 1A from Antarctica as a trigger of the Bølling-Allerød warm interval. Science 299:1,709–1,712, https://doi.org/10.1126/science.1081002.

Whitehead, J.M., and S.M. Bohaty. 2003. Pliocene summer sea surface temperature reconstruction using silicoflagellates from Southern Ocean ODP Site 1165. Paleoceanography 18(3), 1075, https://doi.org/10.1029/2002PA000829.

Whitehead, J.M., S. Wotherspoon, and S.M. Bohaty. 2005. Minimal Antarctic sea ice during the Pliocene. Geology 33:137–140, https://doi.org/10.1130/G21013.1.

Williams, M., A.E. Nelson, J.L. Smellie, M.J. Leng, A.L.A. Johnson, D.R. Jarram, A.M. Haywood, V.L. Peck, J. Zalasiewicz, C. Bennett, and B.R. Schöne. 2010. Sea ice extent and seasonality for the Early Pliocene northern Weddell Sea. Palaeogeography, Palaeoclimatology, Palaeoecology 292:306–318, https://doi.org/10.1016/j.palaeo.2010.04.003.

Williams, T., T. van de Flierdt, S.R. Hemming, E. Chung, M. Roy, and S.L. Goldstein. 2010. Evidence for iceberg armadas from East Antarctica in the Southern Ocean during the late Miocene and early Pliocene. Earth and Planetary Science Letters 290:351–361, https://doi.org/10.1016/j.epsl.2009.12.031.

Zachos, J., M. Pagani, L. Sloan, E. Thomas, and K. Billups. 2001. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 292:686–693, https://doi.org/10.1126/science.1059412.