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Moretti S, Auderset A, Deutsch C, Schmitz R, Gerber L, Thomas E, Luciani V, Petrizzo MR, Schiebel R, Tripati A, Sexton P, Norris R, D'Onofrio R, Zachos J, Sigman DM, Haug GH, Martínez-García A. Oxygen rise in the tropical upper ocean during the Paleocene-Eocene Thermal Maximum. Science 2024; 383:727-731. [PMID: 38359106 DOI: 10.1126/science.adh4893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 01/14/2024] [Indexed: 02/17/2024]
Abstract
The global ocean's oxygen inventory is declining in response to global warming, but the future of the low-oxygen tropics is uncertain. We report new evidence for tropical oxygenation during the Paleocene-Eocene Thermal Maximum (PETM), a warming event that serves as a geologic analog to anthropogenic warming. Foraminifera-bound nitrogen isotopes indicate that the tropical North Pacific oxygen-deficient zone contracted during the PETM. A concomitant increase in foraminifera size implies that oxygen availability rose in the shallow subsurface throughout the tropical North Pacific. These changes are consistent with ocean model simulations of warming, in which a decline in biological productivity allows tropical subsurface oxygen to rise even as global ocean oxygen declines. The tropical oxygen increase may have helped avoid a mass extinction during the PETM.
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Affiliation(s)
- Simone Moretti
- Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
- Istituto di Scienze Polari, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Alexandra Auderset
- Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
- School of Ocean and Earth Science, University of Southampton, Southampton, UK
| | - Curtis Deutsch
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Ronja Schmitz
- Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
| | - Lukas Gerber
- Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
| | - Ellen Thomas
- Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA
- Department of Earth and Environmental Sciences, Wesleyan University, Middletown, CT, USA
| | - Valeria Luciani
- Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Ferrara, Italy
| | - Maria Rose Petrizzo
- Dipartimento di Scienze della Terra "Ardito Desio," Università Degli Studi di Milano, Milan, Italy
| | - Ralf Schiebel
- Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
| | - Aradhna Tripati
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Institute of the Environment and Sustainability, University of California, Los Angeles, Los Angeles, CA, USA
| | - Philip Sexton
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - Richard Norris
- Scripps Institute of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Roberta D'Onofrio
- Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Ferrara, Italy
- Present address: CNR, Marine Science Institute (ISMAR), Arsenale Castello 2737/f, 30122 Venezia, Italy
| | - James Zachos
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Daniel M Sigman
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Gerald H Haug
- Climate Geochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
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Pogge von Strandmann PAE, Jones MT, West AJ, Murphy MJ, Stokke EW, Tarbuck G, Wilson DJ, Pearce CR, Schmidt DN. Lithium isotope evidence for enhanced weathering and erosion during the Paleocene-Eocene Thermal Maximum. SCIENCE ADVANCES 2021; 7:eabh4224. [PMID: 34652934 PMCID: PMC8519576 DOI: 10.1126/sciadv.abh4224] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
The Paleocene-Eocene Thermal Maximum (PETM; ~55.9 Ma) was a geologically rapid warming period associated with carbon release, which caused a marked increase in the hydrological cycle. Here, we use lithium (Li) isotopes to assess the global change in weathering regime, a critical carbon drawdown mechanism, across the PETM. We find a negative Li isotope excursion of ~3‰ in both global seawater (marine carbonates) and in local weathering inputs (detrital shales). This is consistent with a very large delivery of clays to the oceans or a shift in the weathering regime toward higher physical erosion rates and sediment fluxes. Our seawater records are best explained by increases in global erosion rates of ~2× to 3× over 100 ka, combined with model-derived weathering increases of 50 to 60% compared to prewarming values. Such increases in weathering and erosion would have supported enhanced carbon burial, as both carbonate and organic carbon, thereby stabilizing climate.
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Affiliation(s)
- Philip A. E. Pogge von Strandmann
- Institute of Geosciences, Johannes Gutenberg University, 55122 Mainz, Germany
- London Geochemistry and Isotope Centre (LOGIC), Institute of Earth and Planetary Sciences, University College London and Birkbeck, University of London, Gower Place, London WC1E 6BS, UK
| | - Morgan T. Jones
- Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Pb. 1028 Blindern, 0315 Oslo, Norway
| | - A. Joshua West
- Department of Earth Sciences, University of Southern California, 3651 Trousdale Parkway—ZHS 117, Los Angeles, CA 90089, USA
| | - Melissa J. Murphy
- London Geochemistry and Isotope Centre (LOGIC), Institute of Earth and Planetary Sciences, University College London and Birkbeck, University of London, Gower Place, London WC1E 6BS, UK
- Centre for Permafrost, University of Copenhagen, Copenhagen, Denmark
| | - Ella W. Stokke
- Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Pb. 1028 Blindern, 0315 Oslo, Norway
| | - Gary Tarbuck
- London Geochemistry and Isotope Centre (LOGIC), Institute of Earth and Planetary Sciences, University College London and Birkbeck, University of London, Gower Place, London WC1E 6BS, UK
| | - David J. Wilson
- London Geochemistry and Isotope Centre (LOGIC), Institute of Earth and Planetary Sciences, University College London and Birkbeck, University of London, Gower Place, London WC1E 6BS, UK
| | - Christopher R. Pearce
- National Oceanography Centre Southampton, University of Southampton Waterfront Campus, European Way, Southampton SO14 3ZH, UK
| | - Daniela N. Schmidt
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
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3
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Clarkson MO, Lenton TM, Andersen MB, Bagard ML, Dickson AJ, Vance D. Upper limits on the extent of seafloor anoxia during the PETM from uranium isotopes. Nat Commun 2021; 12:399. [PMID: 33452243 PMCID: PMC7810695 DOI: 10.1038/s41467-020-20486-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/04/2020] [Indexed: 11/20/2022] Open
Abstract
The Paleocene Eocene Thermal Maximum (PETM) represents a major carbon cycle and climate perturbation that was associated with ocean de-oxygenation, in a qualitatively similar manner to the more extensive Mesozoic Oceanic Anoxic Events. Although indicators of ocean de-oxygenation are common for the PETM, and linked to biotic turnover, the global extent and temporal progression of de-oxygenation is poorly constrained. Here we present carbonate associated uranium isotope data for the PETM. A lack of resolvable perturbation to the U-cycle during the event suggests a limited expansion of seafloor anoxia on a global scale. We use this result, in conjunction with a biogeochemical model, to set an upper limit on the extent of global seafloor de-oxygenation. The model suggests that the new U isotope data, whilst also being consistent with plausible carbon emission scenarios and observations of carbon cycle recovery, permit a maximum ~10-fold expansion of anoxia, covering <2% of seafloor area. The expansion of oceanic anoxia during the Paleocene Eocene Thermal Maximum has important implications for faunal turnover patterns and global biogeochemical cycles. Here the authors use uranium isotopes and a biogeochemical model to suggest that the areal expansion of anoxia must have been limited to 10-fold.
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Affiliation(s)
| | - Timothy M Lenton
- Global Systems Institute, University of Exeter, Exeter, EX4 4QE, UK
| | - Morten B Andersen
- School of Earth and Ocean Sciences, University of Cardiff, Cardiff, CF10 3AT, UK
| | - Marie-Laure Bagard
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, MK7 6AA, UK.,Department of Earth Science, University of Cambridge, Cambridge, CB2 3EQ, UK
| | - Alexander J Dickson
- Department of Earth Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Derek Vance
- Department of Earth Sciences, ETHZ, 8092, Zurich, Switzerland
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Systematics and evolution of the parasitoid wasp genera of the tribe Holcobraconini (Hymenoptera: Braconidae: Doryctinae). ORG DIVERS EVOL 2019. [DOI: 10.1007/s13127-019-00407-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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5
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Schaller MF, Fung MK. The extraterrestrial impact evidence at the Palaeocene-Eocene boundary and sequence of environmental change on the continental shelf. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0081. [PMID: 30177564 PMCID: PMC6127391 DOI: 10.1098/rsta.2017.0081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/30/2018] [Indexed: 05/06/2023]
Abstract
We have identified clear evidence of an extraterrestrial impact within the onset of the carbon isotope excursion (CIE) that defines the Palaeocene-Eocene (P-E) boundary hyperthermal event (approx. 56 Ma) from several sites on the eastern Atlantic Coastal Plain and offshore. We review and update the state of the evidence for an impact at the P-E boundary, including a K-Ar cooling age of the ejecta that is indistinguishable from the depositional age at the P-E, which establishes the ejecta horizon as an isochronous stratigraphic indicator at the P-E. Immediately above the ejecta peak at the base of the coastal plain Marlboro Clay unit, we identify a sharp increase in charcoal abundance coincident with the previously observed dramatic increase in magnetic nanoparticles of soil pyrogenic origin. We therefore revisit the observed sequence of events through the P-E boundary on the western Atlantic Coastal Plain, showing that an extraterrestrial impact led to wildfires, landscape denudation and deposition of the thick Marlboro Clay, whose base coincides with the spherule horizon and CIE onset. The Sr/Ca ratio of the spherules indicates that the carbon responsible for the onset may be vaporized CaCO3 target rock mixed with isotopically light carbon from the impactor or elsewhere. Crucially, we do not argue that the impact was responsible for the full manifestation of the CIE observed globally (onset to recovery approx. 170 kyr), rather that a rapid onset was triggered by the impact and followed by additional carbon from other processes such as the eruption of the North Atlantic Igneous Province. Such a scenario agrees well with recent modelling work, though it should be revisited more explicitly.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
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Affiliation(s)
- Morgan F Schaller
- Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Megan K Fung
- Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA
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6
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Turner SK. Constraints on the onset duration of the Paleocene-Eocene Thermal Maximum. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0082. [PMID: 30177565 PMCID: PMC6127381 DOI: 10.1098/rsta.2017.0082] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/25/2018] [Indexed: 05/30/2023]
Abstract
The Paleocene-Eocene Thermal Maximum (PETM, approx. 56 Ma) provides a test case for investigating how the Earth system responds to rapid greenhouse gas-driven warming. However, current rates of carbon emissions are approximately 10 Pg C yr-1, whereas those proposed for the PETM span orders of magnitude-from ≪1 Pg C yr-1 to greater than the anthropogenic rate. Emissions rate estimates for the PETM are hampered by uncertainty over the total mass of PETM carbon released as well as the PETM onset duration. Here, I review constraints on the onset duration of the carbon isotope excursion (CIE) that is characteristic of the event with a focus on carbon cycle model-based attempts that forgo the need for a traditional sedimentary age model. I also review and compare existing PETM carbon input scenarios employing the Earth system model cGENIE and suggest another possibility-that abrupt input of an isotopically depleted carbon source combined with elevated volcanic outgassing over a longer interval can together account for key features of the PETM CIE.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
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7
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Babila TL, Penman DE, Hönisch B, Kelly DC, Bralower TJ, Rosenthal Y, Zachos JC. Capturing the global signature of surface ocean acidification during the Palaeocene-Eocene Thermal Maximum. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0072. [PMID: 30177558 PMCID: PMC6127385 DOI: 10.1098/rsta.2017.0072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Indexed: 05/30/2023]
Abstract
Geologically abrupt carbon perturbations such as the Palaeocene-Eocene Thermal Maximum (PETM, approx. 56 Ma) are the closest geological points of comparison to current anthropogenic carbon emissions. Associated with the rapid carbon release during this event are profound environmental changes in the oceans including warming, deoxygenation and acidification. To evaluate the global extent of surface ocean acidification during the PETM, we present a compilation of new and published surface ocean carbonate chemistry and pH reconstructions from various palaeoceanographic settings. We use boron to calcium ratios (B/Ca) and boron isotopes (δ11B) in surface- and thermocline-dwelling planktonic foraminifera to reconstruct ocean carbonate chemistry and pH. Our records exhibit a B/Ca reduction of 30-40% and a δ11B decline of 1.0-1.2‰ coeval with the carbon isotope excursion. The tight coupling between boron proxies and carbon isotope records is consistent with the interpretation that oceanic absorption of the carbon released at the onset of the PETM resulted in widespread surface ocean acidification. The remarkable similarity among records from different ocean regions suggests that the degree of ocean carbonate change was globally near uniform. We attribute the global extent of surface ocean acidification to elevated atmospheric carbon dioxide levels during the main phase of the PETM.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
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Affiliation(s)
- Tali L Babila
- Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, 71 Dudley Road, New Brunswick, NJ 08901, USA
| | - Donald E Penman
- Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Bärbel Hönisch
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9 W, Palisades, NY 10964, USA
| | - D Clay Kelly
- Department of Geoscience, University of Wisconsin-Madison, 1215 West Dayton Street, Madison, WI 53706, USA
| | - Timothy J Bralower
- Department of Geosciences, Pennsylvania State University, 503 Deike Building, University Park, PA 16802, USA
| | - Yair Rosenthal
- Department of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, 71 Dudley Road, New Brunswick, NJ 08901, USA
- Department of Earth and Planetary Sciences, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, NJ 08854, USA
| | - James C Zachos
- Department of Earth and Planetary Sciences, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
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Grimaldi DA, Sunderlin D, Aaroe GA, Dempsky MR, Parker NE, Tillery GQ, White JG, Barden P, Nascimbene PC, Williams CJ. Biological Inclusions in Amber from the Paleogene Chickaloon Formation of Alaska. AMERICAN MUSEUM NOVITATES 2018. [DOI: 10.1206/3908.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- David A. Grimaldi
- Division of Invertebrate Zoology, American Museum of Natural History, New York
| | - David Sunderlin
- Department of Geology & Environmental Geosciences, Lafayette College, Easton, Pennsylvania
| | - Georgene A. Aaroe
- Department of Geology & Environmental Geosciences, Lafayette College, Easton, Pennsylvania
| | - Michelle R. Dempsky
- Department of Geology & Environmental Geosciences, Lafayette College, Easton, Pennsylvania
| | - Nancy E. Parker
- Department of Geology & Environmental Geosciences, Lafayette College, Easton, Pennsylvania
| | - George Q. Tillery
- Department of Geology & Environmental Geosciences, Lafayette College, Easton, Pennsylvania
| | - Jaclyn G. White
- Department of Geology & Environmental Geosciences, Lafayette College, Easton, Pennsylvania
| | - Phillip Barden
- Department of Biology, New Jersey Institute of Technology, Newark
| | - Paul C. Nascimbene
- Division of Invertebrate Zoology, American Museum of Natural History, New York
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9
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Astronomical age constraints and extinction mechanisms of the Late Triassic Carnian crisis. Sci Rep 2017; 7:2557. [PMID: 28566703 PMCID: PMC5451402 DOI: 10.1038/s41598-017-02817-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/20/2017] [Indexed: 11/26/2022] Open
Abstract
The geological record contains evidence for numerous pronounced perturbations in the global carbon cycle, some of which are associated with mass extinction. In the Carnian (Late Triassic), evidence from sedimentology and fossil pollen points to a significant change in climate, resulting in biotic turnover, during a time termed the ‘Carnian Pluvial Episode’ (CPE). Evidence from the marine realm suggests a causal relationship between the CPE, a global ‘wet’ period, and the injection of light carbon into the atmosphere. Here we provide the first evidence from a terrestrial stratigraphic succession of at least five significant negative C-isotope excursions (CIE)’s through the CPE recorded in both bulk organic carbon and compound specific plant leaf waxes. Furthermore, construction of a floating astronomical timescale for 1.09 Ma of the Late Triassic, based on the recognition of 405 ka eccentricity cycles in elemental abundance and gamma ray (GR) data, allows for the estimation of a duration for the isotope excursion(s). Source mixing calculations reveal that the observed substantial shift(s) in δ13C was most likely caused by a combination of volcanic emissions, subsequent warming and the dissociation of methane clathrates.
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10
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Schaller MF, Fung MK, Wright JD, Katz ME, Kent DV. Impact ejecta at the Paleocene-Eocene boundary. Science 2017; 354:225-229. [PMID: 27738171 DOI: 10.1126/science.aaf5466] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 09/16/2016] [Indexed: 11/02/2022]
Abstract
Extraterrestrial impacts have left a substantial imprint on the climate and evolutionary history of Earth. A rapid carbon cycle perturbation and global warming event about 56 million years ago at the Paleocene-Eocene (P-E) boundary (the Paleocene-Eocene Thermal Maximum) was accompanied by rapid expansions of mammals and terrestrial plants and extinctions of deep-sea benthic organisms. Here, we report the discovery of silicate glass spherules in a discrete stratigraphic layer from three marine P-E boundary sections on the Atlantic margin. Distinct characteristics identify the spherules as microtektites and microkrystites, indicating that an extraterrestrial impact occurred during the carbon isotope excursion at the P-E boundary.
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Affiliation(s)
- Morgan F Schaller
- Earth and Environmental Sciences, Rensselaer Polytechnic Institute (RPI), Troy, NY 12180, USA.
| | - Megan K Fung
- Earth and Environmental Sciences, Rensselaer Polytechnic Institute (RPI), Troy, NY 12180, USA
| | - James D Wright
- Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
| | - Miriam E Katz
- Earth and Environmental Sciences, Rensselaer Polytechnic Institute (RPI), Troy, NY 12180, USA
| | - Dennis V Kent
- Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA. Lamont-Doherty Earth Observatory (LDEO), Columbia University, Palisades, NY 10964, USA
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11
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Frieling J, Gebhardt H, Huber M, Adekeye OA, Akande SO, Reichart GJ, Middelburg JJ, Schouten S, Sluijs A. Extreme warmth and heat-stressed plankton in the tropics during the Paleocene-Eocene Thermal Maximum. SCIENCE ADVANCES 2017; 3:e1600891. [PMID: 28275727 PMCID: PMC5336354 DOI: 10.1126/sciadv.1600891] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 12/27/2016] [Indexed: 05/23/2023]
Abstract
Global ocean temperatures rapidly warmed by ~5°C during the Paleocene-Eocene Thermal Maximum (PETM; ~56 million years ago). Extratropical sea surface temperatures (SSTs) met or exceeded modern subtropical values. With these warm extratropical temperatures, climate models predict tropical SSTs >35°C-near upper physiological temperature limits for many organisms. However, few data are available to test these projected extreme tropical temperatures or their potential lethality. We identify the PETM in a shallow marine sedimentary section deposited in Nigeria. On the basis of planktonic foraminiferal Mg/Ca and oxygen isotope ratios and the molecular proxy [Formula: see text], latest Paleocene equatorial SSTs were ~33°C, and [Formula: see text] indicates that SSTs rose to >36°C during the PETM. This confirms model predictions on the magnitude of polar amplification and refutes the tropical thermostat theory. We attribute a massive drop in dinoflagellate abundance and diversity at peak warmth to thermal stress, showing that the base of tropical food webs is vulnerable to rapid warming.
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Affiliation(s)
- Joost Frieling
- Marine Palynology and Paleoceanography, Laboratory of Palaeobotany and Palynology, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584CS Utrecht, Netherlands
| | - Holger Gebhardt
- Geologische Bundesanstalt, Neulinggasse 38, A 1030 Wien, Austria
| | - Matthew Huber
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47906, USA
| | - Olabisi A. Adekeye
- Department of Geology and Mineral Sciences, University of Ilorin, P.M.B. 1515, Kwara State, Nigeria
| | - Samuel O. Akande
- Department of Geology and Mineral Sciences, University of Ilorin, P.M.B. 1515, Kwara State, Nigeria
| | - Gert-Jan Reichart
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584CS Utrecht, Netherlands
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, ’t Horntje, Texel, Netherlands
| | - Jack J. Middelburg
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584CS Utrecht, Netherlands
| | - Stefan Schouten
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584CS Utrecht, Netherlands
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry, and Utrecht University, ’t Horntje, Texel, Netherlands
| | - Appy Sluijs
- Marine Palynology and Paleoceanography, Laboratory of Palaeobotany and Palynology, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Heidelberglaan 2, 3584CS Utrecht, Netherlands
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12
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Calcareous Nannofossil Assemblage Changes and Paleoecology of the Selandian to Ypresian in Izmit Province, Northwest Turkey. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2017. [DOI: 10.1007/s13369-016-2192-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Mitsui Y, Shimomura M, Komatsu K, Namiki N, Shibata-Hatta M, Imai M, Katayose Y, Mukai Y, Kanamori H, Kurita K, Kagami T, Wakatsuki A, Ohyanagi H, Ikawa H, Minaka N, Nakagawa K, Shiwa Y, Sasaki T. The radish genome and comprehensive gene expression profile of tuberous root formation and development. Sci Rep 2015; 5:10835. [PMID: 26056784 PMCID: PMC4650646 DOI: 10.1038/srep10835] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/08/2015] [Indexed: 12/23/2022] Open
Abstract
Understanding the processes that regulate plant sink formation and development at the molecular level will contribute to the areas of crop breeding, food production and plant evolutionary studies. We report the annotation and analysis of the draft genome sequence of the radish Raphanus sativus var. hortensis (long and thick root radish) and transcriptome analysis during root development. Based on the hybrid assembly approach of next-generation sequencing, a total of 383 Mb (N50 scaffold: 138.17 kb) of sequences of the radish genome was constructed containing 54,357 genes. Syntenic and phylogenetic analyses indicated that divergence between Raphanus and Brassica coincide with the time of whole genome triplication (WGT), suggesting that WGT triggered diversification of Brassiceae crop plants. Further transcriptome analysis showed that the gene functions and pathways related to carbohydrate metabolism were prominently activated in thickening roots, particularly in cell proliferating tissues. Notably, the expression levels of sucrose synthase 1 (SUS1) were correlated with root thickening rates. We also identified the genes involved in pungency synthesis and their transcription factors.
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Affiliation(s)
- Yuki Mitsui
- Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Michihiko Shimomura
- Mitsubishi Space Software Co., Ltd., 1-6-1, Takezono, Tsukuba, Ibaraki 305-0032, Japan
| | - Kenji Komatsu
- Junior College of Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Nobukazu Namiki
- Mitsubishi Space Software Co., Ltd., 1-6-1, Takezono, Tsukuba, Ibaraki 305-0032, Japan
| | - Mari Shibata-Hatta
- Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Misaki Imai
- Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Yuichi Katayose
- National Institute of Agrobiological Sciences, 1-2, Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Yoshiyuki Mukai
- National Institute of Agrobiological Sciences, 1-2, Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Hiroyuki Kanamori
- National Institute of Agrobiological Sciences, 1-2, Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Kanako Kurita
- National Institute of Agrobiological Sciences, 1-2, Owashi, Tsukuba, Ibaraki, 305-8634, Japan
| | - Tsutomu Kagami
- Sakata Seed Corporation, 2-7-1, Nakamachidai, Tuzuki-ku, Yokohama, 224-0041, Japan
| | - Akihito Wakatsuki
- Sakata Seed Corporation, 2-7-1, Nakamachidai, Tuzuki-ku, Yokohama, 224-0041, Japan
| | - Hajime Ohyanagi
- Mitsubishi Space Software Co., Ltd., 1-6-1, Takezono, Tsukuba, Ibaraki 305-0032, Japan
| | - Hiroshi Ikawa
- Mitsubishi Space Software Co., Ltd., 1-6-1, Takezono, Tsukuba, Ibaraki 305-0032, Japan
| | - Nobuhiro Minaka
- 1] Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan [2] National Institute for Agro-Environmental Science, 3-1-3, Tukuba, 305-8604, Japan
| | - Kunihiro Nakagawa
- Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Yu Shiwa
- Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Takuji Sasaki
- 1] Tokyo University of Agriculture, 1-1-1, Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan [2] National Institute of Agrobiological Sciences, 1-2, Owashi, Tsukuba, Ibaraki, 305-8634, Japan
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14
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Rao Q, Leng Y. Methane Aqueous Fluids in Montmorillonite Clay Interlayer under Near-Surface Geological Conditions: A Grand Canonical Monte Carlo and Molecular Dynamics Simulation Study. J Phys Chem B 2014; 118:10956-65. [PMID: 25167085 DOI: 10.1021/jp507884w] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qi Rao
- Department
of Mechanical
and Aerospace Engineering, The George Washington University, Washington, D.C. 20052, United States
| | - Yongsheng Leng
- Department
of Mechanical
and Aerospace Engineering, The George Washington University, Washington, D.C. 20052, United States
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15
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Evidence for a rapid release of carbon at the Paleocene-Eocene thermal maximum. Proc Natl Acad Sci U S A 2013; 110:15908-13. [PMID: 24043840 DOI: 10.1073/pnas.1309188110] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Paleocene/Eocene thermal maximum (PETM) and associated carbon isotope excursion (CIE) are often touted as the best geologic analog for the current anthropogenic rise in pCO2. However, a causal mechanism for the PETM CIE remains unidentified because of large uncertainties in the duration of the CIE's onset. Here, we report on a sequence of rhythmic sedimentary couplets comprising the Paleocene/Eocene Marlboro Clay (Salisbury Embayment). These couplets have corresponding δ(18)O cycles that imply a climatic origin. Seasonal insolation is the only regular climate cycle that can plausibly account for δ(18)O amplitudes and layer counts. High-resolution stable isotope records show 3.5‰ δ(13)C decrease over 13 couplets defining the CIE onset, which requires a large, instantaneous release of (13)C-depleted carbon. During the CIE, a clear δ(13)C gradient developed on the shelf with the largest excursions in shallowest waters, indicating atmospheric δ(13)C decreased by ~20‰. Our observations and revised release rate are consistent with an atmospheric perturbation of 3,000-gigatons of carbon (GtC).
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16
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Wing SL, Currano ED. Plant response to a global greenhouse event 56 million years ago. AMERICAN JOURNAL OF BOTANY 2013; 100:1234-1254. [PMID: 23825133 DOI: 10.3732/ajb.1200554] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PREMISE OF THE STUDY The fossil record provides information about the long-term response of plants to CO2-induced climate change. The Paleocene-Eocene Thermal Maximum (PETM), a 200000-yr-long period of rapid carbon release and warming that occurred ∼56 million years ago, is analogous to future anthropogenic global warming. METHODS We collected plant macrofossils in the Bighorn Basin, Wyoming, United States, from a period spanning the PETM and studied changes in floristic composition. We also compiled and summarized published records of floristic change during the PETM. KEY RESULTS There was radical floristic change in the Bighorn Basin during the PETM reflecting local or regional extirpation of mesophytic plants, notably conifers, and colonization of the area by thermophilic and dry-tolerant species, especially Fabaceae. This floristic change largely reversed itself as the PETM ended, though some immigrant species persisted and some Paleocene species never returned. Less detailed records from other parts of the world show regional variation in floristic response, but are mostly consistent with the Bighorn Basin trends. CONCLUSIONS Despite geologically rapid extirpation, colonization, and recolonization, we detected little extinction during the PETM, suggesting the rate of climate change did not exceed the dispersal capacity of terrestrial plants. Extrapolating the response of plants from the PETM to future anthropogenic climate change likely underestimates risk because rates of climate change during the PETM may have been an order of magnitude slower than current rates of change and because the abundant, widespread species common as fossils are likely resistant to extinction.
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Affiliation(s)
- Scott L Wing
- Department of Paleobiology, P.O. Box 37012, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013 USA.
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17
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Dickens GR. Modeling the Global Carbon Cycle with a Gas Hydrate Capacitor: Significance for the Latest Paleocene Thermal Maximum. NATURAL GAS HYDRATES 2013. [DOI: 10.1029/gm124p0019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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18
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Submarine Slope Failure Primed and Triggered by Bottom Water Warming in Oceanic Hydrate-Bearing Deposits. ENERGIES 2012. [DOI: 10.3390/en5082849] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Honisch B, Ridgwell A, Schmidt DN, Thomas E, Gibbs SJ, Sluijs A, Zeebe R, Kump L, Martindale RC, Greene SE, Kiessling W, Ries J, Zachos JC, Royer DL, Barker S, Marchitto TM, Moyer R, Pelejero C, Ziveri P, Foster GL, Williams B. The Geological Record of Ocean Acidification. Science 2012; 335:1058-63. [DOI: 10.1126/science.1208277] [Citation(s) in RCA: 672] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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20
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High-resolution carbon isotope record for the Paleocene-Eocene thermal maximum from the Nanyang Basin, Central China. CHINESE SCIENCE BULLETIN 2010. [DOI: 10.1007/s11434-010-4092-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Sum AK, Koh CA, Sloan ED. Clathrate Hydrates: From Laboratory Science to Engineering Practice. Ind Eng Chem Res 2009. [DOI: 10.1021/ie900679m] [Citation(s) in RCA: 300] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Amadeu K. Sum
- Center for Hydrate Research, Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401
| | - Carolyn A. Koh
- Center for Hydrate Research, Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401
| | - E. Dendy Sloan
- Center for Hydrate Research, Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401
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22
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Shindell D. Estimating the potential for twenty-first century sudden climate change. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2007; 365:2675-94. [PMID: 17666384 DOI: 10.1098/rsta.2007.2088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
I investigate the potential for sudden climate change during the current century. This investigation takes into account evidence from the Earth's history, from climate models and our understanding of the physical processes governing climate shifts. Sudden alterations to climate forcing seem to be improbable, with sudden changes instead most likely to arise from climate feedbacks. Based on projections from models validated against historical events, dramatic changes in ocean circulation appear unlikely. Ecosystem-climate feedbacks clearly have the potential to induce sudden change, but are relatively poorly understood at present. More probable sudden changes are large increases in the frequency of summer heatwaves and changes resulting from feedbacks involving hydrology. These include ice sheet decay, which may be set in motion this century. The most devastating consequences are likely to occur further in the future, however. Reductions in subtropical precipitation are likely to be the most severe hydrologic effects this century, with rapid changes due to the feedbacks of relatively well-understood large-scale circulation patterns. Water stress may become particularly acute in the Southwest US and Mexico, and in the Mediterranean and Middle East, where rainfall decreases of 10-25% (regionally) and up to 40% (locally) are projected.
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Affiliation(s)
- Drew Shindell
- NASA Goddard Institute for Space Studies, Columbia University, 2880 Broadway, New York, NY 10025, USA.
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23
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24
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Lindow BEK, Dyke GJ. Bird evolution in the Eocene: climate change in Europe and a Danish fossil fauna. Biol Rev Camb Philos Soc 2007. [DOI: 10.1111/j.1469-185x.2006.tb00215.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Surface-water chemistry and fertility variations in the tropical Atlantic across the Paleocene/Eocene Thermal Maximum as evidenced by calcareous nannoplankton from ODP Leg 207, Hole 1259B. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.revmic.2006.10.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Gingerich PD. Environment and evolution through the Paleocene–Eocene thermal maximum. Trends Ecol Evol 2006; 21:246-53. [PMID: 16697910 DOI: 10.1016/j.tree.2006.03.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 01/26/2006] [Accepted: 03/09/2006] [Indexed: 10/24/2022]
Abstract
The modern orders of mammals, Artiodactyla, Perissodactyla and Primates (APP taxa), first appear in the fossil record at the Paleocene-Eocene boundary, c. 55 million years ago. Their appearance on all three northern continents has been linked to diversification and dispersal in response to rapid environmental change at the beginning of a worldwide 100 000-200 000-year Paleocene-Eocene thermal maximum (PETM) and carbon isotope excursion. As I discuss here, global environmental events such as the PETM have had profound effects on evolution in the geological past and must be considered when modeling the history of life. The PETM is also relevant when considering the causes and consequences of global greenhouse warming.
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Affiliation(s)
- Philip D Gingerich
- Museum of Paleontology and Department of Geological Sciences, The University of Michigan, Ann Arbor, MI 48109-1079, USA.
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27
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Ganqing J, Xiaoying S, Shihong Z. Methane seeps, methane hydrate destabilization, and the late Neoproterozoic postglacial cap carbonates. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/s11434-006-1152-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Kemp DB, Coe AL, Cohen AS, Schwark L. Astronomical pacing of methane release in the Early Jurassic period. Nature 2005; 437:396-9. [PMID: 16163353 DOI: 10.1038/nature04037] [Citation(s) in RCA: 335] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Accepted: 07/04/2005] [Indexed: 11/09/2022]
Abstract
A pronounced negative carbon-isotope (delta13C) excursion of approximately 5-7 per thousand (refs 1-7) indicates the occurrence of a significant perturbation to the global carbon cycle during the Early Jurassic period (early Toarcian age, approximately 183 million years ago). The rapid release of 12C-enriched biogenic methane as a result of continental-shelf methane hydrate dissociation has been put forward as a possible explanation for this observation. Here we report high-resolution organic carbon-isotope data from well-preserved mudrocks in Yorkshire, UK, which demonstrate that the carbon-isotope excursion occurred in three abrupt stages, each showing a shift of -2 per thousand to -3 per thousand. Spectral analysis of these carbon-isotope measurements and of high-resolution carbonate abundance data reveals a regular cyclicity. We interpret these results as providing strong evidence that methane release proceeded in three rapid pulses and that these pulses were controlled by astronomically forced changes in climate, superimposed upon longer-term global warming. We also find that the first two pulses of methane release each coincided with the extinction of a large proportion of marine species.
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Affiliation(s)
- David B Kemp
- Department of Earth Sciences, Centre for Earth, Planetary, Space & Astronomical Research, The Open University, Milton Keynes MK7 6AA, UK.
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29
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Gas hydrates: A cleaner source of energy and opportunity for innovative technologies. KOREAN J CHEM ENG 2005. [DOI: 10.1007/bf02705781] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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30
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Zachos JC, Röhl U, Schellenberg SA, Sluijs A, Hodell DA, Kelly DC, Thomas E, Nicolo M, Raffi I, Lourens LJ, McCarren H, Kroon D. Rapid Acidification of the Ocean During the Paleocene-Eocene Thermal Maximum. Science 2005; 308:1611-5. [PMID: 15947184 DOI: 10.1126/science.1109004] [Citation(s) in RCA: 788] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Paleocene-Eocene thermal maximum (PETM) has been attributed to the rapid release of approximately 2000 x 10(9) metric tons of carbon in the form of methane. In theory, oxidation and ocean absorption of this carbon should have lowered deep-sea pH, thereby triggering a rapid (<10,000-year) shoaling of the calcite compensation depth (CCD), followed by gradual recovery. Here we present geochemical data from five new South Atlantic deep-sea sections that constrain the timing and extent of massive sea-floor carbonate dissolution coincident with the PETM. The sections, from between 2.7 and 4.8 kilometers water depth, are marked by a prominent clay layer, the character of which indicates that the CCD shoaled rapidly (<10,000 years) by more than 2 kilometers and recovered gradually (>100,000 years). These findings indicate that a large mass of carbon (>>2000 x 10(9) metric tons of carbon) dissolved in the ocean at the Paleocene-Eocene boundary and that permanent sequestration of this carbon occurred through silicate weathering feedback.
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Affiliation(s)
- James C Zachos
- Earth Sciences Department, Earth and Marine Sciences Building, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
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31
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Jenkyns HC. Evidence for rapid climate change in the Mesozoic-Palaeogene greenhouse world. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2003; 361:1885-916; discussion 1916. [PMID: 14558900 DOI: 10.1098/rsta.2003.1240] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The best-documented example of rapid climate change that characterized the so-called 'greenhouse world' took place at the time of the Palaeocene-Eocene boundary: introduction of isotopically light carbon into the ocean-atmosphere system, accompanied by global warming of 5-8 degrees C across a range of latitudes, took place over a few thousand years. Dissociation, release and oxidation of gas hydrates from continental-margin sites and the consequent rapid global warming from the input of greenhouses gases are generally credited with causing the abrupt negative excursions in carbon- and oxygen-isotope ratios. The isotopic anomalies, as recorded in foraminifera, propagated downwards from the shallowest levels of the ocean, implying that considerable quantities of methane survived upward transit through the water column to oxidize in the atmosphere. In the Mesozoic Era, a number of similar events have been recognized, of which those at the Triassic-Jurassic boundary, in the early Toarcian (Jurassic) and in the early Aptian (Cretaceous) currently carry the best documentation for dramatic rises in temperature. In these three examples, and in other less well-documented cases, the lack of a definitive time-scale for the intervals in question hinders calculation of the rate of environmental change. However, comparison with the Palaeocene-Eocene thermal maximum (PETM) suggests that these older examples could have been similarly rapid. In both the early Toarcian and early Aptian cases, the negative carbon-isotope excursion precedes global excess carbon burial across a range of marine environments, a phenomenon that defines these intervals as oceanic anoxic events (OAEs). Osmium-isotope ratios ((187)Os/(188)Os) for both the early Toarcian OAE and the PETM show an excursion to more radiogenic values, demonstrating an increase in weathering and erosion of continental crust consonant with elevated temperatures. The more highly buffered strontium-isotope system ((87)Sr/(86)Sr) also shows relatively more radiogenic signatures during the early Toarcian OAE, but the early Aptian and Cenomanian-Turonian OAEs show the reverse effect, implying that increased rates of sea-floor spreading and hydrothermal activity dominated over continental weathering in governing sea-water chemistry. The Cretaceous climatic optimum (late Cenomanian to mid Turonian) also shows evidence for abrupt cooling episodes characterized by episodic invasion of boreal faunas into temperate and subtropical regions and changes in terrestrial vegetation; drawdown of CO(2) related to massive marine carbon burial (OAE) may be implicated here. The absence of a pronounced negative carbon-isotope excursion preceding the Cenomanian-Turonian OAE indicates that methane release is not necessarily connected to global deposition of marine organic carbon, but relative thermal maxima are common to all OAEs. 'Cold snaps' have also been identified from the Mesozoic record but their duration, causes and effects are poorly documented.
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Affiliation(s)
- Hugh C Jenkyns
- Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK
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32
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Retallack GJ. Carbon dioxide and climate over the past 300 Myr. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2002; 360:659-673. [PMID: 12804298 DOI: 10.1098/rsta.2001.0960] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The link between atmospheric CO(2) levels and global warming is an axiom of current public policy, and is well supported by physicochemical experiments, by comparative planetary climatology and by geochemical modelling. Geological tests of this idea seek to compare proxies of past atmospheric CO(2) with other proxies of palaeotemperature. For at least the past 300 Myr, there is a remarkably high temporal correlation between peaks of atmospheric CO(2), revealed by study of stomatal indices of fossil leaves of Ginkgo, Lepidopteris, Tatarina and Rhachiphyllum, and palaeotemperature maxima, revealed by oxygen isotopic (delta(18)O) composition of marine biogenic carbonate. Large and growing databases on these proxy indicators support the idea that atmospheric CO(2) and temperature are coupled. In contrast, CO(2)-temperature uncoupling has been proposed from geological time-series of carbon isotopic composition of palaeosols and of marine phytoplankton compared with foraminifera, which fail to indicate high CO(2) at known times of high palaeotemperature. Failure of carbon isotopic palaeobarometers may be due to episodic release of CH(4), which has an unusually light isotopic value (down to -110 per thousand, and typically -60 per thousand delta(13)C) and which oxidizes rapidly (within 7-24 yr) to isotopically light CO(2). Past CO(2) highs (above 2000 ppmv) were not only times of catastrophic release of CH(4) from clathrates, but of asteroid and comet impacts, flood basalt eruptions and mass extinctions. The primary reason for iterative return to low CO(2) was carbon consumption by hydrolytic weathering and photosynthesis, perhaps stimulated by mountain uplift and changing patterns of oceanic thermohaline circulation. Sequestration of carbon was promoted in the long term by such evolutionary innovations as the lignin of forests and the sod of grasslands, which accelerated physicochemical weathering and delivery of nutrients to fuel oceanic productivity and carbon burial.
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33
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Bowen GJ, Clyde WC, Koch PL, Ting S, Alroy J, Tsubamoto T, Wang Y, Wang Y. Mammalian dispersal at the Paleocene/Eocene boundary. Science 2002; 295:2062-5. [PMID: 11896275 DOI: 10.1126/science.1068700] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A profound faunal reorganization occurred near the Paleocene/Eocene boundary, when several groups of mammals abruptly appeared on the Holarctic continents. To test the hypothesis that this event featured the dispersal of groups from Asia to North America and Europe, we used isotope stratigraphy, magnetostratigraphy, and quantitative biochronology to constrain the relative age of important Asian faunas. The extinct family Hyaenodontidae appeared in Asia before it did so in North America, and the modern orders Primates, Artiodactyla, and Perissodactyla first appeared in Asia at or before the Paleocene/Eocene boundary. These results are consistent with Asia being a center for early mammalian origination.
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Affiliation(s)
- Gabriel J Bowen
- Department of Earth Sciences, University of California, Santa Cruz, CA 95064, USA.
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34
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A Geographic Database Approach to the KT Boundary. GEOLOGICAL AND BIOLOGICAL EFFECTS OF IMPACT EVENTS 2002. [DOI: 10.1007/978-3-642-59388-8_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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35
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Traub WA, Jucks KW. A possible aeronomy of extrasolar terrestrial planets. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/130gm25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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36
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Des Marais DJ, Harwit MO, Jucks KW, Kasting JF, Lin DNC, Lunine JI, Schneider J, Seager S, Traub WA, Woolf NJ. Remote sensing of planetary properties and biosignatures on extrasolar terrestrial planets. ASTROBIOLOGY 2002; 2:153-81. [PMID: 12469366 DOI: 10.1089/15311070260192246] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The major goals of NASA's Terrestrial Planet Finder (TPF) and the European Space Agency's Darwin missions are to detect terrestrial-sized extrasolar planets directly and to seek spectroscopic evidence of habitable conditions and life. Here we recommend wavelength ranges and spectral features for these missions. We assess known spectroscopic molecular band features of Earth, Venus, and Mars in the context of putative extrasolar analogs. The preferred wavelength ranges are 7-25 microns in the mid-IR and 0.5 to approximately 1.1 microns in the visible to near-IR. Detection of O2 or its photolytic product O3 merits highest priority. Liquid H2O is not a bioindicator, but it is considered essential to life. Substantial CO2 indicates an atmosphere and oxidation state typical of a terrestrial planet. Abundant CH4 might require a biological source, yet abundant CH4 also can arise from a crust and upper mantle more reduced than that of Earth. The range of characteristics of extrasolar rocky planets might far exceed that of the Solar System. Planetary size and mass are very important indicators of habitability and can be estimated in the mid-IR and potentially also in the visible to near-IR. Additional spectroscopic features merit study, for example, features created by other biosignature compounds in the atmosphere or on the surface and features due to Rayleigh scattering. In summary, we find that both the mid-IR and the visible to near-IR wavelength ranges offer valuable information regarding biosignatures and planetary properties; therefore both merit serious scientific consideration for TPF and Darwin.
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Zachos J, Pagani M, Sloan L, Thomas E, Billups K. Trends, rhythms, and aberrations in global climate 65 Ma to present. Science 2001; 292:686-93. [PMID: 11326091 DOI: 10.1126/science.1059412] [Citation(s) in RCA: 2059] [Impact Index Per Article: 89.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Since 65 million years ago (Ma), Earth's climate has undergone a significant and complex evolution, the finer details of which are now coming to light through investigations of deep-sea sediment cores. This evolution includes gradual trends of warming and cooling driven by tectonic processes on time scales of 10(5) to 10(7) years, rhythmic or periodic cycles driven by orbital processes with 10(4)- to 10(6)-year cyclicity, and rare rapid aberrant shifts and extreme climate transients with durations of 10(3) to 10(5) years. Here, recent progress in defining the evolution of global climate over the Cenozoic Era is reviewed. We focus primarily on the periodic and anomalous components of variability over the early portion of this era, as constrained by the latest generation of deep-sea isotope records. We also consider how this improved perspective has led to the recognition of previously unforeseen mechanisms for altering climate.
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Affiliation(s)
- J Zachos
- Earth Sciences Department, University of California, Santa Cruz, CA 95064, USA.
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38
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Norris RD, Kroon D, Huber BT, Erbacher J. Cretaceous-Palaeogene ocean and climate change in the subtropical North Atlantic. ACTA ACUST UNITED AC 2001. [DOI: 10.1144/gsl.sp.2001.183.01.01] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractOcean Drilling Program (ODP) Leg 171B recovered continuous sequences that yield evidence for a suite of ‘critical’ events in the Earth’s history. The main events include the late Eocene radiolarian extinction, the late Palaeocene benthic foraminiferal extinction associated with the Late Palaeocene Thermal Maximum (LPTM), the Cretaceous-Palaeogene (K-P) extinction, the mid-Maastrichtian event, and several episodes of sapropel deposition documenting the late Cenomanian, late Albian and early Albian warm periods. A compilation of stable isotope results for foraminifera from Leg 171B sites and previously published records shows a series of large-scale cycles in temperature and δ13C trends from Albian to late Eocene time. Evolution of δ18O gradients between planktic and benthic foraminifera suggests that the North Atlantic evolved from a circulation system similar to the modern Mediterranean during early Albian time to a more open ocean circulation by late Albian-early Cenomanian time. Sea surface temperatures peaked during the mid-Cretaceous climatic optimum from the Albian-Cenomanian boundary to Coniacian time and then show a tendency to fall off toward the cool climates of the mid-Maastrichtian. The Albian-Coniacian period is characterized by light benthic oxygen isotope values showing generally warm deep waters. Lightest benthic oxygen isotopes occurred around the Cenomanian-Turonian boundary, and suggest middle bathyal waters with temperatures up to 20 °C in the North Atlantic. The disappearance of widespread sapropel deposition in Turonian time suggests that sills separating the North Atlantic from the rest of the global ocean were finally breached to sufficient depth to permit ventilation by deep waters flowing in from elsewhere. The Maastrichtian and Palaeogene records show two intervals of large-scale carbon burial and exhumation in the late Maastrichtian-Danian and late Palaeocene-early Eocene. Carbon burial peaked in early Danian time, perhaps in response to the withdrawal of large epicontinental seas from Europe and North America. Much of the succeeding Danian period was spent unroofing previously deposited carbon and repairing the damage to carbon export systems in the deep ocean caused by the K-P mass extinction. The youngest episode of carbon exhumation coincided with the onset of the early Eocene Warm Period and the LPTM, and has been attributed to the tectonic closure of the eastern Tethys and initiation of the Himalayan Orogeny.
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Affiliation(s)
- Richard D. Norris
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution
Woods Hole, MA 02543, USA
| | - Dick Kroon
- Department of Geology and Geophysics, University of Edinburgh, Grant Institute
West Mains Road, Edinburgh EH9 3JW, UK
| | - Brian T. Huber
- Department of Palaeobiology, Smithsonian Institution, MRC:NHB 121, National Museum of Natural History
Washington, DC 20560, USA
| | - Jochen Erbacher
- Bundesanstalt für Geowissenschaften und Rohstoffe
Stilleweg 2, 30655 Hannover, Germany
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Bains S, Norris RD, Corfield RM, Faul KL. Termination of global warmth at the Palaeocene/Eocene boundary through productivity feedback. Nature 2000; 407:171-4. [PMID: 11001051 DOI: 10.1038/35025035] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The onset of the Palaeocene/Eocene thermal maximum (about 55 Myr ago) was marked by global surface temperatures warming by 5-7 degrees C over approximately 30,000 yr (ref. 1), probably because of enhanced mantle outgassing and the pulsed release of approximately 1,500 gigatonnes of methane carbon from decomposing gas-hydrate reservoirs. The aftermath of this rapid, intense and global warming event may be the best example in the geological record of the response of the Earth to high atmospheric carbon dioxide concentrations and high temperatures. This response has been suggested to include an intensified flux of organic carbon from the ocean surface to the deep ocean and its subsequent burial through biogeochemical feedback mechanisms. Here we present firm evidence for this view from two ocean drilling cores, which record the largest accumulation rates of biogenic barium--indicative of export palaeoproductivity--at times of maximum global temperatures and peak excursion values of delta13C. The unusually rapid return of delta13C to values similar to those before the methane release and the apparent coupling of the accumulation rates of biogenic barium to temperature, suggests that the enhanced deposition of organic matter to the deep sea may have efficiently cooled this greenhouse climate by the rapid removal of excess carbon dioxide from the atmosphere.
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Affiliation(s)
- S Bains
- Department of Earth Sciences, University of Oxford, UK.
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Carbon cycling and chronology of climate warming during the Palaeocene/Eocene transition. Nature 1999. [DOI: 10.1038/44545] [Citation(s) in RCA: 257] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Affiliation(s)
- Sharon A. Cowling
- The author is in the Climate Impacts Group, Institute of Ecology, Lund University, S-223 62 Lund, Sweden
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