Articles | Volume 11, issue 10
https://doi.org/10.5194/cp-11-1313-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Special issue:
https://doi.org/10.5194/cp-11-1313-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
07 Oct 2015
Research article |
| 07 Oct 2015
Frequency, magnitude and character of hyperthermal events at the onset of the Early Eocene Climatic Optimum
V. Lauretano
CORRESPONDING AUTHOR
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584 CS, Utrecht, the Netherlands
K. Littler
Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
now at: Camborne School of Mines, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
M. Polling
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584 CS, Utrecht, the Netherlands
J. C. Zachos
Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
L. J. Lourens
Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584 CS, Utrecht, the Netherlands
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Clim. Past, 12, 1151–1163, https://doi.org/10.5194/cp-12-1151-2016, https://doi.org/10.5194/cp-12-1151-2016, 2016
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J. H. C. Bosmans, F. J. Hilgen, E. Tuenter, and L. J. Lourens
Clim. Past, 11, 1335–1346, https://doi.org/10.5194/cp-11-1335-2015, https://doi.org/10.5194/cp-11-1335-2015, 2015
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Our study shows that the influence of obliquity (the tilt of Earth's rotational axis) can be explained through changes in the insolation gradient across the tropics. This explanation is fundamentally different from high-latitude mechanisms that were previously often inferred to explain obliquity signals in low-latitude paleoclimate records, for instance glacial fluctuations. Our study is based on state-of-the-art climate model experiments.
T. Westerhold, U. Röhl, T. Frederichs, S. M. Bohaty, and J. C. Zachos
Clim. Past, 11, 1181–1195, https://doi.org/10.5194/cp-11-1181-2015, https://doi.org/10.5194/cp-11-1181-2015, 2015
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Testing hypotheses for mechanisms and dynamics of past climate change relies on the accuracy of geological dating. Development of a highly accurate geological timescale for the Cenozoic Era has previously been hampered by discrepancies between radioisotopic and astronomical dating methods, as well as a stratigraphic gap in the middle Eocene. We close this gap and provide a fundamental advance in establishing a reliable and highly accurate geological timescale for the last 66 million years.
C. J. Hollis, B. R. Hines, K. Littler, V. Villasante-Marcos, D. K. Kulhanek, C. P. Strong, J. C. Zachos, S. M. Eggins, L. Northcote, and A. Phillips
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B. S. Slotnick, V. Lauretano, J. Backman, G. R. Dickens, A. Sluijs, and L. Lourens
Clim. Past, 11, 473–493, https://doi.org/10.5194/cp-11-473-2015, https://doi.org/10.5194/cp-11-473-2015, 2015
L. B. Stap, R. S. W. van de Wal, B. de Boer, R. Bintanja, and L. J. Lourens
Clim. Past, 10, 2135–2152, https://doi.org/10.5194/cp-10-2135-2014, https://doi.org/10.5194/cp-10-2135-2014, 2014
J. S. Eldrett, D. R. Greenwood, M. Polling, H. Brinkhuis, and A. Sluijs
Clim. Past, 10, 759–769, https://doi.org/10.5194/cp-10-759-2014, https://doi.org/10.5194/cp-10-759-2014, 2014
D. A. Hodell, L. Lourens, D. A. V. Stow, J. Hernández-Molina, C. A. Alvarez Zarikian, and the Shackleton Site Project Members
Sci. Dril., 16, 13–19, https://doi.org/10.5194/sd-16-13-2013, https://doi.org/10.5194/sd-16-13-2013, 2013
R. S. W. van de Wal, B. de Boer, L. J. Lourens, P. Köhler, and R. Bintanja
Clim. Past, 7, 1459–1469, https://doi.org/10.5194/cp-7-1459-2011, https://doi.org/10.5194/cp-7-1459-2011, 2011
D. Liebrand, L. J. Lourens, D. A. Hodell, B. de Boer, R. S. W. van de Wal, and H. Pälike
Clim. Past, 7, 869–880, https://doi.org/10.5194/cp-7-869-2011, https://doi.org/10.5194/cp-7-869-2011, 2011
Related subject area
Subject: Carbon Cycle | Archive: Marine Archives | Timescale: Cenozoic
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Export productivity is part of the global carbon cycle, influencing the climate system via biological pump. About 34 million years ago, the Earth's climate experienced a climate transition from a greenhouse state to an icehouse state with the onset of ice sheets in Antarctica. Our study shows important productivity events in the Southern Ocean preceding this climatic shift. Our findings strongly indicate that the biological pump potentially played an important role in that past climate change.
Mitchell Lyle and Annette Olivarez Lyle
Clim. Past Discuss., https://doi.org/10.5194/cp-2024-34, https://doi.org/10.5194/cp-2024-34, 2024
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Studies of past warm intervals show that greenhouse gases are a key factor to warm the earth. However, feedbacks are needed to maintain warm periods. We investigate whether changes in the ocean degradation depth for plankton-produced organic matter might change ocean carbon storage. Low Corg burial in sediments of the Miocene Climate Optimum (MCO) warm interval relative to more recent periods fits with less efficient Corg transfer to the abyss, maintaining a higher level of MCO atmospheric CO2.
Morgan T. Jones, Ella W. Stokke, Alan D. Rooney, Joost Frieling, Philip A. E. Pogge von Strandmann, David J. Wilson, Henrik H. Svensen, Sverre Planke, Thierry Adatte, Nicolas Thibault, Madeleine L. Vickers, Tamsin A. Mather, Christian Tegner, Valentin Zuchuat, and Bo P. Schultz
Clim. Past, 19, 1623–1652, https://doi.org/10.5194/cp-19-1623-2023, https://doi.org/10.5194/cp-19-1623-2023, 2023
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There are periods in Earth’s history when huge volumes of magma are erupted at the Earth’s surface. The gases released from volcanic eruptions and from sediments heated by the magma are believed to have caused severe climate changes in the geological past. We use a variety of volcanic and climatic tracers to assess how the North Atlantic Igneous Province (56–54 Ma) affected the oceans and atmosphere during a period of extreme global warming.
Christopher J. Hollis, Sebastian Naeher, Christopher D. Clowes, B. David A. Naafs, Richard D. Pancost, Kyle W. R. Taylor, Jenny Dahl, Xun Li, G. Todd Ventura, and Richard Sykes
Clim. Past, 18, 1295–1320, https://doi.org/10.5194/cp-18-1295-2022, https://doi.org/10.5194/cp-18-1295-2022, 2022
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Previous studies of Paleogene greenhouse climates identified short-lived global warming events, termed hyperthermals, that provide insights into global warming scenarios. Within the same time period, we have identified a short-lived cooling event in the late Paleocene, which we term a hypothermal, that has potential to provide novel insights into the feedback mechanisms at work in a greenhouse climate.
Mitchell Lyle, Anna Joy Drury, Jun Tian, Roy Wilkens, and Thomas Westerhold
Clim. Past, 15, 1715–1739, https://doi.org/10.5194/cp-15-1715-2019, https://doi.org/10.5194/cp-15-1715-2019, 2019
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Ocean sediment records document changes in Earth’s carbon cycle and ocean productivity. We present 8 Myr CaCO3 and bulk sediment records from seven eastern Pacific scientific drill sites to identify intervals of excess CaCO3 dissolution (high carbon storage in the oceans) and excess burial of plankton hard parts indicating high productivity. We define the regional extent of production intervals and explore the impact of the closure of the Atlantic–Pacific Panama connection on CaCO3 burial.
Akitomo Yamamoto, Ayako Abe-Ouchi, Rumi Ohgaito, Akinori Ito, and Akira Oka
Clim. Past, 15, 981–996, https://doi.org/10.5194/cp-15-981-2019, https://doi.org/10.5194/cp-15-981-2019, 2019
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Proxy records of glacial oxygen change provide constraints on the contribution of the biological pump to glacial CO2 decrease. Here, we report our numerical simulation which successfully reproduces records of glacial oxygen changes and shows the significance of iron supply from glaciogenic dust. Our model simulations clarify that the enhanced efficiency of the biological pump is responsible for glacial CO2 decline of more than 30 ppm and approximately half of deep-ocean deoxygenation.
David I. Armstrong McKay and Timothy M. Lenton
Clim. Past, 14, 1515–1527, https://doi.org/10.5194/cp-14-1515-2018, https://doi.org/10.5194/cp-14-1515-2018, 2018
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This study uses statistical analyses to look for signs of declining resilience (i.e. greater sensitivity to small shocks) in the global carbon cycle and climate system across the Palaeocene–Eocene Thermal Maximum (PETM), a global warming event 56 Myr ago driven by rapid carbon release. Our main finding is that carbon cycle resilience declined in the 1.5 Myr beforehand (a time of significant volcanic emissions), which is consistent with but not proof of a carbon release tipping point at the PETM.
Joost Frieling, Gert-Jan Reichart, Jack J. Middelburg, Ursula Röhl, Thomas Westerhold, Steven M. Bohaty, and Appy Sluijs
Clim. Past, 14, 39–55, https://doi.org/10.5194/cp-14-39-2018, https://doi.org/10.5194/cp-14-39-2018, 2018
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Past periods of rapid global warming such as the Paleocene–Eocene Thermal Maximum are used to study biotic response to climate change. We show that very high peak PETM temperatures in the tropical Atlantic (~ 37 ºC) caused heat stress in several marine plankton groups. However, only slightly cooler temperatures afterwards allowed highly diverse plankton communities to bloom. This shows that tropical plankton communities may be susceptible to extreme warming, but may also recover rapidly.
Christoph Heinze, Babette A. A. Hoogakker, and Arne Winguth
Clim. Past, 12, 1949–1978, https://doi.org/10.5194/cp-12-1949-2016, https://doi.org/10.5194/cp-12-1949-2016, 2016
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Sensitivities of sediment tracers to changes in carbon cycle parameters were determined with a global ocean model. The sensitivities were combined with sediment and ice core data. The results suggest a drawdown of the sea surface temperature by 5 °C, an outgassing of the land biosphere by 430 Pg C, and a strengthening of the vertical carbon transfer by biological processes at the Last Glacial Maximum. A glacial change in marine calcium carbonate production can neither be proven nor rejected.
Valeria Luciani, Gerald R. Dickens, Jan Backman, Eliana Fornaciari, Luca Giusberti, Claudia Agnini, and Roberta D'Onofrio
Clim. Past, 12, 981–1007, https://doi.org/10.5194/cp-12-981-2016, https://doi.org/10.5194/cp-12-981-2016, 2016
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The symbiont-bearing planktic foraminiferal genera Morozovella and Acarinina were among the most important calcifiers of the early Paleogene tropical and subtropical oceans. However, a remarkable and permanent switch in the relative abundance of these genera happened in the early Eocene. We show that this switch occurred at low-latitude sites near the start of the Early Eocene Climatic Optimum (EECO), a multi-million-year interval when Earth surface temperatures reached their Cenozoic maximum.
Claudia Agnini, David J. A. Spofforth, Gerald R. Dickens, Domenico Rio, Heiko Pälike, Jan Backman, Giovanni Muttoni, and Edoardo Dallanave
Clim. Past, 12, 883–909, https://doi.org/10.5194/cp-12-883-2016, https://doi.org/10.5194/cp-12-883-2016, 2016
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In this paper we present records of stable C and O isotopes, CaCO3 content, and changes in calcareous nannofossil assemblages in a upper Paleocene-lower Eocene rocks now exposed in northeast Italy. Modifications of nannoplankton assemblages and carbon isotopes are strictly linked one to each other and always display the same ranking and spacing. The integration of this two data sets represents a significative improvement in our capacity to correlate different sections at a very high resolution.
T. Westerhold, U. Röhl, T. Frederichs, S. M. Bohaty, and J. C. Zachos
Clim. Past, 11, 1181–1195, https://doi.org/10.5194/cp-11-1181-2015, https://doi.org/10.5194/cp-11-1181-2015, 2015
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Testing hypotheses for mechanisms and dynamics of past climate change relies on the accuracy of geological dating. Development of a highly accurate geological timescale for the Cenozoic Era has previously been hampered by discrepancies between radioisotopic and astronomical dating methods, as well as a stratigraphic gap in the middle Eocene. We close this gap and provide a fundamental advance in establishing a reliable and highly accurate geological timescale for the last 66 million years.
B. S. Slotnick, V. Lauretano, J. Backman, G. R. Dickens, A. Sluijs, and L. Lourens
Clim. Past, 11, 473–493, https://doi.org/10.5194/cp-11-473-2015, https://doi.org/10.5194/cp-11-473-2015, 2015
J. S. Eldrett, D. R. Greenwood, M. Polling, H. Brinkhuis, and A. Sluijs
Clim. Past, 10, 759–769, https://doi.org/10.5194/cp-10-759-2014, https://doi.org/10.5194/cp-10-759-2014, 2014
G. R. Dickens
Clim. Past, 7, 831–846, https://doi.org/10.5194/cp-7-831-2011, https://doi.org/10.5194/cp-7-831-2011, 2011
A. Sluijs, P. K. Bijl, S. Schouten, U. Röhl, G.-J. Reichart, and H. Brinkhuis
Clim. Past, 7, 47–61, https://doi.org/10.5194/cp-7-47-2011, https://doi.org/10.5194/cp-7-47-2011, 2011
R. E. M. Rickaby, J. Henderiks, and J. N. Young
Clim. Past, 6, 771–785, https://doi.org/10.5194/cp-6-771-2010, https://doi.org/10.5194/cp-6-771-2010, 2010
Cited articles
Abels, H. A., Clyde, W. C., Gingerich, P. D., Hilgen, F. J., Fricke, H. C., Bowen, G. J., and Lourens, L. J.: Terrestrial carbon isotope excursions and biotic change during Palaeogene hyperthermals, Nat. Geosci., 5, 326–329, https://doi.org/10.1038/ngeo1427, 2012.
Abels, H. A., Lauretano, V., van Yperen, A., Hopman, T., Zachos, J. C., Lourens, L. J., Gingerich, P. D., and Bowen, G. J.: Carbon isotope excursions in paleosol carbonate marking five early Eocene hyperthermals in the Bighorn Basin, Wyoming, Clim. Past Discuss., 11, 1857–1885, https://doi.org/10.5194/cpd-11-1857-2015, 2015.
Agnini, C., Macri, P., Backman, J., Brinkhuis, H., Fornaciari, E., Giusberti, L., Luciani, V., Rio, D., Sluijs, A., and Speranza, F.: An early Eocene carbon cycle perturbation at 52.5 Ma in the Southern Alps: Chronology and biotic response, Paleoceanography, 24, PA2209, https://doi.org/10.1029/2008PA001649, 2009.
Bemis, B. E., Spero, H. J., Bijma, J., and Lea, D. W.: Reevaluation of the oxygen isotopic composition of planktonic foraminifera: Experimental results and revised paleotemperature equations, Paleoceanography, 13, 150–160, 1998.
Bijl, P. K., Schouten, S., Sluijs, A., Reichart, G.-J., Zachos, J. C., and Brinkhuis, H.: Early Palaeogene temperature evolution of the southwest Pacific Ocean, Nature, 461, 776–779, https://doi.org/10.1038/nature08399, 2009.
Cramer, B. S., Wright, J. D., Kent, D. V., and Aubry, M.-P.: Orbital climate forcing of δ13C excursions in the late Paleocene-early Eocene (chrons C24n–C25n), Paleoceanography, 18, 1097, https://doi.org/10.1029/2003PA000909, 2003.
D'haenens, S., Bornemann, A., Stassen, P., and Speijer, R. P.: Multiple early Eocene benthic foraminiferal assemblage and δ13C fluctuations at DSDP Site 401 (Bay of Biscay – NE Atlantic), Mar. Micropaleontol., 88–89, 15–35, https://doi.org/10.1016/j.marmicro.2012.02.006, 2012.
DeConto, R. M., Galeotti, S., Pagani, M., Tracy, D., Schaefer, K., Zhang, T., Pollard, D., and Beerling, D. J.: Past extreme warming events linked to massive carbon release from thawing permafrost, Nature, 484, 87–91, https://doi.org/10.1038/nature10929, 2012.
Dickens, G. R.: Rethinking the global carbon cycle with a large, dynamic and microbially mediated gas hydrate capacitor, Earth Planet. Sci. Lett., 213, 169–183, https://doi.org/10.1016/S0012-821X(03)00325-X, 2003.
Dickens, G. R, O'Neil, J. R., Rea, D. K., and Owen, R. M.: Dissociation of oceanic methane hydrate as a cause of the carbon isotope excursion at the end of the Paleocene, Paleoceanography, 10, 965–971, 1995.
Dinarès-Turell, J., Westerhold, T., Pujalte, V., Röhl, U., and Kroon, D.: Astronomical calibration of the Danian stage (Early Paleocene) revisited: Settling chronologies of sedimentary records across the Atlantic and Pacific Oceans, Earth Planet. Sci. Lett., 405, 119–131, https://doi.org/10.1016/j.epsl.2014.08.027, 2014.
Galeotti, S., Krishnan, S., Pagani, M., Lanci, L., Gaudio, A., Zachos, J. C., Monechi, S., Morelli, G., and Lourens, L. J.: Orbital chronology of Early Eocene hyperthermals from the Contessa Road section, central Italy, Earth Planet. Sci. Lett., 290, 192–200, https://doi.org/10.1016/j.epsl.2009.12.021, 2010.
Gibbs, S. J., Bown, P. R., Murphy, B. H., Sluijs, A., Edgar, K. M., Pälike, H., Bolton, C. T., and Zachos, J. C.: Scaled biotic disruption during early Eocene global warming events, Biogeosciences, 9, 4679–4688, https://doi.org/10.5194/bg-9-4679-2012, 2012.
Hilgen, F. J., Kuiper, K. F., and Lourens, L. J.: Evaluation of the astronomical time scale for the Paleocene and earliest Eocene, Earth Planet. Sci. Lett., 300, 139–151, https://doi.org/10.1016/j.epsl.2010.09.044, 2010.
Hilgen, F. J., Abels, H. A., Kuiper, K. F., Lourens, L. J., and Wolthers, M.: Towards a stable astronomical time scale for the Paleocene: Aligning Shatsky Rise with the Zumaia – Walvis Ridge ODP Site 1262 composite, Newsletters Stratigr., 48, 91–110, https://doi.org/10.1127/nos/2014/0054, 2015.
Holbourn, A., Kuhnt, W., Schulz, M., Flores, J.-A., and Andersen, N.: Orbitally-paced climate evolution during the middle Miocene "Monterey" carbon isotope excursion, Earth Planet. Sci. Lett. 261, 534–550, 2007.
Hönisch, B., Ridgwell, A., Schmidt, D. N., Thomas, E., Gibbs, S. J., Sluijs, A., Zeebe, R., Kump, L., Martindale, R. C., Greene, S. E., Kiessling, W., Ries, J., Zachos, J. C., Royer, D. L., Barker, S., Marchitto, T. M., Moyer, R., Pelejero, C., Ziveri, P., Foster, G. L., and Williams, B.: The geological record of ocean acidification, Science, 335, 1058–63, https://doi.org/10.1126/science.1208277, 2012.
Hut, G.: Stable isotope reference samples for geochemical and hydrological investigations, Consultants Group Meeting, report, Int. At. Energy Agency,Vienna, Austria, 42 pp., 1987.
Jennions, S. M., Thomas, E., Schmidt, D. N., Lunt, D., and Ridgwell, A.: Changes in benthic ecosystems and ocean circulation in the Southeast Atlantic across Eocene Thermal Maximum 2, Paleoceanography, 30, https://doi.org/10.1002/2015PA002821, 2015.
Kennett, J. P. and Stott, L. D.: Abrupt deep-sea warming, palaeoceanographic changes and benthic extinctions at the end of the Palaeocene, Nature, 353, 225–229, https://doi.org/10.1038/353225a0, 1991.
Kirtland Turner, S., Sexton, P. F., Charles, C. D., and Norris, R. D.: Persistence of carbon release events through the peak of early Eocene global warmth, Nat. Geosci., 12, 1–17, https://doi.org/10.1038/ngeo2240, 2014.
Kuiper, K. F., Deino, A., Hilgen, F. J., Krijgsman, W., Renne, P. R., and Wijbrans, J. R.: Synchronizing rock clocks of Earth history., Science, 320, 500–504, https://doi.org/10.1126/science.1154339, 2008.
Kurtz, A. C., Kump, L. R., Arthur, M. A., Zachos, J. C., and Paytan, A.: Early Cenozoic decoupling of the global carbon and sulfur cycles, Paleoceanography, 18, 1090, \https://doi.org/10.1029/2003PA000908, 2003.
Laskar, J., Fienga, A., Gastineau, M., and Manche, H.: La2010: A new orbital solution for the long term motion of the Earth, Astron. Astrophys., 532, 15 pp., https://doi.org/10.1051/0004-6361/201116836, 2011.
Liebrand, D., Lourens, L. J., Hodell, D. A., de Boer, B., van de Wal, R. S. W., and Pälike, H.: Antarctic ice sheet and oceanographic response to eccentricity forcing during the early Miocene, Clim. Past, 7, 869–880, https://doi.org/10.5194/cp-7-869-2011, 2011.
Littler, K., Röhl, U., Westerhold, T., and Zachos, J. C.: A high-resolution benthic stable-isotope record for the South Atlantic: Implications for orbital-scale changes in Late Paleocene-Early Eocene climate and carbon cycling, Earth Planet. Sci. Lett., 401, 18–30, https://doi.org/10.1016/j.epsl.2014.05.054, 2014.
Lourens, L. J., Sluijs, A., Kroon, D., Zachos, J. C., Thomas, E., Röhl, U., Bowles, J., and Raffi, I.: Astronomical pacing of late Palaeocene to early Eocene global warming events, Nature, 435, 1083–1087, https://doi.org/10.1038/nature03814, 2005.
Lunt, D. J., Valdes, P. J., Jones, T. D., Ridgwell, A., Haywood, A. M., Schmidt, D. N., Marsh, R., and Maslin, M.: CO2-driven ocean circulation changes as an amplifier of Paleocene-Eocene thermal maximum hydrate destabilization, Geology, 38, 875–878, https://doi.org/10.1130/G31184.1, 2010.
Lunt, D. J., Ridgwell, A., Sluijs, A., Zachos, J. C., Hunter, S., and Haywood, A.: A model for orbital pacing of methane hydrate destabilization during the Palaeogene, Nat. Geosci., 4, 775–778, https://doi.org/10.1038/ngeo1266, 2011.
McInerney, F. A. and Wing, S. L.: The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future, Annu. Rev. Earth Planet. Sci., 39, 489–516, https://doi.org/10.1146/annurev-earth-040610-133431, 2011.
Nicolo, M. J., Dickens, G. R., Hollis, C. J., and Zachos, J. C.: Multiple early Eocene hyperthermals: Their sedimentary expression on the New Zealand continental margin and in the deep sea, Geology, 35, 699, https://doi.org/10.1130/G23648A.1, 2007.
Paillard, D., Labeyrie, L., and Yiou, P.: Macintosh program performs time-series analysis, Eos Trans. AGU, 77, 379, 1996.
Pälike, H., Norris, R. D., Herrle, J. O., Wilson, P. A., Coxall, H. K., Lear, C. H., Shackleton, N. J., Tripati, A. K., and Wade, B. S.: The heart- beat of the Oligocene climate system, Science, 314, 1894–1998, 2006.
Renne, P. R., Deino, A. L., Hilgen, F. J., Kuiper, K. F., Mark, D. F., Mitchell, W. S., Morgan, L. E., Mundil, R., and Smit, J.: Time scales of critical events around the Cretaceous-Paleogene boundary, Science, 339, 684–687, \https://doi.org/10.1126/science.1230492, 2013.
Röhl, U., Westerhold, T., Monechi, S., Thomas, E., Zachos, J. C., and Donner, B.: The Third and Final Early Eocene Thermal Maximum: Characteristics, Timing and Mechanisms of the `X' Event, GSA Annual Meeting 37, Geological Society of America, Salt Lake City, USA, 264 pp., 2005.
Sexton, P. F., Norris, R. D., Wilson, P. A., Pälike, H., Westerhold, T., Röhl, U., Bolton, C. T., and Gibbs, S.: Eocene global warming events driven by ventilation of oceanic dissolved organic carbon, Nature, 471, 349–352, https://doi.org/10.1038/nature09826, 2011.
Shackleton, N. J. and Hall, M. A: The late Miocene stable isotope record, Site 926, Proc. Ocean Drill. Program Sci. Results, 154, 367–373, https://doi.org/10.2973/odp.proc.sr.154.119.1997, 1997.
Shackleton, N. J., Hall, M. A., and Boersma, A.: Oxygen and carbon isotope data from Leg-74 foraminifers, Initial Rep. Deep Sea Drill. Project, 74, 599–612, 1984.
Slotnick, B. S., Dickens, G. R., Nicolo, M. J., Hollis, C. J., Crampton, J. S., Zachos, J. C., and Sluijs, A.: Large-Amplitude Variations in Carbon Cycling and Terrestrial Weathering during the Latest Paleocene and Earliest Eocene: The Record at Mead Stream, New Zealand, J. Geol., 120, 487–505, https://doi.org/10.1086/666743, 2012.
Sluijs, A., Brinkhuis, H., Schouten, S., Bohaty, S. M., John, C. M., Zachos, J. C., Reichart, G.-J., Sinninghe Damsté, J. S., Crouch, E. M., and Dickens, G. R.: Environmental precursors to rapid light carbon injection at the Palaeocene/Eocene boundary, Nature, 450, 1218–1221, https://doi.org/10.1038/nature06400, 2007.
Stap, L., Sluijs, A., Thomas, E., and Lourens, L. J.: Patterns and magnitude of deep sea carbonate dissolution during Eocene Thermal Maximum 2 and H2, Walvis Ridge, southeastern Atlantic Ocean, Paleoceanography, 24, PA1211, https://doi.org/10.1029/2008PA001655, 2009.
Stap, L., Lourens, L. J., Thomas, E., Sluijs, A., Bohaty, S., and Zachos, J. C.: High-resolution deep-sea carbon and oxygen isotope records of Eocene Thermal Maximum 2 and H2, Geology, 38, 607–610, https://doi.org/10.1130/G30777.1, 2010.
Thomas, E. and Shackleton, N. J.: The Paleocene-Eocene benthic foraminiferal extinction and stable isotope anomalies, Geol. Soc. London, Spec. Publ., 101, 401–441, \https://doi.org/10.1144/GSL.SP.1996.101.01.20, 1996.
Westerhold, T. and Röhl, U.: High resolution cyclostratigraphy of the early Eocene – new insights into the origin of the Cenozoic cooling trend, Clim. Past, 5, 309–327, https://doi.org/10.5194/cp-5-309-2009, 2009.
Westerhold, T., Röhl, U., Laskar, J., Raffi, I., Bowles, J., Lourens, L. J., and Zachos, J. C.: On the duration of magnetochrons C24r and C25n and the timing of early Eocene global warming events: Implications from the Ocean Drilling Program Leg 208 Walvis Ridge depth transect, Paleoceanography, 22, PA2201, https://doi.org/10.1029/2006PA001322, 2007.
Westerhold, T., Röhl, U., Raffi, I., Fornaciari, E., Monechi, S., Reale, V., Bowles, J., and Evans, H. F.: Astronomical calibration of the Paleocene time, Palaeogeogr. Palaeoclimatol. Palaeoecol., 257, 377–403, https://doi.org/10.1016/j.palaeo.2007.09.016, 2008.
Zachos, J. C., Pagani, M., Sloan, L., Thomas, E., and Billups, K.: Trends, rhythms, and aberrations in global climate 65 Ma to present, Science, 292, 686–693, 2001a.
Zachos, J. C., Kroon, D., and Blum, P.: ODP Leg 208: The early Cenozoic extreme climates transect along Walvis Ridge, Proceedings of the Ocean Drilling Program Initial Reports, 208 pp., 2004.
Zachos, J. C., Röhl, U., Schellenberg, S. A., Sluijs, A., Hodell, D. A., Kelly, D. C., Thomas, E., Nicolo, M., Raffi, I., Lourens, L. J., McCarren, H., and Kroon, D.: Rapid acidification of the ocean during the Paleocene-Eocene thermal maximum, Science, 308, 1611–1615, https://doi.org/10.1126/science.1109004, 2005.
Zachos, J. C., Dickens, G. R., and Zeebe, R. E.: An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics, Nature, 451, 279–283, https://doi.org/10.1038/nature06588, 2008.
Zachos, J. C., McCarren, H., Murphy, B., Röhl, U. and Westerhold, T.: Tempo and scale of late Paleocene and early Eocene carbon isotope cycles: Implications for the origin of hyperthermals, Earth Planet. Sci. Lett., 299, 242–249, https://doi.org/10.1016/j.epsl.2010.09.004, 2010.
Zeebe, R. E. and Zachos, J. C.: Long-term legacy of massive carbon input to the Earth system: Anthropocene versus Eocene, Philos. Trans. A. Math. Phys. Eng. Sci., 371, 20120006, https://doi.org/10.1098/rsta.2012.0006, 2013.
Short summary
Several episodes of global warming took place during greenhouse conditions in the early Eocene and are recorded in deep-sea sediments. The stable carbon and oxygen isotope records are used to investigate the magnitude of six of these events describing their effects on the global carbon cycle and the associated temperature response. Findings indicate that these events share a common nature and hint to the presence of multiple sources of carbon release.
Several episodes of global warming took place during greenhouse conditions in the early Eocene...
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