Articles | Volume 14, issue 7
https://doi.org/10.5194/cp-14-1079-2018
© Author(s) 2018. 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-14-1079-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
25 Jul 2018
Research article |
| 25 Jul 2018
| 25 Jul 2018
Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation
Kim Alix Jakob
CORRESPONDING AUTHOR
Institute of Earth Sciences, Heidelberg University, 69120 Heidelberg,
Germany
Jörg Pross
Institute of Earth Sciences, Heidelberg University, 69120 Heidelberg,
Germany
Christian Scholz
Institute of Earth Sciences, Heidelberg University, 69120 Heidelberg,
Germany
Jens Fiebig
Institute of Geosciences, Goethe University Frankfurt, 60438
Frankfurt, Germany
Oliver Friedrich
Institute of Earth Sciences, Heidelberg University, 69120 Heidelberg,
Germany
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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.
Emilija Krsnik, Katharina Methner, Marion Campani, Svetlana Botsyun, Sebastian G. Mutz, Todd A. Ehlers, Oliver Kempf, Jens Fiebig, Fritz Schlunegger, and Andreas Mulch
Solid Earth, 12, 2615–2631, https://doi.org/10.5194/se-12-2615-2021, https://doi.org/10.5194/se-12-2615-2021, 2021
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Here we present new surface elevation constraints for the middle Miocene Central Alps based on stable and clumped isotope geochemical analyses. Our reconstructed paleoelevation estimate is supported by isotope-enabled paleoclimate simulations and indicates that the Miocene Central Alps were characterized by a heterogeneous and spatially transient topography with high elevations locally exceeding 4000 m.
Nicolai Schleinkofer, David Evans, Max Wisshak, Janina Vanessa Büscher, Jens Fiebig, André Freiwald, Sven Härter, Horst R. Marschall, Silke Voigt, and Jacek Raddatz
Biogeosciences, 18, 4733–4753, https://doi.org/10.5194/bg-18-4733-2021, https://doi.org/10.5194/bg-18-4733-2021, 2021
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We have measured the chemical composition of the carbonate shells of the parasitic foraminifera Hyrrokkin sarcophaga in order to test if it is influenced by the host organism (bivalve or coral). We find that both the chemical and isotopic composition is influenced by the host organism. For example strontium is enriched in foraminifera that grew on corals, whose skeleton is built from aragonite, which is naturally enriched in strontium compared to the bivalves' calcite shell.
André Bahr, Monika Doubrawa, Jürgen Titschack, Gregor Austermann, Andreas Koutsodendris, Dirk Nürnberg, Ana Luiza Albuquerque, Oliver Friedrich, and Jacek Raddatz
Biogeosciences, 17, 5883–5908, https://doi.org/10.5194/bg-17-5883-2020, https://doi.org/10.5194/bg-17-5883-2020, 2020
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We explore the sensitivity of cold-water corals (CWCs) to environmental changes utilizing a multiproxy approach on a coral-bearing sediment core from off southeastern Brazil. Our results reveal that over the past 160 kyr, CWCs flourished during glacial high-northern-latitude cold events (Heinrich stadials). These periods were associated with anomalous wet phases on the continent enhancing terrigenous nutrient and organic-matter supply to the continental margin, boosting food supply to the CWCs.
Margot J. Cramwinckel, Lineke Woelders, Emiel P. Huurdeman, Francien Peterse, Stephen J. Gallagher, Jörg Pross, Catherine E. Burgess, Gert-Jan Reichart, Appy Sluijs, and Peter K. Bijl
Clim. Past, 16, 1667–1689, https://doi.org/10.5194/cp-16-1667-2020, https://doi.org/10.5194/cp-16-1667-2020, 2020
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Phases of past transient warming can be used as a test bed to study the environmental response to climate change independent of tectonic change. Using fossil plankton and organic molecules, here we reconstruct surface ocean temperature and circulation in and around the Tasman Gateway during a warming phase 40 million years ago termed the Middle Eocene Climatic Optimum. We find that plankton assemblages track ocean circulation patterns, with superimposed variability being related to temperature.
Georg Schwamborn, Kai Hartmann, Bernd Wünnemann, Wolfgang Rösler, Annette Wefer-Roehl, Jörg Pross, Marlen Schlöffel, Franziska Kobe, Pavel E. Tarasov, Melissa A. Berke, and Bernhard Diekmann
Solid Earth, 11, 1375–1398, https://doi.org/10.5194/se-11-1375-2020, https://doi.org/10.5194/se-11-1375-2020, 2020
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We use a sediment core from the Gobi Desert (Ejina Basin, NW China) to illustrate the landscape history of the area. During 2.5 million years a sediment package of 223 m thickness has been accumulated. Various sediment types document that the area turned from a playa environment (shallow water environment with multiple flooding events) to an alluvial–fluvial environment after the arrival of the Heihe in the area. The river has been diverted due to tectonics.
Bernd R. Schöne, Aliona E. Meret, Sven M. Baier, Jens Fiebig, Jan Esper, Jeffrey McDonnell, and Laurent Pfister
Hydrol. Earth Syst. Sci., 24, 673–696, https://doi.org/10.5194/hess-24-673-2020, https://doi.org/10.5194/hess-24-673-2020, 2020
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We present the first annually resolved stable isotope record (1819–1998) from shells of Swedish river mussels. Data reflect hydrological processes in the catchment and changes in the isotope value of local precipitation. The latter is related to the origin of moisture from which precipitation formed (North Atlantic or the Arctic) and governed by large-scale atmospheric circulation patterns. Results help to better understand climate dynamics and constrain ecological changes in river ecosystems.
Simon Michael Ritter, Margot Isenbeck-Schröter, Christian Scholz, Frank Keppler, Johannes Gescher, Lukas Klose, Nils Schorndorf, Jerónimo Avilés Olguín, Arturo González-González, and Wolfgang Stinnesbeck
Biogeosciences, 16, 2285–2305, https://doi.org/10.5194/bg-16-2285-2019, https://doi.org/10.5194/bg-16-2285-2019, 2019
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Unique and spectacular under water speleothems termed as Hells Bells were recently reported from sinkholes (cenotes) of the Yucatán Peninsula, Mexico. However, the mystery of their formation remained unresolved. Here, we present detailed geochemical analyses and delineate that the growth of Hells Bells results from a combination of biogeochemical processes and variable hydraulic conditions within the cenote.
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.
Joost Frieling, Emiel P. Huurdeman, Charlotte C. M. Rem, Timme H. Donders, Jörg Pross, Steven M. Bohaty, Guy R. Holdgate, Stephen J. Gallagher, Brian McGowran, and Peter K. Bijl
J. Micropalaeontol., 37, 317–339, https://doi.org/10.5194/jm-37-317-2018, https://doi.org/10.5194/jm-37-317-2018, 2018
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The hothouse climate of the early Paleogene and the associated violent carbon cycle perturbations are of particular interest to understanding current and future global climate change. Using dinoflagellate cysts and stable carbon isotope analyses, we identify several significant events, e.g., the Paleocene–Eocene Thermal Maximum in sedimentary deposits from the Otway Basin, SE Australia. We anticipate that this study will facilitate detailed climate reconstructions west of the Tasmanian Gateway.
Peter K. Bijl, Alexander J. P. Houben, Anja Bruls, Jörg Pross, and Francesca Sangiorgi
J. Micropalaeontol., 37, 105–138, https://doi.org/10.5194/jm-37-105-2018, https://doi.org/10.5194/jm-37-105-2018, 2018
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In order to use ocean sediments as a recorder of past oceanographic changes, a critical first step is to stratigraphically date the sediments. The absence of microfossils with known stratigraphic ranges has always hindered dating of Southern Ocean sediments. Here we tie dinocyst ranges to the international timescale in a well-dated sediment core from offshore Antarctica. With this, we can now use dinocysts as a biostratigraphic tool in otherwise stratigraphically poorly dated sediments.
Stephanie L. Strother, Ulrich Salzmann, Francesca Sangiorgi, Peter K. Bijl, Jörg Pross, Carlota Escutia, Ariadna Salabarnada, Matthew J. Pound, Jochen Voss, and John Woodward
Biogeosciences, 14, 2089–2100, https://doi.org/10.5194/bg-14-2089-2017, https://doi.org/10.5194/bg-14-2089-2017, 2017
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One of the main challenges in Antarctic vegetation reconstructions is the uncertainty in unambiguously identifying reworked pollen and spore assemblages in marine sedimentary records influenced by waxing and waning ice sheets. This study uses red fluorescence and digital imaging as a new tool to identify reworking in a marine sediment core from circum-Antarctic waters to reconstruct Cenozoic climate change and vegetation with high confidence.
Odile Peyron, Nathalie Combourieu-Nebout, David Brayshaw, Simon Goring, Valérie Andrieu-Ponel, Stéphanie Desprat, Will Fletcher, Belinda Gambin, Chryssanthi Ioakim, Sébastien Joannin, Ulrich Kotthoff, Katerina Kouli, Vincent Montade, Jörg Pross, Laura Sadori, and Michel Magny
Clim. Past, 13, 249–265, https://doi.org/10.5194/cp-13-249-2017, https://doi.org/10.5194/cp-13-249-2017, 2017
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This study aims to reconstruct the climate evolution of the Mediterranean region during the Holocene from pollen data and model outputs. The model- and pollen-inferred precipitation estimates show overall agreement: the eastern Medit. experienced wetter-than-present summer conditions during the early–late Holocene. This regional climate model highlights how the patchy nature of climate signals and data in the Medit. may lead to stronger local signals than the large-scale pattern suggests.
Oliver Friedrich, Sietske J. Batenburg, Kazuyoshi Moriya, Silke Voigt, Cécile Cournède, Iris Möbius, Peter Blum, André Bornemann, Jens Fiebig, Takashi Hasegawa, Pincelli M. Hull, Richard D. Norris, Ursula Röhl, Thomas Westerhold, Paul A. Wilson, and IODP Expedition
Clim. Past Discuss., https://doi.org/10.5194/cp-2016-51, https://doi.org/10.5194/cp-2016-51, 2016
Manuscript not accepted for further review
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A lack of knowledge on the timing of Late Cretaceous climatic change inhibits our understanding of underlying causal mechanisms. Therefore, we used an expanded deep ocean record from the North Atlantic that shows distinct sedimentary cyclicity suggesting orbital forcing. A high-resolution carbon-isotope record from bulk carbonates allows to identify global trends in the carbon cycle. Our new carbon isotope record and the established cyclostratigraphy may serve as a future reference site.
O. Friedrich, R. D. Norris, P. A. Wilson, and B. N. Opdyke
Sci. Dril., 19, 39–42, https://doi.org/10.5194/sd-19-39-2015, https://doi.org/10.5194/sd-19-39-2015, 2015
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This workshop brought together specialists from various fields to develop a drilling proposal to fill the “Oligo-Miocene Gap” that exists in our understanding of the functions of Earth’s systems. We propose to establish the first continuous high-deposition record of the Oligo-Miocene through International Ocean Discovery Program (IODP) drilling in the North Atlantic. We give a short overview of the major topics discussed during the workshop and the scientific goals of the resulting pre-proposal.
E. O. Walliser, B. R. Schöne, T. Tütken, J. Zirkel, K. I. Grimm, and J. Pross
Clim. Past, 11, 653–668, https://doi.org/10.5194/cp-11-653-2015, https://doi.org/10.5194/cp-11-653-2015, 2015
N. A. G. M. van Helmond, A. Sluijs, J. S. Sinninghe Damsté, G.-J. Reichart, S. Voigt, J. Erbacher, J. Pross, and H. Brinkhuis
Clim. Past, 11, 495–508, https://doi.org/10.5194/cp-11-495-2015, https://doi.org/10.5194/cp-11-495-2015, 2015
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Based on the chemistry and microfossils preserved in sediments deposited in a shallow sea, in the current Lower Saxony region (NW Germany), we conclude that changes in Earth’s orbit around the Sun led to enhanced rainfall and organic matter production. The additional supply of organic matter, depleting oxygen upon degradation, and freshwater, inhibiting the mixing of oxygen-rich surface waters with deeper waters, caused the development of oxygen-poor waters about 94 million years ago.
L. Contreras, J. Pross, P. K. Bijl, R. B. O'Hara, J. I. Raine, A. Sluijs, and H. Brinkhuis
Clim. Past, 10, 1401–1420, https://doi.org/10.5194/cp-10-1401-2014, https://doi.org/10.5194/cp-10-1401-2014, 2014
Related subject area
Subject: Ocean Dynamics | Archive: Marine Archives | Timescale: Pleistocene
Sea-level and monsoonal control on the Maldives carbonate platform (Indian Ocean) over the last 1.3 million years
Changes in the Red Sea Overturning Circulation during Marine Isotope Stage 3
Bottom water oxygenation changes in the southwestern Indian Ocean as an indicator for enhanced respired carbon storage since the last glacial inception
An Intertropical Convergence Zone shift controlled the terrestrial material supply on the Ninetyeast Ridge
Sea ice changes in the southwest Pacific sector of the Southern Ocean during the last 140 000 years
Summer sea-ice variability on the Antarctic margin during the last glacial period reconstructed from snow petrel (Pagodroma nivea) stomach-oil deposits
Variations in export production, lithogenic sediment transport and iron fertilization in the Pacific sector of the Drake Passage over the past 400 kyr
Lower oceanic δ13C during the last interglacial period compared to the Holocene
Change in the North Atlantic circulation associated with the mid-Pleistocene transition
A multi-proxy analysis of Late Quaternary ocean and climate variability for the Maldives, Inner Sea
Central Arctic Ocean paleoceanography from ∼ 50 ka to present, on the basis of ostracode faunal assemblages from the SWERUS 2014 expedition
Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins
Mediterranean Outflow Water variability during the Early Pleistocene
Last Glacial Maximum and deglacial abyssal seawater oxygen isotopic ratios
Subsurface North Atlantic warming as a trigger of rapid cooling events: evidence from the early Pleistocene (MIS 31–19)
Photic zone changes in the north-west Pacific Ocean from MIS 4–5e
Seasonal changes in glacial polynya activity inferred from Weddell Sea varves
High-latitude obliquity as a dominant forcing in the Agulhas current system
Sensitivity of Red Sea circulation to sea level and insolation forcing during the last interglacial
Sea-surface salinity variations in the northern Caribbean Sea across the Mid-Pleistocene Transition
Oceanic tracer and proxy time scales revisited
Variations in mid-latitude North Atlantic surface water properties during the mid-Brunhes (MIS 9–14) and their implications for the thermohaline circulation
A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic δ13C gradient
High Arabian Sea productivity conditions during MIS 13 – odd monsoon event or intensified overturning circulation at the end of the Mid-Pleistocene transition?
Montserrat Alonso-Garcia, Jesus Reolid, Francisco J. Jimenez-Espejo, Or M. Bialik, Carlos A. Alvarez Zarikian, Juan C. Laya, Igor Carrasquiera, Luigi Jovane, John J. G. Reijmer, Christian Betzler, and Gregor P. Eberli
Clim. Past Discuss., https://doi.org/10.5194/cp-2023-68, https://doi.org/10.5194/cp-2023-68, 2023
Revised manuscript accepted for CP
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This article presents a record of carbonate production in the Maldives atolls (Indian Ocean) by coral reefs and other calcareous organisms. During the last 1.3 Million years the carbonate production was controlled by sea-level variations but also by the oceanographic and atmospheric conditions linked to the Indian monsoon. A clear shift towards a more successful carbonate production is observed at about 900.000 years and about 430.000 years, probably setting up the modern reef environments.
Raphaël Hubert-Huard, Nils Andersen, Helge W. Arz, Werner Ehrmann, and Gerhard Schmiedl
EGUsphere, https://doi.org/10.5194/egusphere-2023-1677, https://doi.org/10.5194/egusphere-2023-1677, 2023
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We have studied the geochemistry of benthic foraminifera (micro-fossils) from a sediment core from the Red Sea. Our data show that the circulation and carbon cycling of the Red Sea during the last glacial period responded to high-latitude millennial-scale climate variability and to the orbital influence of the African-Indian monsoon system. This implies a sensitive response of the Red Sea to climate changes.
Helen Eri Amsler, Lena Mareike Thöle, Ingrid Stimac, Walter Geibert, Minoru Ikehara, Gerhard Kuhn, Oliver Esper, and Samuel Laurent Jaccard
Clim. Past, 18, 1797–1813, https://doi.org/10.5194/cp-18-1797-2022, https://doi.org/10.5194/cp-18-1797-2022, 2022
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We present sedimentary redox-sensitive trace metal records from five sediment cores retrieved from the SW Indian Ocean. These records are indicative of oxygen-depleted conditions during cold periods and enhanced oxygenation during interstadials. Our results thus suggest that deep-ocean oxygenation changes were mainly controlled by ocean ventilation and that a generally more sluggish circulation contributed to sequestering remineralized carbon away from the atmosphere during glacial periods.
Xudong Xu, Jianguo Liu, Yun Huang, Lanlan Zhang, Liang Yi, Shengfa Liu, Yiping Yang, Li Cao, and Long Tan
Clim. Past, 18, 1369–1384, https://doi.org/10.5194/cp-18-1369-2022, https://doi.org/10.5194/cp-18-1369-2022, 2022
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Terrestrial materials in marine environments record source information and help us understand how climate and ocean impact sediment compositions. Here, we use evidence on the Ninetyeast Ridge to analyze the relationship between terrestrial material supplementation and climatic change. We find that the ITCZ controlled the rainfall in the Burman source area and that closer connections occurred between the Northern–Southern Hemisphere in the eastern Indian Ocean during the late LGM.
Jacob Jones, Karen E. Kohfeld, Helen Bostock, Xavier Crosta, Melanie Liston, Gavin Dunbar, Zanna Chase, Amy Leventer, Harris Anderson, and Geraldine Jacobsen
Clim. Past, 18, 465–483, https://doi.org/10.5194/cp-18-465-2022, https://doi.org/10.5194/cp-18-465-2022, 2022
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We provide new winter sea ice and summer sea surface temperature estimates for marine core TAN1302-96 (59° S, 157° E) in the Southern Ocean. We find that sea ice was not consolidated over the core site until ~65 ka and therefore believe that sea ice may not have been a major contributor to early glacial CO2 drawdown. Sea ice does appear to have coincided with Antarctic Intermediate Water production and subduction, suggesting it may have influenced intermediate ocean circulation changes.
Erin L. McClymont, Michael J. Bentley, Dominic A. Hodgson, Charlotte L. Spencer-Jones, Thomas Wardley, Martin D. West, Ian W. Croudace, Sonja Berg, Darren R. Gröcke, Gerhard Kuhn, Stewart S. R. Jamieson, Louise Sime, and Richard A. Phillips
Clim. Past, 18, 381–403, https://doi.org/10.5194/cp-18-381-2022, https://doi.org/10.5194/cp-18-381-2022, 2022
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Sea ice is important for our climate system and for the unique ecosystems it supports. We present a novel way to understand past Antarctic sea-ice ecosystems: using the regurgitated stomach contents of snow petrels, which nest above the ice sheet but feed in the sea ice. During a time when sea ice was more extensive than today (24 000–30 000 years ago), we show that snow petrel diet had varying contributions of fish and krill, which we interpret to show changing sea-ice distribution.
María H. Toyos, Gisela Winckler, Helge W. Arz, Lester Lembke-Jene, Carina B. Lange, Gerhard Kuhn, and Frank Lamy
Clim. Past, 18, 147–166, https://doi.org/10.5194/cp-18-147-2022, https://doi.org/10.5194/cp-18-147-2022, 2022
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Past export production in the southeast Pacific and its link to Patagonian ice dynamics is unknown. We reconstruct biological productivity changes at the Pacific entrance to the Drake Passage, covering the past 400 000 years. We show that glacial–interglacial variability in export production responds to glaciogenic Fe supply from Patagonia and silica availability due to shifts in oceanic fronts, whereas dust, as a source of lithogenic material, plays a minor role.
Shannon A. Bengtson, Laurie C. Menviel, Katrin J. Meissner, Lise Missiaen, Carlye D. Peterson, Lorraine E. Lisiecki, and Fortunat Joos
Clim. Past, 17, 507–528, https://doi.org/10.5194/cp-17-507-2021, https://doi.org/10.5194/cp-17-507-2021, 2021
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The last interglacial was a warm period that may provide insights into future climates. Here, we compile and analyse stable carbon isotope data from the ocean during the last interglacial and compare it to the Holocene. The data show that Atlantic Ocean circulation was similar during the last interglacial and the Holocene. We also establish a difference in the mean oceanic carbon isotopic ratio between these periods, which was most likely caused by burial and weathering carbon fluxes.
Gloria M. Martin-Garcia, Francisco J. Sierro, José A. Flores, and Fátima Abrantes
Clim. Past, 14, 1639–1651, https://doi.org/10.5194/cp-14-1639-2018, https://doi.org/10.5194/cp-14-1639-2018, 2018
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This work documents major oceanographic changes that occurred in the N. Atlantic from 812 to 530 ka and were related to the mid-Pleistocene transition. Since ~ 650 ka, glacials were more prolonged and intense than before. Larger ice sheets may have worked as a positive feedback mechanism to prolong the duration of glacials. We explore the connection between the change in the N. Atlantic oceanography and the enhanced ice-sheet growth, which contributed to the change of cyclicity in climate.
Dorothea Bunzel, Gerhard Schmiedl, Sebastian Lindhorst, Andreas Mackensen, Jesús Reolid, Sarah Romahn, and Christian Betzler
Clim. Past, 13, 1791–1813, https://doi.org/10.5194/cp-13-1791-2017, https://doi.org/10.5194/cp-13-1791-2017, 2017
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We investigated a sediment core from the Maldives to unravel the interaction between equatorial climate and ocean variability of the past 200 000 years. The sedimentological, geochemical and foraminiferal data records reveal enhanced dust, which was transported by intensified winter monsoon winds during glacial conditions. Precessional fluctuations of bottom water oxygen suggests an expansion of the Arabian Sea OMZ and a varying inflow of Antarctic Intermediate Water.
Laura Gemery, Thomas M. Cronin, Robert K. Poirier, Christof Pearce, Natalia Barrientos, Matt O'Regan, Carina Johansson, Andrey Koshurnikov, and Martin Jakobsson
Clim. Past, 13, 1473–1489, https://doi.org/10.5194/cp-13-1473-2017, https://doi.org/10.5194/cp-13-1473-2017, 2017
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Continuous, highly abundant and well-preserved fossil ostracodes were studied from radiocarbon-dated sediment cores collected on the Lomonosov Ridge (Arctic Ocean) that indicate varying oceanographic conditions during the last ~50 kyr. Ostracode assemblages from cores taken during the SWERUS-C3 2014 Expedition, Leg 2, reflect paleoenvironmental changes during glacial, deglacial, and interglacial transitions, including changes in sea-ice cover and Atlantic Water inflow into the Eurasian Basin.
Thomas M. Cronin, Matt O'Regan, Christof Pearce, Laura Gemery, Michael Toomey, Igor Semiletov, and Martin Jakobsson
Clim. Past, 13, 1097–1110, https://doi.org/10.5194/cp-13-1097-2017, https://doi.org/10.5194/cp-13-1097-2017, 2017
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Global sea level rise during the last deglacial flooded the Siberian continental shelf in the Arctic Ocean. Sediment cores, radiocarbon dating, and microfossils show that the regional sea level in the Arctic rose rapidly from about 12 500 to 10 700 years ago. Regional sea level history on the Siberian shelf differs from the global deglacial sea level rise perhaps due to regional vertical adjustment resulting from the growth and decay of ice sheets.
Stefanie Kaboth, Patrick Grunert, and Lucas Lourens
Clim. Past, 13, 1023–1035, https://doi.org/10.5194/cp-13-1023-2017, https://doi.org/10.5194/cp-13-1023-2017, 2017
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This study is devoted to reconstructing Mediterranean Outflow Water (MOW) variability and the interplay between the Mediterranean and North Atlantic climate systems during the Early Pleistocene. We find indication that the increasing production of MOW aligns with the intensification of the North Atlantic overturning circulation, highlighting the potential of MOW to modulate the North Atlantic salt budget. Our results are based on new stable isotope and grain-size data from IODP 339 Site U1389.
Carl Wunsch
Clim. Past, 12, 1281–1296, https://doi.org/10.5194/cp-12-1281-2016, https://doi.org/10.5194/cp-12-1281-2016, 2016
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This paper examines the oxygen isotope data in several deep-sea cores. The question addressed is whether those data support an inference that the abyssal ocean in the Last Glacial Maximum period was significantly colder than it is today. Along with a separate analysis of salinity data in the same cores, it is concluded that a cold, saline deep ocean is consistent with the available data but so is an abyss much more like that found today. LGM model testers should beware.
I. Hernández-Almeida, F.-J. Sierro, I. Cacho, and J.-A. Flores
Clim. Past, 11, 687–696, https://doi.org/10.5194/cp-11-687-2015, https://doi.org/10.5194/cp-11-687-2015, 2015
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This manuscript presents new Mg/Ca and previously published δ18O measurements of Neogloboquadrina pachyderma sinistral for MIS 31-19, from a sediment core from the subpolar North Atlantic. The mechanism proposed here involves northward subsurface transport of warm and salty subtropical waters during periods of weaker AMOC, leading to ice-sheet instability and IRD discharge. This is the first time that these rapid climate oscillations are described for the early Pleistocene.
G. E. A. Swann and A. M. Snelling
Clim. Past, 11, 15–25, https://doi.org/10.5194/cp-11-15-2015, https://doi.org/10.5194/cp-11-15-2015, 2015
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New diatom isotope records are presented alongside existing geochemical and isotope records to document changes in the photic zone, including nutrient supply and the efficiency of the soft-tissue biological pump, between MIS 4 and MIS 5e in the subarctic north-west Pacific Ocean. The results provide evidence for temporal changes in the strength and efficiency of the regional soft-tissue biological pump, altering the ratio of regenerated to preformed nutrients in the water.
D. Sprenk, M. E. Weber, G. Kuhn, V. Wennrich, T. Hartmann, and K. Seelos
Clim. Past, 10, 1239–1251, https://doi.org/10.5194/cp-10-1239-2014, https://doi.org/10.5194/cp-10-1239-2014, 2014
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Clim. Past, 7, 1285–1296, https://doi.org/10.5194/cp-7-1285-2011, https://doi.org/10.5194/cp-7-1285-2011, 2011
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Short summary
Eastern equatorial Pacific (EEP) thermocline dynamics during the intensification of Northern Hemisphere glaciation (iNHG; ~ 2.5 Ma) currently remain unclear. In light of this uncertainty, we generated geochemical, faunal and sedimentological data for EEP Site 849 (~ 2.75–2.4 Ma). We recorded a thermocline depth change shortly before the final phase of the iNHG, which supports the hypothesis that tropical thermocline shoaling may have contributed to substantial Northern Hemisphere ice growth.
Eastern equatorial Pacific (EEP) thermocline dynamics during the intensification of Northern...
