180 results on '"Bijl, Peter K."'
Search Results
2. Reconciling Southern Ocean fronts equatorward migration with minor Antarctic ice volume change during Miocene cooling
- Author
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Hou, Suning, Stap, Lennert B., Paul, Ryan, Nelissen, Mei, Hoem, Frida S., Ziegler, Martin, Sluijs, Appy, Sangiorgi, Francesca, and Bijl, Peter K.
- Published
- 2023
- Full Text
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3. Resolution dependency of sinking Lagrangian particles in ocean general circulation models
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Nooteboom, Peter D., Delandmeter, Philippe, van Sebille, Erik, Bijl, Peter K., Dijkstra, Henk A., and von der Heydt, Anna S.
- Subjects
Physics - Atmospheric and Oceanic Physics - Abstract
Any type of non-buoyant material in the ocean is transported horizontally by currents during its sinking journey. This lateral transport can be far from negligible for small sinking velocities. To estimate its magnitude and direction, the material is often modelled as a set of Lagrangian particles advected by current velocities that are obtained from Ocean General Circulation Models (OGCMs). State-of-the-art OGCMs are strongly eddying, similar to the real ocean, providing results with a spatial resolution on the order of 10 km on a daily frequency. While the importance of eddies in OGCMs is well-appreciated in the physical oceanographic community, other marine research communities may not. To demonstrate how much the absence of mesoscale features in low-resolution models influences the Lagrangian particle transport, we simulate the transport of sinking Lagrangian particles using low- and high-resolution global OGCMs, and assess the lateral transport differences resulting from the difference in spatial and temporal model resolution. We find major differences between the transport in the non-eddying OGCM and in the eddying OGCM. Addition of stochastic noise to the particle trajectories in the non-eddying OGCM parameterises the effect of eddies well in some cases. The effect of a coarser temporal resolution (5-daily) is smaller compared to a coarser spatial resolution (0.1$^{\circ}$ versus 1$^{\circ}$ horizontally). We recommend to use sinking Lagrangian particles, representing e.g. marine snow, microplankton or sinking plastic, only with velocity fields from eddying OGCMs, requiring high-resolution models in e.g. paleoceanographic studies. To increase the accessibility of our particle trace simulations, we launch planktondrift.science.uu.nl, an online tool to reconstruct the surface origin of sedimentary particles in a specific location.
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- 2020
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4. The DeepMIP contribution to PMIP4: methodologies for selection, compilation and analysis of latest Paleocene and early Eocene climate proxy data, incorporating version 0.1 of the DeepMIP database
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Hollis, Christopher J, Jones, Tom Dunkley, Anagnostou, Eleni, Bijl, Peter K, Cramwinckel, Margot J, Cui, Ying, Dickens, Gerald R, Edgar, Kirsty M, Eley, Yvette, Evans, David, Foster, Gavin L, Frieling, Joost, Inglis, Gordon N, Kennedy, Elizabeth M, Kozdon, Reinhard, Lauretano, Vittoria, Lear, Caroline H, Littler, Kate, Lourens, Lucas, Meckler, A Nele, Naafs, B David A, Paelike, Heiko, Pancost, Richard D, Pearson, Paul N, Roehl, Ursula, Royer, Dana L, Salzmann, Ulrich, Schubert, Brian A, Seebeck, Hannu, Sluijs, Appy, Speijer, Robert P, Stassen, Peter, Tierney, Jessica, Tripati, Aradhna, Wade, Bridget, Westerhold, Thomas, Witkowski, Caitlyn, Zachos, James C, Zhang, Yi Ge, Huber, Matthew, and Lunt, Daniel J
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Earth Sciences - Abstract
Abstract. The early Eocene (56 to 48 million years ago) is inferred to havebeen the most recent time that Earth's atmospheric CO2 concentrationsexceeded 1000 ppm. Global mean temperatures were also substantially warmerthan those of the present day. As such, the study of early Eocene climate provides insightinto how a super-warm Earth system behaves and offers an opportunity toevaluate climate models under conditions of high greenhouse gas forcing. TheDeep Time Model Intercomparison Project (DeepMIP) is a systematicmodel–model and model–data intercomparison of three early Paleogene timeslices: latest Paleocene, Paleocene–Eocene thermal maximum (PETM) and earlyEocene climatic optimum (EECO). A previous article outlined the modelexperimental design for climate model simulations. In this article, weoutline the methodologies to be used for the compilation and analysis ofclimate proxy data, primarily proxies for temperature and CO2. Thispaper establishes the protocols for a concerted and coordinated effort tocompile the climate proxy records across a wide geographic range. Theresulting climate “atlas” will be used to constrain and evaluate climatemodels for the three selected time intervals and provide insights into themechanisms that control these warm climate states. We provide version 0.1 ofthis database, in anticipation that this will be expanded in subsequentpublications.
- Published
- 2019
5. Strength and variability of the Oligocene Southern Ocean surface temperature gradient
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Hoem, Frida S., Sauermilch, Isabel, Aleksinski, Adam K., Huber, Matthew, Peterse, Francien, Sangiorgi, Francesca, and Bijl, Peter K.
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- 2022
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6. Climate variability, heat distribution, and polar amplification in the warm unipolar "icehouse" of the Oligocene.
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Jenny, Dominique K. L. L., Reichgelt, Tammo, O'Brien, Charlotte L., Liu, Xiaoqing, Bijl, Peter K., Huber, Matthew, and Sluijs, Appy
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LAND surface temperature ,OCEAN temperature ,GLOBAL warming ,OLIGOCENE Epoch ,ATMOSPHERIC models - Abstract
The Oligocene (33.9–23.03 Ma) had warm climates with flattened meridional temperature gradients, while Antarctica retained a significant cryosphere. These may pose imperfect analogues to distant future climate states with unipolar icehouse conditions. Although local and regional climate and environmental reconstructions of Oligocene conditions are available, the community lacks synthesis of regional reconstructions. To provide a comprehensive overview of marine and terrestrial climate and environmental conditions in the Oligocene, and a reconstruction of trends through time, we review marine and terrestrial proxy records and compare these to numerical climate model simulations of the Oligocene. Results, based on the present relatively sparse data, suggest temperatures around the Equator that are similar to modern temperatures. Sea surface temperatures (SSTs) show patterns similar to land temperatures, with warm conditions at mid- and high latitudes (∼60 –90°), especially in the Southern Hemisphere (SH). Vegetation-based precipitation reconstructions of the Oligocene suggest regionally drier conditions compared to modern times around the Equator. When compared to proxy data, climate model simulations overestimate Oligocene precipitation in most areas, particularly the tropics. Temperatures around the mid- to high latitudes are generally underestimated in models compared to proxy data and tend to overestimate the warming in the tropics. In line with previous proxy-to-model comparisons, we find that models underestimate polar amplification and overestimate the Equator-to-pole temperature gradient suggested from the available proxy data. This further stresses the urgency of solving this widely recorded problem for past warm climates, such as the Oligocene. [ABSTRACT FROM AUTHOR]
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- 2024
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7. DINOSTRAT version 2.1-GTS2020
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Bijl, Peter K., primary
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- 2024
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8. Polar amplification of orbital-scale climate variability in the early Eocene greenhouse world.
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Fokkema, Chris D., Agterhuis, Tobias, Gerritsma, Danielle, de Goeij, Myrthe, Liu, Xiaoqing, de Regt, Pauline, Rice, Addison, Vennema, Laurens, Agnini, Claudia, Bijl, Peter K., Frieling, Joost, Huber, Matthew, Peterse, Francien, and Sluijs, Appy
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EOCENE Epoch ,OCEAN temperature ,ATMOSPHERIC carbon dioxide ,CARBON cycle ,FORCED migration ,GEOLOGICAL time scales - Abstract
Climate variability is typically amplified towards polar regions. The underlying causes, notably albedo and humidity changes, are challenging to accurately quantify with observations or models, thus hampering projections of future polar amplification. Polar amplification reconstructions from the ice-free early Eocene (∼56 –48 Ma) can exclude ice albedo effects, but the required tropical temperature records for resolving timescales shorter than multi-million years are lacking. Here, we reconstruct early Eocene tropical sea surface temperature variability by presenting an up to ∼4 kyr resolution biomarker-based temperature record from Ocean Drilling Program (ODP) Site 959, located in the tropical Atlantic Ocean. This record shows warming across multiple orbitally paced carbon cycle perturbations, coeval with high-latitude-derived deep-ocean bottom waters, showing that these events represent transient global warming events (hyperthermals). This implies that orbital forcing caused global temperature variability through carbon cycle feedbacks. Importantly, deep-ocean temperature variability was amplified by a factor of 1.7–2.3 compared to the tropical surface ocean, corroborating available long-term estimates. This implies that fast atmospheric feedback processes controlled meridional temperature gradients on multi-million year, as well as orbital, timescales during the early Eocene. Our combined records have several other implications. First, our amplification factor is somewhat larger than the same metric in fully coupled simulations of the early Eocene (1.1–1.3), suggesting that models slightly underestimate the non-ice-related – notably hydrological – feedbacks that cause polar amplification of climate change. Second, even outside the hyperthermals, we find synchronous eccentricity-forced temperature variability in the tropics and deep ocean that represent global mean sea surface temperature variability of up to 0.7 °C, which requires significant variability in atmospheric p CO 2. We hypothesize that the responsible carbon cycle feedbacks that are independent of ice, snow, and frost-related processes might play an important role in Phanerozoic orbital-scale climate variability throughout geological time, including Pleistocene glacial–interglacial climate variability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Southern Ocean control on atmospheric CO2 changes across late-Pliocene Marine Isotope Stage M2.
- Author
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Hou, Suning, Toebrock, Leonie, van der Linden, Mart, Rothstegge, Fleur, Ziegler, Martin, Lourens, Lucas J., and Bijl, Peter K.
- Abstract
During the Pliocene, atmospheric CO
2 concentrations (p CO2 ) were similar to today's and global average temperature was ~3 °C higher. However, the relationships and phasing between variability in climate and p CO2 on orbital time scales are not well understood. Specifically, questions remain about the nature of a lag of p CO2 relative to benthic foraminiferal δ18 O in the late-Pliocene Marine Isotope Stage M2 (3300 kiloannum ago, ka), which was longer than during the Pleistocene. Here, we present a multi-proxy paleoceanographic reconstruction of the late-Pliocene subantarctic zone, which is today one of the major ocean sinks of atmospheric CO2 . New dinoflagellate cyst assemblage data is combined with previously published sea surface temperature reconstructions, to reveal past surface conditions, including latitudinal migrations of the subtropical front (STF) over the late-Pliocene at ODP Site 1168, offshore west Tasmania. We observe strong oceanographic variability at the STF over glacial-interglacial timescales, especially across the M2 (3320–3260 ka). By providing tight and independent age constraints from benthic foraminiferal δ18 O, we find that, much more than benthic δ18 O or local SST, latitudinal migrations of the STF are tightly coupled to p CO2 variations across the M2. Specifically, a northerly position of the STF during M2 deglaciation coincides with generally low p CO2 . We postulate that the efficiency of the Southern Ocean carbon outgassing varied strongly with migrations of the STF, and that is in part accounted for the variability in p CO2 across M2. [ABSTRACT FROM AUTHOR]- Published
- 2024
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10. Late Cenozoic sea-surface-temperature evolution of the South Atlantic Ocean
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Hoem, Frida S., primary, López-Quirós, Adrián, additional, van de Lagemaat, Suzanna, additional, Etourneau, Johan, additional, Sicre, Marie-Alexandrine, additional, Escutia, Carlota, additional, Brinkhuis, Henk, additional, Peterse, Francien, additional, Sangiorgi, Francesca, additional, and Bijl, Peter K., additional
- Published
- 2023
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11. Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling
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Sauermilch, Isabel, Whittaker, Joanne M., Klocker, Andreas, Munday, David R., Hochmuth, Katharina, Bijl, Peter K., and LaCasce, Joseph H.
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- 2021
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12. Sedimentology of lower Pliocene to Upper Pleistocene diamictons from IODP Site U1358, Wilkes Land margin, and implications for East Antarctic Ice Sheet dynamics
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Orejola, Nadine, Passchier, Sandra, Brinkhuis, Hendrik, Escutia Dotti, Carlota, Klaus, Adam, Fehr, Annick, Williams, Trevor, Bendle, James AP, Bijl, Peter K, Bohaty, Steven M, Carr, Stephanie A, Dunbar, Robert B, Flores, Jose-Abel, Gonzalez, Jhon J, Hayden, Travis G, Iwai, Masao, Jimenez-Espejo, Francisco J, Katsuki, Kota, Kong, Gee Soo, McKay, Robert M, Nakai, Mutsumi, Olney, Matthew P, Pekar, Stephen F, Pross, Joerg, Riesselman, Christina, Roehl, Ursula, Sakai, Toyosaburo, Shrivastava, Prakash Kumar, Stickley, Catherine E, Sugisaki, Saiko, Tauxe, Lisa, Tuo, Shouting, van de Flierdt, Tina, Welsh, Kevin, Yamane, Masako, and Scientists, Iodp Expedition 318
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continental shelf ,geochemistry ,heavy minerals ,particle size ,provenance ,Marine Biology & Hydrobiology ,Environmental Sciences ,Biological Sciences ,Earth Sciences - Abstract
AbstractDuring the early Pliocene a dynamic marine-based ice sheet retreated from the Wilkes Land margin with periodic ice advances beyond Last Glacial Maximum position. A change in sand provenance is indicative of a more stable Mertz Glacier system during the Late Pleistocene. East Antarctic Ice Sheet (EAIS) dynamics were evaluated through the analysis of marine diamictons from Integrated Ocean Drilling Program (IODP) site U1358 on the Adélie Land continental shelf. The warmer than present conditions of the early Pliocene coupled with the site's proximity to the landward sloping Wilkes Subglacial Basin provided the rationale for the investigations at this site. Based on visual core descriptions, particle size distributions, and major and trace element ratios, we interpret the origin of lower Pliocene strata by intermittent glaciomarine sedimentation with open-marine conditions and extensive glacial advances to the outer shelf. Heavy mineral analyses show that sand-sized detritus in the lower Pliocene strata was sourced from local intermediate to high-grade metamorphic rocks near Mertz Glacier. In contrast, Pleistocene diamictons exhibit a larger contribution from a prehnite-pumpellyite greenschist facies suggesting supply via iceberg rafting from northern Victoria Land. From this sedimentological evidence, we postulate a shift from a dynamic EAIS margin in the early Pliocene to possible stabilization in the Pleistocene.
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- 2014
13. Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth
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Cook, Carys P, van de Flierdt, Tina, Williams, Trevor, Hemming, Sidney R, Iwai, Masao, Kobayashi, Munemasa, Jimenez-Espejo, Francisco J, Escutia, Carlota, González, Jhon Jairo, Khim, Boo-Keun, McKay, Robert M, Passchier, Sandra, Bohaty, Steven M, Riesselman, Christina R, Tauxe, Lisa, Sugisaki, Saiko, Galindo, Alberto Lopez, Patterson, Molly O, Sangiorgi, Francesca, Pierce, Elizabeth L, Brinkhuis, Henk, Klaus, Adam, Fehr, Annick, Bendle, James A. P, Bijl, Peter K, Carr, Stephanie A, Dunbar, Robert B, Flores, José Abel, Hayden, Travis G, Katsuki, Kota, Kong, Gee Soo, Nakai, Mutsumi, Olney, Matthew P, Pekar, Stephen F, Pross, Jörg, Röhl, Ursula, Sakai, Toyosaburo, Shrivastava, Prakash K, Stickley, Catherine E, Tuo, Shouting, Welsh, Kevin, and Yamane, Masako
- Published
- 2013
14. Lipid-biomarker-based sea surface temperature record offshore Tasmania over the last 23 million years
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Hou, Suning, primary, Lamprou, Foteini, additional, Hoem, Frida S., additional, Hadju, Mohammad Rizky Nanda, additional, Sangiorgi, Francesca, additional, Peterse, Francien, additional, and Bijl, Peter K., additional
- Published
- 2023
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15. DINOSTRAT version 2.0-GTS2020
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Bijl, Peter K.
- Abstract
Mesozoic–Cenozoic organic-walled dinoflagellate cyst (dinocyst) biostratigraphy is a crucial tool for relative and numerical age control in complex ancient sedimentary systems. However, stratigraphic ranges of dinocysts are found to be strongly diachronous geographically. A global compilation of state-of-the-art calibrated regional stratigraphic ranges could assist in quantifying regional differences and evaluate underlying causes. DINOSTRAT (Bijl, 2023a; Bijl, 2023b) is an open source, iterative, community-fed database intended to house all regional chronostratigraphic calibrations of dinocyst events DINOSTRAT version 2.0-GTS2020 includes >9,450 entries of first and last occurrences (collectively called “events”) of >2,040 dinocyst taxa, and their absolute ties are now updated to the chronostratigraphic timescale of Gradstein et al., 2020. Entries are derived from 211 publications and 209 sedimentary sections. DINOSTRAT interpolates paleolatitudes of regional dinocyst events, allowing evaluation of the paleolatitudinal variability of dinocyst event ages. DINOSTRAT allows for open accessibility and searchability, on region, age, and taxon. This paper presents a selection of the data in DINOSTRAT: (1) the (paleo)latitudinal spread and evolutionary history of modern dinocyst species; (2) the evolutionary patterns and paleolatitudinal spread of dinocyst (sub)families; (3) a selection of key dinocyst events which are particularly synchronous. Although several dinocysts show – at the resolution of their calibration – quasi-synchronous event ages, indeed many species have remarkable diachroneity. DINOSTRAT provides the data storage approach by which the community can now start to relate diachroneity to (1) inadequate tie to chronostratigraphic timescales; (2) complications in taxonomic concepts and (3) ocean connectivity and/or the affinities of taxa to environmental conditions.
- Published
- 2023
16. Lipid-biomarker-based sea surface temperature record offshore Tasmania over the last 23 million years
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Hou, Suning, Lamprou, Foteini, Hoem, Frida S., Hadju, Mohammad Rizky Nanda, Sangiorgi, Francesca, Peterse, Francien, Bijl, Peter K., Marine palynology and palaeoceanography, Organic geochemistry, and Marine Palynology
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Isoprenoid tetraether lipids ,Gdgt distributions ,Wilkes land ,Early eocene ,Global and Planetary Change ,Membrane-lipids ,Palaeontology ,Stratigraphy ,Southern-ocean ,Antarctic ice-sheet ,Water-column ,Organic-matter ,Particulate matter - Abstract
The Neogene (23.04-2.58 Ma) is characterised by progressive buildup of ice volume and climate cooling in the Antarctic and the Northern Hemisphere. Heat and moisture delivery to Antarctica is, to a large extent, regulated by the strength of meridional temperature gradients. However, the evolution of the Southern Ocean frontal systems remains scarcely studied in the Neogene. Here, we present the first long-term continuous sea surface temperature (SST) record of the subtropical front area in the Southern Ocean at Ocean Drilling Program (ODP) Site 1168 off western Tasmania. This site is, at present, located near the subtropical front (STF), as it was during the Neogene, despite a 10°northward tectonic drift of Tasmania. We analysed glycerol dialkyl glycerol tetraethers (GDGTs - on 433 samples) and alkenones (on 163 samples) and reconstructed the paleotemperature evolution using TEX86 and U37k′ as two independent quantitative proxies. Both proxies indicate that Site 1168 experienced a temperate ∼ 25 °C during the early Miocene (23-17 Ma), reaching ∼ 29 °C during the mid-Miocene climatic optimum. The stepwise ∼ 10°C cooling (20-10 °C) in the mid-to-late Miocene (12.5-5.0 Ma) is larger than that observed in records from lower and higher latitudes. From the Pliocene to modern (5.3-0 Ma), STF SST first plateaus at ∼ 15°C (3 Ma), then decreases to ∼ 6 °C (1.3 Ma), and eventually increases to the modern levels around ∼ 16 °C (0 Ma), with a higher variability of 5 compared to the Miocene. Our results imply that the latitudinal temperature gradient between the Pacific Equator and the STF during late Miocene cooling increased from 4 to 14°C. Meanwhile, the SST gradient between the STF and the Antarctic margin decreased due to amplified STF cooling compared to the Antarctic margin. This implies a narrowing SST gradient in the Neogene, with contraction of warm SSTs and northward expansion of subpolar conditions.
- Published
- 2023
17. Synchronous tropical and polar temperature evolution in the Eocene
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Cramwinckel, Margot J., Huber, Matthew, Kocken, Ilja J., Agnini, Claudia, Bijl, Peter K., Bohaty, Steven M., and Frieling, Joost
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Eocene Epoch ,Atmospheric temperature -- History ,Climate -- History ,Paleoclimatology -- Research ,Greenhouse gases ,Global temperature changes ,Climate models ,Oceans ,Carbon dioxide ,Climate change ,Air pollution ,Atmospheric carbon dioxide ,Proxy ,Ice caps ,Sediments (Geology) ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
Palaeoclimate reconstructions of periods with warm climates and high atmospheric CO.sub.2 concentrations are crucial for developing better projections of future climate change. Deep-ocean.sup.1,2 and high-latitude.sup.3 palaeotemperature proxies demonstrate that the Eocene epoch (56 to 34 million years ago) encompasses the warmest interval of the past 66 million years, followed by cooling towards the eventual establishment of ice caps on Antarctica. Eocene polar warmth is well established, so the main obstacle in quantifying the evolution of key climate parameters, such as global average temperature change and its polar amplification, is the lack of continuous high-quality tropical temperature reconstructions. Here we present a continuous Eocene equatorial sea surface temperature record, based on biomarker palaeothermometry applied on Atlantic Ocean sediments. We combine this record with the sparse existing data.sup.4-6 to construct a 26-million-year multi-proxy, multi-site stack of Eocene tropical climate evolution. We find that tropical and deep-ocean temperatures changed in parallel, under the influence of both long-term climate trends and short-lived events. This is consistent with the hypothesis that greenhouse gas forcing.sup.7,8, rather than changes in ocean circulation.sup.9,10, was the main driver of Eocene climate. Moreover, we observe a strong linear relationship between tropical and deep-ocean temperatures, which implies a constant polar amplification factor throughout the generally ice-free Eocene. Quantitative comparison with fully coupled climate model simulations indicates that global average temperatures were about 29, 26, 23 and 19 degrees Celsius in the early, early middle, late middle and late Eocene, respectively, compared to the preindustrial temperature of 14.4 degrees Celsius. Finally, combining proxy- and model-based temperature estimates with available CO.sub.2 reconstructions.sup.8 yields estimates of an Eocene Earth system sensitivity of 0.9 to 2.3 kelvin per watt per square metre at 68 per cent probability, consistent with the high end of previous estimates.sup.11.A 26-million-year record of equatorial sea surface temperatures reveals synchronous changes of tropical and polar temperatures during the Eocene epoch forced by variations in concentrations of atmospheric carbon dioxide, with a constant degree of polar amplification., Author(s): Margot J. Cramwinckel [sup.1] , Matthew Huber [sup.2] , Ilja J. Kocken [sup.1] , Claudia Agnini [sup.3] , Peter K. Bijl [sup.1] , Steven M. Bohaty [sup.4] , Joost [...]
- Published
- 2018
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18. Deoxygenation and organic carbon sequestration in the Tethyan realm associated with the middle Eocene climatic optimum
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Cramwinckel, Margot J., van der Ploeg, Robin, van Helmond, Niels A.G.M., Waarlo, Niels, Agnini, Claudia, Bijl, Peter K., van der Boon, Annique, Brinkhuis, Henk, Frieling, Joost, Krijgsman, Wout, Mather, Tamsin A., Middelburg, Jack J., Peterse, Francien, Slomp, Caroline P., Sluijs, Appy, Marine Palynology, Stratigraphy and paleontology, Marine palynology and palaeoceanography, Geochemistry, Paleomagnetism, Organic geochemistry, Marine Palynology, Stratigraphy and paleontology, Marine palynology and palaeoceanography, Geochemistry, Paleomagnetism, and Organic geochemistry
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Atmospheric mercury ,Dinoflagellate cysts ,Glycerol ether lipids ,Thermal maximum ,Proxy data ,Southwest pacific ,Water-column ,Geology ,Biomarker paleothermometry ,Bacterial gmgts ,North caucasus - Abstract
The middle Eocene climatic optimum (ca. 40 Ma) stands out as a transient global warming phase of ∼400 k.y. duration that interrupted long-termEocene cooling; it has been associated with a rise in atmospheric CO 2 concentrations that has been linked to a flare-up in Arabia-Eurasia continental arc volcanism. Increased organic carbon burial in the Tethys Ocean has been proposed as a carbon sequestration mechanism to bring the middle Eocene climatic optimum to an end. To further test these hypotheses, we assessed the sedimentary and geochemical expression of the middle Eocene climatic optimum in the northern Peri-Tethys, specifically, the organic-rich Kuma Formation of the Belaya River section, located on the edge of the Scythian Platform in the North Caucasus, Russia. We constructed an age-depth model using nannofossil chronobiostratigraphy. Throughout the studied middle Eocene interval (41.2−39.9 Ma), we documented sea-surface temperatures of 32−36 °C based on the tetraether index of tetraethers consisting of 86 carbons (TEX86), depending on proxy calibration, and during the early middle Eocene climatic optimum, we observed sea-surface warming of 2−3 °C. Despite the proximity of the section to the Arabia-Eurasia volcanic arc, the hypothesized source of volcanic CO2, we found no evidence for enhanced regional volcanism in sedimentary mercury concentrations. Sedimentary trace-element concentrations and iron speciation indicate reducing bottom waters throughout the middle Eocene, but the most reducing, even euxinic, conditions were reached during late middle Eocene climatic optimum cooling. This apparent regional decoupling between ocean warming and deoxygenation hints at a role for regional tectonics in causing basin restriction and anoxia. Associated excess organic carbon burial, extrapolated to the entire regional Kuma Formation, may have been ∼8.1 Tg C yr−1, comprising ∼450 Pg C over this ∼55 k.y. interval. Combined with evidence for enhanced organic carbon drawdown in the western Peri-Tethys, this supports a quantitatively significant role for the basin in the termination of the middle Eocene climatic optimum by acting as a large organic carbon sink, and these results collectively illustrate that the closing Tethys Ocean might have affected global Paleogene climate. Moreover, this study highlights the importance of the interplay between global climate and regional oceanic gateway evolution in determining local climate and oceanographic change.
- Published
- 2023
19. Polar amplification of orbital-scale climate variability in the early Eocene greenhouse world.
- Author
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Fokkema, Chris D., Agterhuis, Tobias, Gerritsma, Danielle, de Goeij, Myrthe, Xiaoqing Liu, de Regt, Pauline, Rice, Addison, Vennema, Laurens, Agnini, Claudia, Bijl, Peter K., Frieling, Joost, Huber, Matthew, Peterse, Francien, and Sluijs, Appy
- Abstract
Climate variability is typically amplified towards polar regions. The underlying causes, notably albedo and humidity changes, are challenging to accurately quantify with observations or models, hampering projections of future polar amplification. Polar amplification reconstructions from the ice-free early Eocene (~56-48 million years ago) can exclude ice albedo effects, but the required tropical temperature records for resolving timescales shorter than multi-million years are lacking. Here, we reconstruct early Eocene tropical sea surface temperature variability by presenting an up to ~4 kyr-resolution biomarker-based temperature record from Ocean Drilling Program Site 959, located in the tropical Atlantic Ocean. This record shows warming across multiple orbitally paced carbon cycle perturbations, coeval with high-latitude-derived deep-ocean bottom waters, showing that these events represent transient global warming events (hyperthermals). This implies that orbital forcing caused global temperature variability through carbon cycle feedbacks. Importantly, deep-ocean temperature variability was amplified by a factor 1.7-2.3 compared to the tropical surface ocean, corroborating available long-term estimates. This implies that fast atmospheric feedback processes controlled meridional temperature gradients on multi-million year, as well as orbital timescales during the early Eocene. Our combined records have several other implications. First, our amplification factor is somewhat larger than the same metric in fully-coupled simulations of the early Eocene (1.1-1.3), suggesting that models slightly underestimate the non-ice related -- notably hydrological -- feedbacks that cause polar amplification of climate change. Second, even outside the hyperthermals, we find synchronous eccentricity-forced temperature variability in the tropics and deep ocean that represent global mean sea surface temperature variability of up to 0.7 °C, and requires significant variability in atmospheric pCO2. We hypothesize that the responsible carbon cycle feedbacks that are independent of ice, snow and frost-related processes might play an important role in Phanerozoic orbital-scale climate variability throughout geological time, including Pleistocene glacial-interglacial climate variability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Palsys.org: an open-access taxonomic and stratigraphic database of organic-walled dinoflagellate cysts.
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Bijl, Peter K. and Brinkhuis, Henk
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DINOFLAGELLATE cysts ,DATABASES ,IMAGE databases ,QUALITY control ,MICROPALEONTOLOGY - Abstract
It is with great pleasure that we introduce palsys.org (https://palsys.org/genus/ , last access: 8 December 2023), a fully open-access taxonomic, stratigraphic and image database of organic-walled dinoflagellate cysts. Palsys.org started as the in-house database of the Laboratory of Palaeobotany and Palynology (LPP) Foundation over 30 years ago. It is now owned by Utrecht University and has been expanded and transformed into a public online platform for use in research and education. Palsys.org includes the taxonomic descriptions of genera and species of organic walled dinoflagellate cysts, from the (often translated) literature, and emendations and synonymy, mainly following Williams et al. (2017) and the stratigraphic calibrations from DINOSTRAT (Bijl, 2022), and has around 25 000 images of species. Here, in this launch paper, we explain the history of the database, present its current functionalities and explain our set-up of the data quality control. We call upon the community to help us keep palsys.org up to date and complete by, for example, by sending additional information, imagery and feedback in general through the platform. Palsys.org brings dinoflagellate micropaleontology in line with the open-science principles of modern academia. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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21. Maastrichtian–Rupelian paleoclimates in the southwest Pacific – a critical re-evaluation of biomarker paleothermometry and dinoflagellate cyst paleoecology at Ocean Drilling Program Site 1172
- Author
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Bijl, Peter K., Frieling, Joost, Cramwinckel, Margot J., Boschman, Christine, Sluijs, Appy, Peterse, Francien, Marine palynology and palaeoceanography, Stratigraphy and paleontology, Organic geochemistry, and Marine Palynology
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geography ,Global and Planetary Change ,Plateau ,geography.geographical_feature_category ,Stratigraphy ,Palaeontology ,Holocene climatic optimum ,Paleontology ,Subsidence (atmosphere) ,Environmental protection ,Environmental pollution ,Sedimentary depositional environment ,Environmental sciences ,Sea surface temperature ,Oceanography ,TD172-193.5 ,TD169-171.8 ,Paleoecology ,Dinocyst ,Sedimentary rock ,GE1-350 ,Geology - Abstract
Sea surface temperature (SST) reconstructions based on isoprenoid glycerol dialkyl glycerol tetraether (isoGDGT) distributions from the Eocene southwest (SW) Pacific Ocean are unequivocally warmer than can be reconciled with state-of-the-art fully coupled climate models. However, the SST signal preserved in sedimentary archives can be affected by contributions of additional isoGDGT sources. Methods now exist to identify and possibly correct for overprinting effects on the isoGDGT distribution in marine sediments. Here, we use the current proxy insights to (re-)assess the reliability of the isoGDGT-based SST signal in 69 newly analyzed and 242 reanalyzed sediments at Ocean Drilling Program (ODP) Site 1172 (East Tasman Plateau, Australia) following state-of-the-art chromatographic techniques. We compare our results with paleoenvironmental and paleoclimatologic reconstructions based on dinoflagellate cysts. The resulting ∼ 130 kyr resolution Maastrichtian–Oligocene SST record based on the TetraEther indeX of tetraethers with 86 carbon atoms (TEX86) confirms previous conclusions of anomalous warmth in the early Eocene SW Pacific and remarkably cool conditions during the mid-Paleocene. Dinocyst diversity and assemblages show a strong response to the local SST evolution, supporting the robustness of the TEX86 record. Soil-derived branched GDGTs stored in the same sediments are used to reconstruct mean annual air temperature (MAAT) of the nearby land using the Methylation index of Branched Tetraethers with 5-methyl bonds (MBT'5me) proxy. MAAT is consistently lower than SST during the early Eocene, independent of the calibration chosen. General trends in SST and MAAT are similar, except for (1) an enigmatic absence of MAAT rise during the Paleocene–Eocene Thermal Maximum and Middle Eocene Climatic Optimum, and (2) a subdued middle–late Eocene MAAT cooling relative to SST. Both dinocysts and GDGT signals suggest a mid-shelf depositional environment with strong river runoff during the Paleocene–early Eocene progressively becoming more marine thereafter. This trend reflects gradual subsidence and more pronounced wet/dry seasons in the northward-drifting Australian hinterland, which may also explain the subdued middle Eocene MAAT cooling relative to that of SST. The overall correlation between dinocyst assemblages, marine biodiversity and SST changes suggests that temperature exerted a strong influence on the surface-water ecosystem. Finally, we find support for a potential temperature control on compositional changes of branched glycerol monoalkyl glycerol tetraethers (brGMGTs) in marine sediments. It is encouraging that a critical evaluation of the GDGT signals confirms that most of the generated data are reliable. However, this also implies that the high TEX86-based SSTs for the Eocene SW Pacific and the systematic offset between absolute TEX86-based SST and MBT'5me-based MAAT estimates remain without definitive explanation.
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- 2021
22. Eocene cooling linked to early flow across the Tasmanian Gateway
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Bijl, Peter K., Bendle, James A. P., Bohaty, Steven M., Pross, Jörg, Schouten, Stefan, Tauxe, Lisa, Stickley, Catherine E., McKay, Robert M., Röhl, Ursula, Olney, Matthew, Sluijs, Appy, Escutia, Carlota, and Brinkhuis, Henk
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- 2013
23. Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region were controlled by changes in ocean currents and pCO2
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Amoo, Michael, Salzmann, Ulrich, Pound, Matthew J., Thompson, Nick, Bijl, Peter K., Marine palynology and palaeoceanography, and Marine Palynology
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Global and Planetary Change ,Stratigraphy ,Palaeontology - Abstract
Considered one of the most significant climate reorganizations of the Cenozoic period, the Eocene-Oligocene Transition (EOT; ca. 34.44-33.65) is characterized by global cooling and the first major glacial advance on Antarctica. In the southern high latitudes, the EOT cooling is primarily recorded in the marine realm, and its extent and effect on the terrestrial climate and vegetation are poorly documented. Here, we present new, well-dated, continuous, high-resolution palynological (sporomorph) data and quantitative sporomorph-based climate estimates recovered from the East Tasman Plateau (ODP Site 1172) to reconstruct climate and vegetation dynamics from the late Eocene (37.97gMa) to the early Oligocene (33.06gMa). Our results indicate three major climate transitions and four vegetation communities occupying Tasmania under different precipitation and temperature regimes: (i) a warm-temperate Nothofagus-Podocarpaceae-dominated rainforest with paratropical elements from 37.97 to 37.52gMa; (ii) a cool-temperate Nothofagus-dominated rainforest with secondary Podocarpaceae rapidly expanding and taking over regions previously occupied by the warmer taxa between 37.306 and 35.60gMa; (iii) fluctuation between warm-temperate-paratropical taxa and cool temperate forest from 35.50 to 34.49gMa, followed by a cool phase across the EOT (34.30-33.82gMa); and (iv) a post-EOT (earliest Oligocene) recovery characterized by a warm-temperate forest association from 33.55 to 33.06gMa. Coincident with changes in the stratification of water masses and sequestration of carbon from surface water in the Southern Ocean, our sporomorph-based temperature estimates between 37.52 and 35.60gMa (phase ii) showed 2-3gg C terrestrial cooling. The unusual fluctuation between warm and cold temperate forest between 35.50 to 34.59gMa is suggested to be linked to the initial deepening of the Tasmanian Gateway, allowing eastern Tasmania to come under the influence of warm water associated with the proto-Leeuwin Current (PLC). Further to the above, our terrestrial data show the mean annual temperature declining by about 2gg C across the EOT before recovering in the earliest Oligocene. This phenomenon is synchronous with regional and global cooling during the EOT and linked to declining pCO2. However, the earliest Oligocene climate rebound along eastern Tasmania is linked to a transient recovery of atmospheric pCO2 and sustained deepening of the Tasmanian Gateway, promoting PLC throughflow. The three main climate transitional events across the studied interval (late Eocene-earliest Oligocene) in the Tasmanian Gateway region suggest that changes in ocean circulation due to accelerated deepening of the Tasmanian Gateway may not have been solely responsible for the changes in terrestrial climate and vegetation dynamics; a series of regional and global events, including a change in the stratification of water masses, sequestration of carbon from surface waters, and changes in pCO2, may have also played vital roles.
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- 2022
24. Enhanced Terrestrial Carbon Export From East Antarctica During the Early Eocene
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Inglis, Gordon N., Toney, Jaime L., Zhu, Jiang, Poulsen, Christopher J., Röhl, Ursula, Jamieson, Stewart S.R., Pross, Jörg, Cramwinckel, Margot J., Krishnan, Srinath, Pagani, Mark, Bijl, Peter K., Bendle, James, Marine palynology and palaeoceanography, Marine Palynology, Marine palynology and palaeoceanography, and Marine Palynology
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lipids ,Atmospheric Science ,Palaeontology ,greenhouse ,Paleontology ,biomarkers ,DeepMIP ,leaf wax ,Oceanography ,cenozoic - Abstract
Terrestrial organic carbon (TerrOC) acts as an important CO2 sink when transported via rivers to the ocean and sequestered in coastal marine sediments. This mechanism might help to modulate atmospheric CO2 levels over short- and long timescales (103 to 106 years), but its importance during past warm climates remains unknown. Here we use terrestrial biomarkers preserved in coastal marine sediment samples from Wilkes Land, East Antarctica (~67°S) to quantify TerrOC burial during the early Eocene (~54.4 to 51.5 Ma). Terrestrial biomarker distributions indicate the delivery of plant-, soil- and peat-derived organic carbon (OC) into the marine realm. Mass accumulation rates of plant- (long-chain n-alkane) and soil-derived (hopane) biomarkers dramatically increase between the earliest Eocene (~54 Ma) and the early Eocene Climatic Optimum (EECO; ~53 Ma). This coincides with increased OC mass accumulation rates and indicates enhanced TerrOC burial during the EECO. Leaf wax δ 2H values indicate that the EECO was characterised by wetter conditions relative to the earliest Eocene, suggesting that hydroclimate exerts a first-order control on TerrOC export. Our results indicate that TerrOC burial in coastal marine sediments UOB Open could have acted as an important negative feedback mechanism during the early Eocene, but also during other warm climate intervals.
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- 2022
25. Expedition 392 Preliminary Report Agulhas Plateau Cretaceous Climate: drilling the Agulhas Plateau and Transkei Basin to reconstruct the Cretaceous–Paleogene tectonic and climatic evolution of the Southern Ocean basin, 5 February–7 April 2022
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Uenzelmann-Neben, Gabriele, Bohaty, Steven M., Childress, Laurel B., Archontikis, Odysseas A., Batenburg, Sietske J., Bijl, Peter K., Burkett, Ashley M., Chanda, Pratyusha, Coenen, Jason J., Dallanave, Edoardo, Davidson, Peter C., Doiron, Kelsey E., Geldmacher, Jörg, Gürer, Derya, Haynes, Shannon J., Herrle, Jens O., Ichiyama, Yuji, Jana, Debadrita, Jones, Matthew M., Kato, Chie, Kulhanek, Denise K., Li, Juan, Liu, Jia, McManus, James, Minakov, Alexander N., Penman, Donald E., Sprain, Courtney J., Tessin, Allyson C., Wagner, Thomas, and Westerhold, Thomas
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- 2022
26. Agulhas Plateau Cretaceous Climate: drilling the Agulhas Plateau and Transkei Basin to reconstruct the Cretaceous–Paleogene tectonic and climatic evolution of the Southern Ocean basin
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Uenzelmann-Neben, Gabriele, Bohaty, Steven M., Childress, Laurel B., Archontikis, Odysseas A., Batenburg, Sietske J., Bijl, Peter K., Burkett, Ashley M., Chanda, Pratyusha, Coenen, Jason J., Dallanave, Edoardo, Davidson, Peter C., Doiron, Kelsey E., Geldmacher, Jörg, Gürer, Derya, Haynes, Shannon J., Herrle, Jens O., Ichiyama, Yuji, Jana, Debadrita, Jones, Matthew M., Kato, Chie, Kulhanek, Denise K., Li, Juan, Liu, Jia, McManus, James, Yakutchik, Maryalice, Cawthra, Hayley C., Minakov, Alexander, Penman, Donald E., Sprain, Courtney J., Tessin, Allyson C., Wagner, Thomas, and Westerhold, Thomas
- Abstract
During International Ocean Discovery Program Expedition 392, three sites were drilled on the Agulhas Plateau and one site was drilled in the Transkei Basin in the Southwest Indian Ocean. This region was positioned at paleolatitudes of ~53°–61°S during the Late Cretaceous (van Hinsbergen et al., 2015) (100–66 Ma) and within the new and evolving gateway between the South Atlantic, Southern Ocean, and southern Indian Ocean basins. Recovery of basement rocks and sedimentary sequences from the Agulhas Plateau sites and a thick sedimentary sequence in the Transkei Basin provides a wealth of new data to (1) determine the nature and origin of the Agulhas Plateau; (2) significantly advance the understanding of how Cretaceous temperatures, ocean circulation, and sedimentation patterns evolved as CO2 levels rose and fell and the breakup of Gondwana progressed; (3) document long-term paleoceanographic variability through the Late Cretaceous and Paleogene; and (4) investigate geochemical interactions between igneous rocks, sediments, and pore waters through the life cycle of a large igneous province (LIP). Importantly, postcruise analysis of Expedition 392 drill cores will allow testing of competing hypotheses concerning Agulhas Plateau LIP formation and the role of deep ocean circulation changes through southern gateways in controlling Late Cretaceous–early Paleogene climate evolution.
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- 2022
27. Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region were controlled by changes in ocean currents and <i>p</i>CO<sub>2</sub>
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Amoo, Michael, primary, Salzmann, Ulrich, additional, Pound, Matthew J., additional, Thompson, Nick, additional, and Bijl, Peter K., additional
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- 2022
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28. Sedimentary microplankton distributions are shaped by oceanographically connected areas
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Nooteboom, Peter D., primary, Bijl, Peter K., additional, Kehl, Christian, additional, van Sebille, Erik, additional, Ziegler, Martin, additional, von der Heydt, Anna S., additional, and Dijkstra, Henk A., additional
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- 2022
- Full Text
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29. DINOSTRAT: a global database of the stratigraphic and paleolatitudinal distribution of Mesozoic–Cenozoic organic-walled dinoflagellate cysts
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Bijl, Peter K., primary
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- 2022
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- View/download PDF
30. Vegetation change across the Drake Passage region linked to late Eocene cooling and glacial disturbance after the Eocene–Oligocene transition
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Thompson, Nick, primary, Salzmann, Ulrich, additional, López-Quirós, Adrián, additional, Bijl, Peter K., additional, Hoem, Frida S., additional, Etourneau, Johan, additional, Sicre, Marie-Alexandrine, additional, Roignant, Sabine, additional, Hocking, Emma, additional, Amoo, Michael, additional, and Escutia, Carlota, additional
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- 2022
- Full Text
- View/download PDF
31. Surface-circulation change in the southwest Pacific Ocean across the Middle Eocene Climatic Optimum: inferences from dinoflagellate cysts and biomarker paleothermometry
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Cramwinckel, Margot J., Woelders, Lineke, Huurdeman, Emiel P., Peterse, Francien, Gallagher, Stephen J., Pross, Jorg, Burgess, Catherine E., Reichart, Gert Jan, Sluijs, Appy, Bijl, Peter K., Marine palynology and palaeoceanography, Organic geochemistry, Stratigraphy and paleontology, Marine Palynology, Marine palynology and palaeoceanography, Organic geochemistry, Stratigraphy and paleontology, and Marine Palynology
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lcsh:GE1-350 ,Global and Planetary Change ,010504 meteorology & atmospheric sciences ,Stratigraphy ,Palaeontology ,lcsh:Environmental protection ,Paleontology ,010502 geochemistry & geophysics ,01 natural sciences ,lcsh:Environmental pollution ,lcsh:TD172-193.5 ,lcsh:TD169-171.8 ,lcsh:Environmental sciences ,0105 earth and related environmental sciences - Abstract
Global climate cooled from the early Eocene hothouse (∼52–50 Ma) to the latest Eocene (∼34 Ma). At the same time, the tectonic evolution of the Southern Ocean was characterized by the opening and deepening of circum-Antarctic gateways, which affected both surface- and deep-ocean circulation. The Tasmanian Gateway played a key role in regulating ocean throughflow between Australia and Antarctica. Southern Ocean surface currents through and around the Tasmanian Gateway have left recognizable tracers in the spatiotemporal distribution of plankton fossils, including organic-walled dinoflagellate cysts. This spatiotemporal distribution depends on both the physicochemical properties of the water masses and the path of surface-ocean currents. The extent to which climate and tectonics have influenced the distribution and composition of surface currents and thus fossil assemblages has, however, remained unclear. In particular, the contribution of climate change to oceanographic changes, superimposed on long-term and gradual changes induced by tectonics, is still poorly understood. To disentangle the effects of tectonism and climate in the southwest Pacific Ocean, we target a climatic deviation from the long-term Eocene cooling trend: the Middle Eocene Climatic Optimum (MECO; ∼40 Ma). This 500 kyr phase of global warming was unrelated to regional tectonism, and thus provides a test case to investigate the ocean's physicochemical response to climate change alone. We reconstruct changes in surface-water circulation and temperature in and around the Tasmanian Gateway during the MECO through new palynological and organic geochemical records from the central Tasmanian Gateway (Ocean Drilling Program Site 1170), the Otway Basin (southeastern Australia), and the Hampden Beach section (New Zealand). Our results confirm that dinocyst communities track specific surface-ocean currents, yet the variability within the communities can be driven by superimposed temperature change. Together with published results from the east of the Tasmanian Gateway, our new results suggest a shift in surface-ocean circulation during the peak of MECO warmth. Simultaneous with high sea-surface temperatures in the Tasmanian Gateway area, pollen assemblages indicate warm temperate rainforests with paratropical elements along the southeastern margin of Australia. Finally, based on new age constraints, we suggest that a regional southeast Australian transgression might have been coincident with the MECO.
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- 2020
32. Transient Middle Eocene Atmospheric CO₂ and Temperature Variations
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Bijl, Peter K., Houben, Alexander J. P., Schouten, Stefan, Bohaty, Steven M., Sluijs, Appy, Reichart, Gert-Jan, Damsté, Jaap S. Sinninghe, and Brinkhuis, Henk
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- 2010
33. Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO2
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Amoo, Michael, Salzmann, Ulrich, Pound, Matthew J., Thompson, Nick, and Bijl, Peter K.
- Subjects
F700 ,F800 - Abstract
Considered as one of the most significant climate reorganisations of the Cenozoic period, the Eocene-Oligocene Transition (EOT; ca. 34.44–33.65) is characterised by global cooling and the first major glacial advance on Antarctica. While in the southern high-latitudes, the EOT cooling is primarily recorded in the marine realm, the extent and effect on terrestrial climate and vegetation is poorly documented. Here, we present a new, well-dated, continuous, high-resolution palynological (sporomorph) data and quantitative sporomorph-based climate estimates recovered from the East Tasman Plateau (ODP Site 1172) to reconstruct climate and vegetation dynamics from the late Eocene (37.97 Ma) to early Oligocene (33.06 Ma). Our results indicate three major climate transitions and four vegetation communities occupying Tasmania under different precipitation and temperature regimes: (i) a warm-temperate Nothofagus-Podocarpaceae dominated rainforest with paratropical elements from 37.97–37.52 Ma; (ii) cool-temperate Nothofagus dominated rainforest with secondary Podocarpaceae rapidly expanding and taking over regions previously occupied by the warmer taxa between 37.306–35.60 Ma; (iii) fluctuation between warm temperate – paratropical taxa and cool temperate forest from 35.50–34.49 Ma, followed by a cool phase across the EOT (34.30–33.82 Ma); (iv) post-EOT (earliest Oligocene) recovery characterised by a warm-temperate forest association from 33.55–33.06 Ma. Coincident with changes in stratification of water masses and sequestration of carbon from surface water in the Southern Ocean, our sporomorph-based temperature estimates between 37.52 Ma and 35.60 Ma (phase ii) showed 2–3 °C terrestrial cooling. The unusual fluctuation between warm and cold temperate forest between 35.50 to 34.59 Ma is suggested to be linked to the initial deepening of the Tasmanian Gateway allowing eastern Tasmania to come under the influence of warm water associated with the proto-Leeuwin Current (PLC). Further to the above, our terrestrial data show mean annual temperature declining by about 2 °C across the EOT before recovering in the earliest Oligocene. This phenomenon is synchronous with regional and global cooling during the EOT and linked to declining pCO2. However, the earliest Oligocene climate rebound along eastern Tasmania is linked to transient recovery of atmospheric pCO2 and sustained deepening of the Tasmanian Gateway, promoting PLC throughflow. The three main climate transitional events across the studied interval (late Eocene–earliest Oligocene) in the Tasmanian Gateway region suggest that changes in ocean circulation due to accelerated deepening of the Tasmanian Gateway may not have been solely responsible for the changes in terrestrial climate and vegetation dynamics, but a series of regional and global events, including a change in stratification of water masses, sequestration of carbon from surface waters, and changes in pCO2 may have played vital roles.
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- 2021
34. Late Eocene–early Miocene evolution of the southern Australian subtropical front: a marine palynological approach
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Hoem, Frida S., primary, Sauermilch, Isabel, additional, Hou, Suning, additional, Brinkhuis, Henk, additional, Sangiorgi, Francesca, additional, and Bijl, Peter K., additional
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- 2021
- Full Text
- View/download PDF
35. Vegetation change across the Drake Passage region linked to late Eocene cooling and glacial disturbance after the Eocene–Oligocene Transition
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Thompson, Nick, Salzmann, Ulrich, López-Quirós, Adrián, Bijl, Peter K., Hoem, Frida S., Etourneau, Johan, Sicre, Marie Alexandrine, Roignant, Sabine, Hocking, Emma, Amoo, Michael, Escutia, Carlota, Marine palynology and palaeoceanography, Marine Palynology, University of Northumbria at Newcastle [United Kingdom], Aarhus University [Aarhus], Instituto Andaluz de Ciencias de la Tierra (IACT), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad de Granada (UGR), Department of Earth Sciences [Utrecht], Utrecht University [Utrecht], Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Newcastle University [Newcastle], Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad de Granada = University of Granada (UGR), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Marine palynology and palaeoceanography, and Marine Palynology
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Disturbance (geology) ,Stratigraphy ,[SDE.MCG]Environmental Sciences/Global Changes ,NEW-ZEALAND ,F700 ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,F800 ,Structural basin ,Environmental protection ,F900 ,Environmental pollution ,SEYMOUR ISLAND ,CONTINENTAL-SHELF ,Paleontology ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,GEOCHEMICAL PROXIES ,TD169-171.8 ,CARBON-ISOTOPE ANALYSES ,Paleoclimatology ,HOLOCENE CLIMATE EVOLUTION ,GE1-350 ,14. Life underwater ,Mesozoic ,Glacial period ,MIOCENE SEDIMENTS ,N-ALKANE DISTRIBUTIONS ,Global and Planetary Change ,EAST ANTARCTICA ,Palaeontology ,Vegetation ,15. Life on land ,Environmental sciences ,ORGANIC-MATTER ,TD172-193.5 ,13. Climate action ,[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology ,[SDE]Environmental Sciences ,Period (geology) ,Global cooling ,Geology - Abstract
Nick Thompson received funding from the Natural Environment Research Council from a NERC-funded Doctoral Training Partnership ONE Planet (grant no. NE/S007512/1). Funding for this research was also provided by the Spanish Ministry of Science and Innovation (grant nos. CTM2014-60451-C2- 1/2-P and CTM2017-89711-C2-1/2-P) cofunded by the European Union through FEDER funds. Peter K. Bijl received funding from the European Research Council (OceaNice (grant no. 802835))., This work used Deep Sea Drilling Project archived samples provided by the International Ocean Discovery Program (IODP). We thank the staff at the Gulf Coast core repository (GCR) for assistance in ODP Leg 113 core handling and shipping. We thank CNRS for the salary support of MAS, The role and climatic impact of the opening of the Drake Passage and how it affected both marine and terrestrial environments across the Eocene-Oligocene transition (EOT ∼34 Ma) period remains poorly understood. Here we present new terrestrial palynomorph data compared with recently compiled lipid biomarker (n-alkane) data from Ocean Drilling Program (ODP) Leg 113, Site 696, drilled on the margin of the South Orkney Microcontinent (SOM) in the Weddell Sea, to investigate changes in terrestrial environments and palaeoclimate across the late Eocene and early Oligocene (∼37.6-32.2 Ma). Early late Eocene floras and sporomorph-based climate estimates reveal Nothofagus-dominated forests growing under wet temperate conditions, with mean annual temperature (MAT) and precipitation (MAP) around 12 C and 1802 mm respectively. A phase of latest Eocene terrestrial cooling at 35.5 Ma reveals a decrease in MAT by around 1.4 C possibly linked to the opening of the Powell Basin. This is followed by an increase in reworked Mesozoic sporomorphs together with sedimentological evidence indicating ice expansion to coastal and shelf areas approximately 34.1 Myr ago. However, major changes to the terrestrial vegetation at Site 696 did not take place until the early Oligocene, where there is a distinct expansion of gymnosperms and cryptogams accompanied by a rapid increase in taxon diversity and a shift in terrestrial biomarkers reflecting a change from temperate forests to cool temperate forests following 33.5 Ma. This surprising expansion of gymnosperms and cryptogams is suggested to be linked to environmental disturbance caused by repeat glacial expansion and retreat, which facilitated the proliferation of conifers and ferns. The timing of glacial onset at Site 696 is linked to the global cooling at the EOT, yet the latest Eocene regional cooling cannot directly be linked to the observed vegetation changes. Therefore, our vegetation record provides further evidence that the opening of the Drake Passage and Antarctic glaciation were not contemporaneous, although stepwise cooling in response to the opening of ocean gateways surrounding the Antarctic continent may have occurred prior to the EOT., NERC-funded NE/S007512/1, Natural Environment Research Council, European Commission, European Research Council 802835, Ministerio de Ciencia e Innovación CTM2014-60451-C2- 1/2-P, CTM2017-89711-C2-1/2-P, European Regional Development Fund
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- 2021
36. Lipid biomarker-based sea (sub)surface temperature record offshore Tasmania over the last 23 million years.
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Suning Hou, Lamprou, Foteini, Hoem, Frida S., Hadju, Mohammad Rizky Nanda, Sangiorgi, Francesca, Peterse, Francien, and Bijl, Peter K.
- Abstract
The Neogene (23.04-2.58 Ma) is characterized by progressive buildup of Antarctic and Northern Hemisphere ice volume and climate cooling. Heat/moisture delivery to Antarctica is to a large extent regulated by the strength of meridional temperature gradients. However, the evolution of the Southern Ocean frontal systems remains scarcely studied in the Neogene. Here we present the first long-term continuous sea (sub)surface temperature (SST) record of the subtropical front area in the Southern Ocean at Ocean Drilling Program (ODP) Site 1168 off western Tasmania. This site is at present located near the subtropical front (STF), as it was during the Neogene, despite a 10 degree northward tectonic drift of Tasmania during the Neogene. We analyzed glycerol dialkyl glycerol tetraethers (GDGTs, on 433 samples) and alkenones (on 163 samples) and reconstructed the paleotemperature evolution using TEX
86 and Uk '37 as two independent quantitative proxies. Both proxies indicate that Site 1168 experienced a temperate ~25°C during early Miocene (23-17 Ma), reaching ~29 °C during the mid-Miocene Climatic Optimum. The stepwise ~10°C cooling (20-10°C) in the mid-to-late Miocene (12.5-5.0 Ma) is larger than observed in records from lower and higher latitudes. From the Pliocene to modern (5.3-0 Ma), STF SST first plateaus at ~15°C (3 Ma), then decreases to ~6°C (1.3 Ma), and eventually increases to the modern levels around ~16 °C (0 Ma), with a higher variability of 5 degrees compared to the Miocene. Our results imply that the latitudinal temperature gradient between the Pacific equator and STF during late Miocene cooling increased from 4°C to 14°C. Meanwhile, the SST gradient between the STF and the Antarctic margin decreased due to amplified STF cooling compared to the Antarctic Margin. This implies a narrowing SST gradient in the Neogene, with contraction of warm SSTs and northward expansion of subpolar conditions. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
37. Campanian-Eocene dinoflagellate cyst biostratigraphy in the Southern Andean foreland basin: Implications for Drake Passage throughflow
- Author
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Bijl, Peter K., Guerstein, G. Raquel, Jaimes, Edgar A.Sanmiguel, Sluijs, Appy, Casadio, Silvio, Valencia, Víctor, Amenábar, Cecilia R., Encinas, Alfonso, Marine palynology and palaeoceanography, Marine Palynology, Marine palynology and palaeoceanography, and Marine Palynology
- Subjects
010506 paleontology ,Stratigraphy ,Biostratigraphy ,010502 geochemistry & geophysics ,01 natural sciences ,Paleontology ,Paleoceanography ,Ocean gyre ,Geochemistry and Petrology ,Taverne ,Foreland basin ,Ciencias Exactas y Naturales ,0105 earth and related environmental sciences ,geography ,geography.geographical_feature_category ,Andean orogeny ,Subduction ,Drake passage ,Radiometric dating ,Dinoflagellate cysts ,Palaeontology ,Geology ,Sedimentary rock ,Paleogene ,Cenozoic ,Endemism - Abstract
Fil: Bijl, Peter. Department of Earth Sciences, Laboratory of Palaeobotany and Palynology, Utrecht University. The Netherlands. Fil: Guerstein, Raquel. Departamento de Geología, Universidad Nacional del Sur-Instituto Geológico del Sur, CONICET. Argentina. Fil: Sanmiguel Jaimes, Edgar. Universidad Andres Bello, Facultad de Ingenieria, Autopista Concepción-Talcahuano. Chile. Fil: Sluijs, Appy. Department of Earth Sciences, Laboratory of Palaeobotany and Palynology, Utrecht University. The Netherlands. Fil: Casadio, Silvio. Universidad Nacional de Río Negro, Instituto de Investigación en Paleobiología y Geología. Río Negro, Argentina. Fil: Valencia, Víctor. School of the Environment, Washington State University. USA. Fil: Amenábar, Cecilia. Instituto Antártico Argentino-Instituto de Estudios Andinos Don Pablo Groeber-CONICET-Dpto. Ciencias Geológicas, Universidad de Buenos Aires. Argentina. Fil: Encinas, Alfonso. Departamento de Ciencias de la Tierra, Facultad de Ciencias Químicas, Universidad de Concepción. Chile. The tectonic opening of the Tasmanian Gateway and Drake Passage represented crucial geographic requirements for the Cenozoic development of the Antarctic Circumpolar Current (ACC). Particularly the tectonic complexity of Drake Passage has hampered the exact dating of the opening and deepening phases, and the consequential onset of throughflow of the ACC. One of the obstacles is putting key regional tectonic events, recorded in southern Patagonian sediments, in absolute time. For that purpose, we have collected Campanian-Eocene sediment samples from the Chilean sector of Southern Patagonia. Using U-Pb radiometric dating on zircons and dinoflagellate cyst biostratigraphy, we updated age constraints for the sedimentary formations, and the hiatuses in between. Thick sedimentary packages of shallowmarine and continental sediments were deposited in the foreland basin during the early Campanian, mid-Paleocene, the Paleocene-Eocene boundary interval and the middle Eocene, which represent phases of increased foreland subsidence. We interpret regional sedimentary hiatuses spanning the late Campanian, early-to mid-Paleocene, mid-Eocene and latest Eocene-early Oligocene to indicate times of reduced foreland subsidence, relative to sediment supply. We relate these changes to varying subduction rates and Andean orogeny. Dinoflagellate cyst assemblages suggest that the region was under the influence of the Antarctic-derived waters through the western boundary current of the Subpolar Gyre, developed in the southwest Atlantic Ocean and thus argues for limited throughflow through the Drake Passage until at least the latest Eocene. However, the proliferation of dinoflagellate endemism we record in the southwest Atlantic is coeval with that in the southwest Pacific, and on a species level, dinoflagellate cyst assemblages are the same in these two regions. This suggests that both regions were oceanographically connected throughout the early Paleogene, likely through a shallow opening of a restricted Drake Passage. This implies a continuous surface-water connection between the south Pacific and the South Atlantic throughout the late Cretaceous-early Paleogene.
- Published
- 2021
38. Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica
- Author
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Hoem, Frida S., primary, Valero, Luis, additional, Evangelinos, Dimitris, additional, Escutia, Carlota, additional, Duncan, Bella, additional, McKay, Robert M., additional, Brinkhuis, Henk, additional, Sangiorgi, Francesca, additional, and Bijl, Peter K., additional
- Published
- 2021
- Full Text
- View/download PDF
39. Campanian-Eocene dinoflagellate cyst biostratigraphy in the Southern Andean foreland basin: Implications for Drake Passage throughflow
- Author
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Bijl, Peter K., primary, Guerstein, G. Raquel, additional, Sanmiguel Jaimes, Edgar A., additional, Sluijs, Appy, additional, Casadio, Silvio, additional, Valencia, Victor, additional, Amenábar, Cecilia R., additional, and Encinas, Alfonso, additional
- Published
- 2021
- Full Text
- View/download PDF
40. Persistent near-tropical warmth on the Antarctic continent during the early Eocene epoch
- Author
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Pross, Jorg, Contreras, Lineth, Bijl, Peter K., Greenwood, David R., Bohaty, Steven M., Schouten, Stefan, Bendle, James A., Rohl, Ursula, Tauxe, Lisa, Raine, J. Ian, Huck, Claire E., van de Flierdt, Tina, Jamieson, Stewart S.R., Stickley, Catherine E., van de Schootbrugge, Bas, Escutia, Carlota, and Brinkhuis, Henk
- Subjects
Atmospheric carbon dioxide -- Environmental aspects ,Climate -- Environmental aspects -- Natural history ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
The warmest global climates of the past 65 million years occurred during the early Eocene epoch (about 55 to 48 million years ago), when the Equator-to-pole temperature gradients were much [...]
- Published
- 2012
41. A warm, stratified, and restricted Labrador Sea across the Middle Eocene and its Climatic Optimum
- Author
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Cramwinckel, Margot J., Coxall, Helen K., Śliwińska, Kasia K., Polling, Marcel, Harper, Dustin T., Bijl, Peter K., Brinkhuis, Henk, Eldrett, James S., Houben, Alexander J.P., Peterse, Francien, Schouten, Stefan, Reichart, Gert Jan, Zachos, James C., Sluijs, Appy, Marine palynology and palaeoceanography, Organic geochemistry, Stratigraphy and paleontology, Marine Palynology, Marine palynology and palaeoceanography, Organic geochemistry, Stratigraphy and paleontology, and Marine Palynology
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Micropaleontology ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Holocene climatic optimum ,Biogeosciences ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,Deep sea ,Foraminifera ,Paleoceanography ,Sea Surface Temperature ,14. Life underwater ,Paleoclimatology ,Research Articles ,0105 earth and related environmental sciences ,biology ,Palaeontology ,North Atlantic Deep Water ,Paleontology ,Macro‐ and Micropaleontology ,TEX86 ,Marine Geology and Geophysics ,Palynology ,biology.organism_classification ,Sea surface temperature ,Thermohaline ,13. Climate action ,Benthic zone ,Atmospheric Processes ,Paleoclimatology and Paleoceanography ,Surface water ,Geology ,Research Article - Abstract
Several studies indicate that North Atlantic Deep Water (NADW) formation might have initiated during the globally warm Eocene (56–34 Ma). However, constraints on Eocene surface ocean conditions in source regions presently conducive to deep water formation are sparse. Here we test whether ocean conditions of the middle Eocene Labrador Sea might have allowed for deep water formation by applying (organic) geochemical and palynological techniques, on sediments from Ocean Drilling Program (ODP) Site 647. We reconstruct a long‐term sea surface temperature (SST) drop from ~30°C to ~27°C between 41.5 to 38.5 Ma, based on TEX86. Superimposed on this trend, we record ~2°C warming in SST associated with the Middle Eocene Climatic Optimum (MECO; ~40 Ma), which is the northernmost MECO record as yet, and another, likely regional, warming phase at ~41.1 Ma, associated with low‐latitude planktic foraminifera and dinoflagellate cyst incursions. Dinoflagellate cyst assemblages together with planktonic foraminiferal stable oxygen isotope ratios overall indicate low surface water salinities and strong stratification. Benthic foraminifer stable carbon and oxygen isotope ratios differ from global deep ocean values by 1–2‰ and 2–4‰, respectively, indicating geographic basin isolation. Our multiproxy reconstructions depict a consistent picture of relatively warm and fresh but also highly variable surface ocean conditions in the middle Eocene Labrador Sea. These conditions were unlikely conducive to deep water formation. This implies either NADW did not yet form during the middle Eocene or it formed in a different source region and subsequently bypassed the southern Labrador Sea., Key Points The middle Eocene Labrador Sea was characterised by warm, low‐salinity surface watersWe find two phases of superimposed sea surface warming and subtropical plankton incursions, including the Middle Eocene Climatic OptimumBottom water stable carbon and oxygen isotope ratios indicate isolated basin
- Published
- 2020
42. Early Palaeogene temperature evolution of the southwest Pacific Ocean
- Author
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Bijl, Peter K., Schouten, Stefan, Sluijs, Appy, Reichart, Gert-Jan, Zachos, James C., and Brinkhuis, Henk
- Subjects
Pacific Ocean -- Thermal properties ,Greenhouse gases -- Research -- Thermal properties -- Environmental aspects ,Atmospheric carbon dioxide -- Research -- Environmental aspects -- Thermal properties ,Ocean -- Thermal properties -- Research -- Environmental aspects ,Climate -- Environmental aspects -- Research -- Thermal properties ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
Relative to the present day, meridional temperature gradients in the Early Eocene age (~56-53Myr ago) were unusually low, with slightly warmer equatorial regions (1) but with much warmer subtropical Arctic (2) and mid-latitude (3) climates. By the end of the Eocene epoch (~34Myr ago), the first major Antarctic ice sheets had appeared (4,5), suggesting that major cooling had taken place. Yet the global transition into this icehouse climate remains poorly constrained, as only a few temperature records are available portraying the Cenozoic climatic evolution of the high southern latitudes. Here we present a uniquely continuous and chronostratigraphically well-calibrated [TEX.sub.86] record of sea surface temperature (SST) from an ocean sediment core in the East Tasman Plateau (palaeolatitude 65° S). We show that southwest Pacific SSTs rose above present-day tropical values (to ~34°C) during the Early Eocene age (~53Myr ago) and had gradually decreased to about 21 °C by the early Late Eocene age (~36Myr ago). Our results imply that there was almost no latitudinal SST gradient between subequatorial and subpolar regions during the Early Eocene age (~55-50Myr ago). Thereafter, the latitudinal gradient markedly increased. In theory, if Eocene cooling was largely driven by a decrease in atmospheric greenhouse gas concentration (6), additional processes are required to explain the relative stability of tropical SSTs given that there was more significant cooling at higher latitudes., The Palaeogene temperature evolution of the Antarctic margin, particularly the Pacific sector, is still poorly resolved. One difficulty with obtaining relevant records close to the Antarctic continent is the general [...]
- Published
- 2009
43. Southern high latitude climate and vegetation changes linked to changes in marine proxies
- Author
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Thompson, A.M., Salzmann, Ulrich, López-Quirós, Adrián, Escutia, Carlota, Bijl, Peter K., and Amoo, M.
- Abstract
UK IODP Annual Meeting 2020. Online, 27-29 August 2020
- Published
- 2020
44. Australian-Antarctic rift-drift transition and development of the Antarctic Circumpolar Current: new IODP drilling in the Australian-Antarctic abyssal plain
- Author
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Bijl, Peter K., Sauermilch, Isabel, McCarthy, Anders, Escutia, Carlota, Whittaker, Joanne, Scher, Howie, Wright, Nicky, Aitken, Alan, Nirrengarten, Michael, Gillard, Morgane, Hochmuth, Katharina, Halpin, Jacqueline, Phipps, Stephen, and Sangiorgi, Francesca
- Published
- 2020
45. The middle to late Eocene greenhouse climate modelled using the CESM 1.0.5
- Author
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Baatsen, Michiel, Von Der Heydt, Anna S., Huber, Matthew, Kliphuis, Michael A., Bijl, Peter K., Sluijs, Appy, Dijkstra, Henk A., Sub Dynamics Meteorology, Sub Physical Oceanography, Marine palynology and palaeoceanography, Marine and Atmospheric Research, Marine Palynology, Sub Dynamics Meteorology, Sub Physical Oceanography, Marine palynology and palaeoceanography, Marine and Atmospheric Research, and Marine Palynology
- Subjects
lcsh:GE1-350 ,Global and Planetary Change ,010504 meteorology & atmospheric sciences ,lcsh:Environmental protection ,Palaeontology ,Stratigraphy ,Paleontology ,15. Life on land ,010502 geochemistry & geophysics ,01 natural sciences ,lcsh:Environmental pollution ,13. Climate action ,lcsh:TD172-193.5 ,lcsh:TD169-171.8 ,lcsh:Environmental sciences ,0105 earth and related environmental sciences - Abstract
The early and late Eocene have both been the subject of many modelling studies, but few have focused on the middle Eocene. The latter still holds many challenges for climate modellers but is also key to understanding the events leading towards the conditions needed for Antarctic glaciation at the Eocene–Oligocene transition. Here, we present the results of CMIP5-like coupled climate simulations using the Community Earth System Model (CESM) version 1. Using a new detailed 38 Ma geography reconstruction and higher model resolution compared to most previous modelling studies and sufficiently long equilibration times, these simulations will help to further understand the middle to late Eocene climate. At realistic levels of atmospheric greenhouse gases, the model is able to show overall good agreement with proxy records and capture the important aspects of a warm greenhouse climate during the Eocene. With a quadrupling of pre-industrial concentrations of both CO2 and CH4 (i.e. 1120 ppm and ∼2700 ppb, respectively, or 4 × PIC; pre-industrial carbon), sea surface temperatures correspond well to the available late middle Eocene (42–38 Ma; ∼ Bartonian) proxies. Being generally cooler, the simulated climate under 2 × PIC forcing is a good analogue for that of the late Eocene (38–34 Ma; ∼ Priabonian). Terrestrial temperature proxies, although their geographical coverage is sparse, also indicate that the results presented here are in agreement with the available information. Our simulated middle to late Eocene climate has a reduced Equator-to-pole temperature gradient and a more symmetric meridional heat distribution compared to the pre-industrial reference. The collective effects of geography, vegetation, and ice account for a global average 5–7 ∘C difference between pre-industrial and 38 Ma Eocene boundary conditions, with important contributions from cloud and water vapour feedbacks. This helps to explain Eocene warmth in general, without the need for greenhouse gas levels much higher than indicated by proxy estimates (i.e. ∼500–1200 ppm CO2) or low-latitude regions becoming unreasonably warm. High-latitude warmth supports the idea of mostly ice-free polar regions, even at 2 × PIC, with Antarctica experiencing particularly warm summers. An overall wet climate is seen in the simulated Eocene climate, which has a strongly monsoonal character. Equilibrium climate sensitivity is reduced (0.62 ∘C W−1 m2; 3.21 ∘C warming between 38 Ma 2 × PIC and 4 × PIC) compared to that of the present-day climate (0.80 ∘C W−1 m2; 3.17 ∘C per CO2 doubling). While the actual warming is similar, we see mainly a higher radiative forcing from the second PIC doubling. A more detailed analysis of energy fluxes shows that the regional radiative balance is mainly responsible for sustaining a low meridional temperature gradient in the Eocene climate, as well as the polar amplification seen towards even warmer conditions. These model results may be useful to reconsider the drivers of Eocene warmth and the Eocene–Oligocene transition (EOT) but can also be a base for more detailed comparisons to future proxy estimates.
- Published
- 2020
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46. Resolution dependency of sinking Lagrangian particles in ocean general circulation models
- Author
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Nooteboom, Peter D., primary, Delandmeter, Philippe, additional, van Sebille, Erik, additional, Bijl, Peter K., additional, Dijkstra, Henk A., additional, and von der Heydt, Anna S., additional
- Published
- 2020
- Full Text
- View/download PDF
47. Subduction initiation in the Scotia Sea region and opening of the Drake Passage: When and why?
- Author
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van de Lagemaat, Suzanna H.A., Swart, Merel L.A., Vaes, Bram, Kosters, Martha E., Boschman, Lydian M., Burton-Johnson, Alex, Bijl, Peter K., Spakman, Wim, van Hinsbergen, Douwe J.J., Mantle dynamics & theoretical geophysics, Paleomagnetism, Marine palynology and palaeoceanography, Marine Palynology, Mantle dynamics & theoretical geophysics, Paleomagnetism, Marine palynology and palaeoceanography, and Marine Palynology
- Subjects
Lithosphere delamination ,010504 meteorology & atmospheric sciences ,Subduction ,Continental crust ,Earth and Planetary Sciences(all) ,South Sandwich subduction initiation ,010502 geochemistry & geophysics ,01 natural sciences ,Scotia Sea ,Mantle (geology) ,Drake Passage ,Kinematic reconstruction ,GPLates ,Tectonics ,Paleontology ,GPlates ,13. Climate action ,Lithosphere ,Oceanic crust ,Trench ,South American Plate ,General Earth and Planetary Sciences ,14. Life underwater ,Geology ,0105 earth and related environmental sciences - Abstract
During evolution of the South Sandwich subduction zone, which has consumed South American plate oceanic lithosphere, somehow continental crust of both the South American and Antarctic plates have become incorporated into its upper plate. Continental fragments of both plates are currently separated by small oceanic basins in the upper plate above the South Sandwich subduction zone, in the Scotia Sea region, but how fragments of both continents became incorporated in the same upper plate remains enigmatic. Here we present an updated kinematic reconstruction of the Scotia Sea region using the latest published marine magnetic anomaly constraints, and place this in a South America-Africa-Antarctica plate circuit in which we take intracontinental deformation into account. We show that a change in fracture zone orientation in the Weddell Sea requires that previously inferred initiation of subduction of South American oceanic crust of the northern Weddell below the eastern margin of South Orkney Islands continental crust, then still attached to the Antarctic Peninsula, already occurred around 80 Ma. We propose that subsequently, between ~71-50 Ma, the trench propagated northwards into South America by delamination of South American lithosphere: this resulted in the transfer of delaminated South American continental crust to the overriding plate of the South Sandwich subduction zone. We show continental delamination may have been facilitated by absolute southward motion of South America that was resisted by South Sandwich slab dragging. Pre-drift extension preceding the oceanic Scotia Sea basins led around 50 Ma to opening of the Drake Passage, preconditioning the southern ocean for the Antarctic Circumpolar Current. This 50 Ma extension was concurrent with a strong change in absolute plate motion of the South American Plate that changed from S to WNW, leading to upper plate retreat relative to the more or less mantle stationary South Sandwich Trench that did not partake in the absolute plate motion change. While subduction continued, this mantle-stationary trench setting lasted until ~30 Ma, after which rollback started to contribute to back-arc extension. We find that roll-back and upper plate retreat have contributed more or less equally to the total amount of ~2000 km of extension accommodated in the Scotia Sea basins. We highlight that viewing tectonic motions in a context of absolute plate motion is key for identifying slab motion (e.g. rollback, trench-parallel slab dragging) and consequently mantle-forcing of geological processes.
- Published
- 2021
48. Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and 푝CO2.
- Author
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Amoo, Michael, Salzmann, Ulrich, Pound, Matthew J., Thompson, Nick, and Bijl, Peter K.
- Abstract
Considered as one of the most significant climate reorganisations of the Cenozoic period, the Eocene-Oligocene Transition (EOT; ca. 34.44-33.65) is characterised by global cooling and the first major glacial advance on Antarctica. While in the southern high-latitudes, the EOT cooling is primarily recorded in the marine realm, the extent and effect on terrestrial climate and vegetation is poorly documented. Here, we present a new, well-dated, continuous, high-resolution palynological (sporomorph) data and quantitative sporomorph-based climate estimates recovered from the East Tasman Plateau (ODP Site 1172) to reconstruct climate and vegetation dynamics from the late Eocene (37.97 Ma) to early Oligocene (33.06 Ma). Our results indicate three major climate transitions and four vegetation communities occupying Tasmania under different precipitation and temperature regimes: (i) a warm-temperate Nothofagus-Podocarpaceae dominated rainforest with paratropical elements from 37.97-37.52 Ma; (ii) cool-temperate Nothofagus dominated rainforest with secondary Podocarpaceae rapidly expanding and taking over regions previously occupied by the warmer taxa between 37.306-35.60 Ma; (iii) fluctuation between warm temperate - paratropical taxa and cool temperate forest from 35.50-34.49 Ma, followed by a cool phase across the EOT (34.30-33.82 Ma); (iv) post-EOT (earliest Oligocene) recovery characterised by a warm-temperate forest association from 33.55-33.06 Ma. Coincident with changes in stratification of water masses and sequestration of carbon from surface water in the Southern Ocean, our sporomorph-based temperature estimates between 37.52 Ma and 35.60 Ma (phase ii) showed 2-3 ºC terrestrial cooling. The unusual fluctuation between warm and cold temperate forest between 35.50 to 34.59 Ma is suggested to be linked to the initial deepening of the Tasmanian Gateway allowing eastern Tasmania to come under the influence of warm water associated with the proto-Leeuwin Current (PLC). Further to the above, our terrestrial data show mean annual temperature declining by about 2 ºC across the EOT before recovering in the earliest Oligocene. This phenomenon is synchronous with regional and global cooling during the EOT and linked to declining 푝CO
2 . However, the earliest Oligocene climate rebound along eastern Tasmania is linked to transient recovery of atmospheric 푝CO2 and sustained deepening of the Tasmanian Gateway, promoting PLC throughflow. The three main climate transitional events across the studied interval (late Eocene-earliest Oligocene) in the Tasmanian Gateway region suggest that changes in ocean circulation due to accelerated deepening of the Tasmanian Gateway may not have been solely responsible for the changes in terrestrial climate and vegetation dynamics, but a series of regional and global events, including a change in stratification of water masses, sequestration of carbon from surface waters, and changes in 푝CO2 may have played vital roles. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
49. Proposed IODP drilling in the Southern Ocean: Australian-Antarctic rift-drift transition and development of the Antarctic Circumpolar Current
- Author
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Bijl, Peter K., Sauermilch, Isabel, McCarthy, Anders, Escutia, Carlota, Whittaker, Joanne, Scher, Howard, Wright, Nicky, Aitken, Alan, Gillard, Morgane, Nirrengarten, Michael, Hochmuth, Katharina, Halpin, Jacqueline, Phipps, Stephen, and Sangiorgi, Francesca
- Abstract
13th International Conference on Paleoceanography, 2-6 September 2019 Sydney, Australia
- Published
- 2019
50. Early Oligocene to middle Miocene surface ocean conditions offshore Cape Adare (Ross Sea, Antarctica); palynological and temperature records of DSDP Site 274
- Author
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Hoem, Frida S., Evangelinos, Dimitris, Escutia, Carlota, Sangiorgi, Francesca, Brinkhuis, Henk, and Bijl, Peter K.
- Abstract
13th International Conference on Paleoceanography 2-6 September 2019 Sydney, Australia
- Published
- 2019
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