Articles | Volume 15, issue 3
https://doi.org/10.5194/cp-15-943-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-15-943-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 May 2019
Research article |
| 27 May 2019
| 27 May 2019
Understanding the mechanisms behind high glacial productivity in the southern Brazilian margin
Rodrigo da Costa Portilho-Ramos
CORRESPONDING AUTHOR
MARUM – Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse, 28359 Bremen, Germany
Institute of Geosciences, University of São Paulo, Rua do Lago 562, CEP05508-080, São Paulo, Brazil
Tainã Marcos Lima Pinho
Institute of Geosciences, University of São Paulo, Rua do Lago 562, CEP05508-080, São Paulo, Brazil
School of Arts, Sciences and Humanities, University of São Paulo, Rua Arlindo Bettio 1000, CEP03828-000, São Paulo, Brazil
Cristiano Mazur Chiessi
School of Arts, Sciences and Humanities, University of São Paulo, Rua Arlindo Bettio 1000, CEP03828-000, São Paulo, Brazil
Cátia Fernandes Barbosa
Departamento de Geoquímica, Universidade Federal Fluminense, Rua Outeiro São João Baptista S/N, CEP24020-141, Niterói, Brazil
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Nico Wunderling, Anna von der Heydt, Yevgeny Aksenov, Stephen Barker, Robbin Bastiaansen, Victor Brovkin, Maura Brunetti, Victor Couplet, Thomas Kleinen, Caroline H. Lear, Johannes Lohmann, Rosa Maria Roman-Cuesta, Sacha Sinet, Didier Swingedouw, Ricarda Winkelmann, Pallavi Anand, Jonathan Barichivich, Sebastian Bathiany, Mara Baudena, John T. Bruun, Christiano M. Chiessi, Helen K. Coxall, David Docquier, Jonathan F. Donges, Swinda K. J. Falkena, Ann Kristin Klose, David Obura, Juan Rocha, Stefanie Rynders, Norman Julius Steinert, and Matteo Willeit
EGUsphere, https://doi.org/10.5194/egusphere-2023-1576, https://doi.org/10.5194/egusphere-2023-1576, 2023
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This paper reviews the state-of-the-art literature on interactions between tipping elements and discusses the risk of potential tipping cascades under ongoing global warming. Specifically, we review the current knowledge on interactions between pairs of tipping elements from models to observations, review archetypal examples of tipping cascades in the past, and outline how future developments could improve our understanding of climate tipping element interactions.
Daniel François, Adina Paytan, Olga Maria Oliveira de Araújo, Ricardo Tadeu Lopes, and Cátia Fernandes Barbosa
Biogeosciences, 19, 5269–5285, https://doi.org/10.5194/bg-19-5269-2022, https://doi.org/10.5194/bg-19-5269-2022, 2022
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Our analysis revealed that under the two most conservative acidification projections foraminifera assemblages did not display considerable changes. However, a significant decrease in species richness was observed when pH decreases to 7.7 pH units, indicating adverse effects under high-acidification scenarios. A micro-CT analysis revealed that calcified tests of Archaias angulatus were of lower density in low pH, suggesting no acclimation capacity for this species.
Stefan Mulitza, Torsten Bickert, Helen C. Bostock, Cristiano M. Chiessi, Barbara Donner, Aline Govin, Naomi Harada, Enqing Huang, Heather Johnstone, Henning Kuhnert, Michael Langner, Frank Lamy, Lester Lembke-Jene, Lorraine Lisiecki, Jean Lynch-Stieglitz, Lars Max, Mahyar Mohtadi, Gesine Mollenhauer, Juan Muglia, Dirk Nürnberg, André Paul, Carsten Rühlemann, Janne Repschläger, Rajeev Saraswat, Andreas Schmittner, Elisabeth L. Sikes, Robert F. Spielhagen, and Ralf Tiedemann
Earth Syst. Sci. Data, 14, 2553–2611, https://doi.org/10.5194/essd-14-2553-2022, https://doi.org/10.5194/essd-14-2553-2022, 2022
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Stable isotope ratios of foraminiferal shells from deep-sea sediments preserve key information on the variability of ocean circulation and ice volume. We present the first global atlas of harmonized raw downcore oxygen and carbon isotope ratios of various planktonic and benthic foraminiferal species. The atlas is a foundation for the analyses of the history of Earth system components, for finding future coring sites, and for teaching marine stratigraphy and paleoceanography.
Anna Paula Soares Cruz, Cátia Fernandes Barbosa, Angélica Maria Blanco, Camila Areias de Oliveira, Cleverson Guizan Silva, and José Carlos Sícoli Seoane
Clim. Past, 15, 1363–1373, https://doi.org/10.5194/cp-15-1363-2019, https://doi.org/10.5194/cp-15-1363-2019, 2019
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Salgada Lagoon is a hypersaline lake investigated for its sedimentation history in order to interpret past climatic events. We studied the geochemistry of sediments from 5800 years ago until the present and found sea level oscillations, different climatic conditions, and proxies for vegetation cover and productivity, which highlight a dry event 4200 years ago that matches a global event of the same age, marking changes to favorable conditions for carbonates microbial mats and stromatolites.
Shuwen Sun, Enno Schefuß, Stefan Mulitza, Cristiano M. Chiessi, André O. Sawakuchi, Matthias Zabel, Paul A. Baker, Jens Hefter, and Gesine Mollenhauer
Biogeosciences, 14, 2495–2512, https://doi.org/10.5194/bg-14-2495-2017, https://doi.org/10.5194/bg-14-2495-2017, 2017
Marília C. Campos, Cristiano M. Chiessi, Ines Voigt, Alberto R. Piola, Henning Kuhnert, and Stefan Mulitza
Clim. Past, 13, 345–358, https://doi.org/10.5194/cp-13-345-2017, https://doi.org/10.5194/cp-13-345-2017, 2017
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Our new planktonic foraminiferal stable carbon isotopic data from the western South Atlantic show major decreases during abrupt climate change events of the last glacial. These anomalies are likely related to periods of a sluggish Atlantic meridional overturning circulation and increase (decrease) in atmospheric CO2 (stable carbon isotopic ratios). We hypothesize that strengthening of Southern Ocean deep-water ventilation and weakening of the biological pump are responsible for these decreases.
P. A. Baker, S. C. Fritz, C. G. Silva, C. A. Rigsby, M. L. Absy, R. P. Almeida, M. Caputo, C. M. Chiessi, F. W. Cruz, C. W. Dick, S. J. Feakins, J. Figueiredo, K. H. Freeman, C. Hoorn, C. Jaramillo, A. K. Kern, E. M. Latrubesse, M. P. Ledru, A. Marzoli, A. Myrbo, A. Noren, W. E. Piller, M. I. F. Ramos, C. C. Ribas, R. Trnadade, A. J. West, I. Wahnfried, and D. A. Willard
Sci. Dril., 20, 41–49, https://doi.org/10.5194/sd-20-41-2015, https://doi.org/10.5194/sd-20-41-2015, 2015
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We report on a planned Trans-Amazon Drilling Project (TADP) that will continuously sample Late Cretaceous to modern sediment in a transect along the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The TADP will document the evolution of the Neotropical forest and will link biotic diversification to changes in the physical environment, including climate, tectonism, and landscape. We will also sample the ca. 200Ma basaltic sills that underlie much of the Amazon.
C. Häggi, C. M. Chiessi, and E. Schefuß
Biogeosciences, 12, 7239–7249, https://doi.org/10.5194/bg-12-7239-2015, https://doi.org/10.5194/bg-12-7239-2015, 2015
C. M. Chiessi, S. Mulitza, G. Mollenhauer, J. B. Silva, J. Groeneveld, and M. Prange
Clim. Past, 11, 915–929, https://doi.org/10.5194/cp-11-915-2015, https://doi.org/10.5194/cp-11-915-2015, 2015
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Here we show that temperatures in the western South Atlantic increased markedly during the major slowdown event of the Atlantic meridional overturning circulation (AMOC) of the last deglaciation. Over the adjacent continent, however, temperatures followed the rise in atmospheric carbon dioxide, lagging changes in oceanic temperature. Our records corroborate the notion that the long duration of the major slowdown event of the AMOC was fundamental in driving the Earth out of the last glacial.
A. Govin, C. M. Chiessi, M. Zabel, A. O. Sawakuchi, D. Heslop, T. Hörner, Y. Zhang, and S. Mulitza
Clim. Past, 10, 843–862, https://doi.org/10.5194/cp-10-843-2014, https://doi.org/10.5194/cp-10-843-2014, 2014
L. F. Prado, I. Wainer, C. M. Chiessi, M.-P. Ledru, and B. Turcq
Clim. Past, 9, 2117–2133, https://doi.org/10.5194/cp-9-2117-2013, https://doi.org/10.5194/cp-9-2117-2013, 2013
Related subject area
Subject: Ocean Dynamics | Archive: Marine Archives | Timescale: Cenozoic
Limited exchange between the deep Pacific and Atlantic oceans during the warm mid-Pliocene and Marine Isotope Stage M2 “glaciation”
Late Cenozoic sea-surface-temperature evolution of the South Atlantic Ocean
Buoyancy forcing: a key driver of northern North Atlantic sea surface temperature variability across multiple timescales
Nonlinear increase in seawater 87Sr/86Sr in the Oligocene to early Miocene and implications for climate-sensitive weathering
Lipid-biomarker-based sea surface temperature record offshore Tasmania over the last 23 million years
Late Neogene nannofossil assemblages as tracers of ocean circulation and paleoproductivity over the NW Australian shelf
Plio-Pleistocene Perth Basin water temperatures and Leeuwin Current dynamics (Indian Ocean) derived from oxygen and clumped-isotope paleothermometry
Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica
A revised mid-Pliocene composite section centered on the M2 glacial event for ODP Site 846
Lessons from a high-CO2 world: an ocean view from ∼ 3 million years ago
Late Pliocene Cordilleran Ice Sheet development with warm northeast Pacific sea surface temperatures
Paleoceanography and ice sheet variability offshore Wilkes Land, Antarctica – Part 3: Insights from Oligocene–Miocene TEX86-based sea surface temperature reconstructions
Paleoceanography and ice sheet variability offshore Wilkes Land, Antarctica – Part 2: Insights from Oligocene–Miocene dinoflagellate cyst assemblages
Variations in Mediterranean–Atlantic exchange across the late Pliocene climate transition
Revisiting the Ceara Rise, equatorial Atlantic Ocean: isotope stratigraphy of ODP Leg 154 from 0 to 5 Ma
Constraints on ocean circulation at the Paleocene–Eocene Thermal Maximum from neodymium isotopes
Expansion and diversification of high-latitude radiolarian assemblages in the late Eocene linked to a cooling event in the southwest Pacific
Microfossil evidence for trophic changes during the Eocene–Oligocene transition in the South Atlantic (ODP Site 1263, Walvis Ridge)
A major change in North Atlantic deep water circulation 1.6 million years ago
Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling
Productivity response of calcareous nannoplankton to Eocene Thermal Maximum 2 (ETM2)
Technical note: Late Pliocene age control and composite depths at ODP Site 982, revisited
Pliocene three-dimensional global ocean temperature reconstruction
Anna Hauge Braaten, Kim A. Jakob, Sze Ling Ho, Oliver Friedrich, Eirik Vinje Galaasen, Stijn De Schepper, Paul A. Wilson, and Anna Nele Meckler
Clim. Past, 19, 2109–2125, https://doi.org/10.5194/cp-19-2109-2023, https://doi.org/10.5194/cp-19-2109-2023, 2023
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In the context of understanding current global warming, the middle Pliocene (3.3–3.0 million years ago) is an important interval in Earth's history because atmospheric carbon dioxide concentrations were similar to levels today. We have reconstructed deep-sea temperatures at two different locations for this period, and find that a very different mode of ocean circulation or mixing existed, with important implications for how heat was transported in the deep ocean.
Frida S. Hoem, Adrián López-Quirós, Suzanna van de Lagemaat, Johan Etourneau, Marie-Alexandrine Sicre, Carlota Escutia, Henk Brinkhuis, Francien Peterse, Francesca Sangiorgi, and Peter K. Bijl
Clim. Past, 19, 1931–1949, https://doi.org/10.5194/cp-19-1931-2023, https://doi.org/10.5194/cp-19-1931-2023, 2023
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We present two new sea surface temperature (SST) records in comparison with available SST records to reconstruct South Atlantic paleoceanographic evolution. Our results show a low SST gradient in the Eocene–early Oligocene due to the persistent gyral circulation. A higher SST gradient in the Middle–Late Miocene infers a stronger circumpolar current. The southern South Atlantic was the coldest region in the Southern Ocean and likely the main deep-water formation location in the Middle Miocene.
Bjørg Risebrobakken, Mari F. Jensen, Helene R. Langehaug, Tor Eldevik, Anne Britt Sandø, Camille Li, Andreas Born, Erin Louise McClymont, Ulrich Salzmann, and Stijn De Schepper
Clim. Past, 19, 1101–1123, https://doi.org/10.5194/cp-19-1101-2023, https://doi.org/10.5194/cp-19-1101-2023, 2023
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In the observational period, spatially coherent sea surface temperatures characterize the northern North Atlantic at multidecadal timescales. We show that spatially non-coherent temperature patterns are seen both in further projections and a past warm climate period with a CO2 level comparable to the future low-emission scenario. Buoyancy forcing is shown to be important for northern North Atlantic temperature patterns.
Heather M. Stoll, Leopoldo D. Pena, Ivan Hernandez-Almeida, José Guitián, Thomas Tanner, and Heiko Paelike
Clim. Past Discuss., https://doi.org/10.5194/cp-2023-29, https://doi.org/10.5194/cp-2023-29, 2023
Revised manuscript accepted for CP
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The Oligocene and Early Miocene periods featured dynamic glacial cycles on Antarctica. In this paper, we use Sr isotopes in marine carbonate sediments to document a change in the location and intensity of continental weathering during short periods of very intense Antartic glaciation. Potentially, the weathering intensity of old continental rocks on Antarctica was reduced during glaciation. We also show improved age models for correlation of Southern ocean and North Atlantic sediments.
Suning Hou, Foteini Lamprou, Frida S. Hoem, Mohammad Rizky Nanda Hadju, Francesca Sangiorgi, Francien Peterse, and Peter K. Bijl
Clim. Past, 19, 787–802, https://doi.org/10.5194/cp-19-787-2023, https://doi.org/10.5194/cp-19-787-2023, 2023
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Neogene climate cooling is thought to be accompanied by increased Equator-to-pole temperature gradients, but mid-latitudes are poorly represented. We use biomarkers to reconstruct a 23 Myr continuous sea surface temperature record of the mid-latitude Southern Ocean. We note a profound mid-latitude cooling which narrowed the latitudinal temperature gradient with the northward expansion of subpolar conditions. We surmise that this reflects the strengthening of the ACC and the expansion of sea ice.
Boris-Theofanis Karatsolis and Jorijntje Henderiks
Clim. Past, 19, 765–786, https://doi.org/10.5194/cp-19-765-2023, https://doi.org/10.5194/cp-19-765-2023, 2023
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Ocean circulation around NW Australia plays a key role in regulating the climate in the area and is characterised by seasonal variations in the activity of a major boundary current named the Leeuwin Current. By investigating nannofossils found in sediment cores recovered from the NW Australian shelf, we reconstructed ocean circulation in the warmer-than-present world from 6 to 3.5 Ma, as mirrored by long-term changes in stratification and nutrient availability.
David De Vleeschouwer, Marion Peral, Marta Marchegiano, Angelina Füllberg, Niklas Meinicke, Heiko Pälike, Gerald Auer, Benjamin Petrick, Christophe Snoeck, Steven Goderis, and Philippe Claeys
Clim. Past, 18, 1231–1253, https://doi.org/10.5194/cp-18-1231-2022, https://doi.org/10.5194/cp-18-1231-2022, 2022
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The Leeuwin Current transports warm water along the western coast of Australia: from the tropics to the Southern Hemisphere midlatitudes. Therewith, the current influences climate in two ways: first, as a moisture source for precipitation in southwestern Australia; second, as a vehicle for Equator-to-pole heat transport. In this study, we study sediment cores along the Leeuwin Current pathway to understand its ocean–climate interactions between 4 and 2 Ma.
Frida S. Hoem, Luis Valero, Dimitris Evangelinos, Carlota Escutia, Bella Duncan, Robert M. McKay, Henk Brinkhuis, Francesca Sangiorgi, and Peter K. Bijl
Clim. Past, 17, 1423–1442, https://doi.org/10.5194/cp-17-1423-2021, https://doi.org/10.5194/cp-17-1423-2021, 2021
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We present new offshore palaeoceanographic reconstructions for the Oligocene (33.7–24.4 Ma) in the Ross Sea, Antarctica. Our study of dinoflagellate cysts and lipid biomarkers indicates warm-temperate sea surface conditions. We posit that warm surface-ocean conditions near the continental shelf during the Oligocene promoted increased precipitation and heat delivery towards Antarctica that led to dynamic terrestrial ice sheet volumes in the warmer climate state of the Oligocene.
Timothy D. Herbert, Rocio Caballero-Gill, and Joseph B. Novak
Clim. Past, 17, 1385–1394, https://doi.org/10.5194/cp-17-1385-2021, https://doi.org/10.5194/cp-17-1385-2021, 2021
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The Pliocene represents a geologically warm period with polar ice restricted to the Antarctic. Nevertheless, variability and ice volume persisted in the Pliocene. This work revisits a classic site on which much of our understanding of Pliocene paleoclimate variability is based and corrects errors in data sets related to ice volume and ocean surface temperature. In particular, it generates an improved representation of an enigmatic glacial episode in Pliocene times (circa 3.3 Ma).
Erin L. McClymont, Heather L. Ford, Sze Ling Ho, Julia C. Tindall, Alan M. Haywood, Montserrat Alonso-Garcia, Ian Bailey, Melissa A. Berke, Kate Littler, Molly O. Patterson, Benjamin Petrick, Francien Peterse, A. Christina Ravelo, Bjørg Risebrobakken, Stijn De Schepper, George E. A. Swann, Kaustubh Thirumalai, Jessica E. Tierney, Carolien van der Weijst, Sarah White, Ayako Abe-Ouchi, Michiel L. J. Baatsen, Esther C. Brady, Wing-Le Chan, Deepak Chandan, Ran Feng, Chuncheng Guo, Anna S. von der Heydt, Stephen Hunter, Xiangyi Li, Gerrit Lohmann, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, W. Richard Peltier, Christian Stepanek, and Zhongshi Zhang
Clim. Past, 16, 1599–1615, https://doi.org/10.5194/cp-16-1599-2020, https://doi.org/10.5194/cp-16-1599-2020, 2020
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We examine the sea-surface temperature response to an interval of climate ~ 3.2 million years ago, when CO2 concentrations were similar to today and the near future. Our geological data and climate models show that global mean sea-surface temperatures were 2.3 to 3.2 ºC warmer than pre-industrial climate, that the mid-latitudes and high latitudes warmed more than the tropics, and that the warming was particularly enhanced in the North Atlantic Ocean.
Maria Luisa Sánchez-Montes, Erin L. McClymont, Jeremy M. Lloyd, Juliane Müller, Ellen A. Cowan, and Coralie Zorzi
Clim. Past, 16, 299–313, https://doi.org/10.5194/cp-16-299-2020, https://doi.org/10.5194/cp-16-299-2020, 2020
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In this paper, we present new climate reconstructions in SW Alaska from recovered marine sediments in the Gulf of Alaska. We find that glaciers reached the Gulf of Alaska during a cooling climate 2.9 million years ago, and after that the Cordilleran Ice Sheet continued growing during a global drop in atmospheric CO2 levels. Cordilleran Ice Sheet growth could have been supported by an increase in heat supply to the SW Alaska and warm ocean evaporation–mountain precipitation mechanisms.
Julian D. Hartman, Francesca Sangiorgi, Ariadna Salabarnada, Francien Peterse, Alexander J. P. Houben, Stefan Schouten, Henk Brinkhuis, Carlota Escutia, and Peter K. Bijl
Clim. Past, 14, 1275–1297, https://doi.org/10.5194/cp-14-1275-2018, https://doi.org/10.5194/cp-14-1275-2018, 2018
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We reconstructed sea surface temperatures for the Oligocene and Miocene periods (34–11 Ma) based on archaeal lipids from a site close to the Wilkes Land coast, Antarctica. Our record suggests generally warm to temperate surface waters: on average 17 °C. Based on the lithology, glacial and interglacial temperatures could be distinguished, showing an average 3 °C offset. The long-term temperature trend resembles the benthic δ18O stack, which may have implications for ice volume reconstructions.
Peter K. Bijl, Alexander J. P. Houben, Julian D. Hartman, Jörg Pross, Ariadna Salabarnada, Carlota Escutia, and Francesca Sangiorgi
Clim. Past, 14, 1015–1033, https://doi.org/10.5194/cp-14-1015-2018, https://doi.org/10.5194/cp-14-1015-2018, 2018
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We document Southern Ocean surface ocean conditions and changes therein during the Oligocene and Miocene (34–10 Myr ago). We infer profound long-term and short-term changes in ice-proximal oceanographic conditions: sea surface temperature, nutrient conditions and sea ice. Our results point to warm-temperate, oligotrophic, ice-proximal oceanographic conditions. These distinct oceanographic conditions may explain the high amplitude in inferred Oligocene–Miocene Antarctic ice volume changes.
Ángela García-Gallardo, Patrick Grunert, and Werner E. Piller
Clim. Past, 14, 339–350, https://doi.org/10.5194/cp-14-339-2018, https://doi.org/10.5194/cp-14-339-2018, 2018
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We study the variability in Mediterranean–Atlantic exchange, focusing on the surface Atlantic inflow across the mid-Pliocene warm period and the onset of the Northern Hemisphere glaciation, still unresolved by previous works. Oxygen isotope gradients between both sides of the Strait of Gibraltar reveal weak inflow during warm periods that turns stronger during severe glacials and the start of a negative feedback between exchange at the Strait and the Atlantic Meridional Overturning Circulation.
Roy H. Wilkens, Thomas Westerhold, Anna J. Drury, Mitchell Lyle, Thomas Gorgas, and Jun Tian
Clim. Past, 13, 779–793, https://doi.org/10.5194/cp-13-779-2017, https://doi.org/10.5194/cp-13-779-2017, 2017
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Here we introduce the Code for Ocean Drilling Data (CODD), a unified and consistent system for integrating disparate data streams such as micropaleontology, physical properties, core images, geochemistry, and borehole logging. As a test case, data from Ocean Drilling Program Leg 154 (Ceara Rise – western equatorial Atlantic) were assembled into a new regional composite benthic stable isotope record covering the last 5 million years.
April N. Abbott, Brian A. Haley, Aradhna K. Tripati, and Martin Frank
Clim. Past, 12, 837–847, https://doi.org/10.5194/cp-12-837-2016, https://doi.org/10.5194/cp-12-837-2016, 2016
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The Paleocene-Eocene Thermal Maximum (PETM) was a brief period when the Earth was in an extreme greenhouse state. We use neodymium isotopes to suggest that during this time deep-ocean circulation was distinct in each basin (North and South Atlanic, Southern, Pacific) with little exchange between. Moreover, the Pacific data show the most variability, suggesting this was a critical region possibly involved in both PETM triggering and remediation.
K. M. Pascher, C. J. Hollis, S. M. Bohaty, G. Cortese, R. M. McKay, H. Seebeck, N. Suzuki, and K. Chiba
Clim. Past, 11, 1599–1620, https://doi.org/10.5194/cp-11-1599-2015, https://doi.org/10.5194/cp-11-1599-2015, 2015
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Radiolarian taxa with high-latitude affinities are present from at least the middle Eocene in the SW Pacific and become very abundant in the late Eocene at all investigated sites. A short incursion of low-latitude taxa is observed during the MECO and late Eocene warming event at Site 277. Radiolarian abundance, diversity and taxa with high-latitude affinities increase at Site 277 in two steps in the latest Eocene due to climatic cooling and expansion of cold water masses.
M. Bordiga, J. Henderiks, F. Tori, S. Monechi, R. Fenero, A. Legarda-Lisarri, and E. Thomas
Clim. Past, 11, 1249–1270, https://doi.org/10.5194/cp-11-1249-2015, https://doi.org/10.5194/cp-11-1249-2015, 2015
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Deep-sea sediments at ODP Site 1263 (Walvis Ridge, South Atlantic) show that marine calcifying algae decreased in abundance and size at the Eocene-Oligocene boundary, when the Earth transitioned from a greenhouse to a more glaciated and cooler climate. This decreased the food supply for benthic foraminifer communities. The plankton rapidly responded to fast-changing conditions, such as seasonal nutrient availability, or to threshold-levels in pCO2, cooling and ocean circulation.
N. Khélifi and M. Frank
Clim. Past, 10, 1441–1451, https://doi.org/10.5194/cp-10-1441-2014, https://doi.org/10.5194/cp-10-1441-2014, 2014
J. Etourneau, C. Ehlert, M. Frank, P. Martinez, and R. Schneider
Clim. Past, 8, 1435–1445, https://doi.org/10.5194/cp-8-1435-2012, https://doi.org/10.5194/cp-8-1435-2012, 2012
M. Dedert, H. M. Stoll, D. Kroon, N. Shimizu, K. Kanamaru, and P. Ziveri
Clim. Past, 8, 977–993, https://doi.org/10.5194/cp-8-977-2012, https://doi.org/10.5194/cp-8-977-2012, 2012
N. Khélifi, M. Sarnthein, and B. D. A. Naafs
Clim. Past, 8, 79–87, https://doi.org/10.5194/cp-8-79-2012, https://doi.org/10.5194/cp-8-79-2012, 2012
H. J. Dowsett, M. M. Robinson, and K. M. Foley
Clim. Past, 5, 769–783, https://doi.org/10.5194/cp-5-769-2009, https://doi.org/10.5194/cp-5-769-2009, 2009
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Short summary
Fossil microorganisms from the last glacial found in marine sediments collected off southern Brazil suggest that more productive austral summer upwelling and more frequent austral winter incursions of nutrient-rich waters from the Plata River boosted regional productivity year-round. While upwelling was more productive due to the higher silicon content from the Southern Ocean, more frequent riverine incursions were modulated by stronger alongshore southwesterly winds.
Fossil microorganisms from the last glacial found in marine sediments collected off southern...
