GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 116, No. 45 ( 2019-11-05), p. 22500-22504
    Abstract: Mass extinction at the Cretaceous–Paleogene (K-Pg) boundary coincides with the Chicxulub bolide impact and also falls within the broader time frame of Deccan trap emplacement. Critically, though, empirical evidence as to how either of these factors could have driven observed extinction patterns and carbon cycle perturbations is still lacking. Here, using boron isotopes in foraminifera, we document a geologically rapid surface-ocean pH drop following the Chicxulub impact, supporting impact-induced ocean acidification as a mechanism for ecological collapse in the marine realm. Subsequently, surface water pH rebounded sharply with the extinction of marine calcifiers and the associated imbalance in the global carbon cycle. Our reconstructed water-column pH gradients, combined with Earth system modeling, indicate that a partial ∼50% reduction in global marine primary productivity is sufficient to explain observed marine carbon isotope patterns at the K-Pg, due to the underlying action of the solubility pump. While primary productivity recovered within a few tens of thousands of years, inefficiency in carbon export to the deep sea lasted much longer. This phased recovery scenario reconciles competing hypotheses previously put forward to explain the K-Pg carbon isotope records, and explains both spatially variable patterns of change in marine productivity across the event and a lack of extinction at the deep sea floor. In sum, we provide insights into the drivers of the last mass extinction, the recovery of marine carbon cycling in a postextinction world, and the way in which marine life imprints its isotopic signal onto the geological record.
    Type of Medium: Online Resource
    ISSN: 0027-8424 , 1091-6490
    RVK:
    RVK:
    Language: English
    Publisher: Proceedings of the National Academy of Sciences
    Publication Date: 2019
    detail.hit.zdb_id: 209104-5
    detail.hit.zdb_id: 1461794-8
    SSG: 11
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    Copernicus GmbH ; 2018
    In:  Biogeosciences Vol. 15, No. 12 ( 2018-06-21), p. 3779-3794
    In: Biogeosciences, Copernicus GmbH, Vol. 15, No. 12 ( 2018-06-21), p. 3779-3794
    Abstract: Abstract. In this contribution we explore constraints on the fractions of deep water present in the Indian and Pacific oceans which originated in the northern Atlantic and in the Southern Ocean. Based on PO4* we show that if ventilated Antarctic shelf waters characterize the Southern contribution, then the proportions could be close to 50–50. If instead a Southern Ocean bottom water value is used, the Southern contribution is increased to 75 %. While this larger estimate may best characterize the volume of water entering the Indo-Pacific from the Southern Ocean, it contains a significant portion of entrained northern water. We also note that ventilation may be highly tracer dependent: for instance Southern Ocean waters may contribute only 35 % of the deep radiocarbon budget, even if their volumetric contribution is 75 %. In our estimation, the most promising approaches involve using CFC-11 to constrain the amount of deep water formed in the Southern Ocean. Finally, we highlight the broad utility of PO4* as a tracer of deep water masses, including descending plumes of Antarctic Bottom Water and large-scale patterns of deep ocean mixing, and as a tracer of the efficiency of the biological pump.
    Type of Medium: Online Resource
    ISSN: 1726-4189
    Language: English
    Publisher: Copernicus GmbH
    Publication Date: 2018
    detail.hit.zdb_id: 2158181-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Online Resource
    Online Resource
    The Royal Society ; 2016
    In:  Philosophical Transactions of the Royal Society B: Biological Sciences Vol. 371, No. 1694 ( 2016-05-19), p. 20150510-
    In: Philosophical Transactions of the Royal Society B: Biological Sciences, The Royal Society, Vol. 371, No. 1694 ( 2016-05-19), p. 20150510-
    Abstract: Pelagic ecosystem function is integral to global biogeochemical cycling, and plays a major role in modulating atmospheric CO 2 concentrations ( p CO 2 ). Uncertainty as to the effects of human activities on marine ecosystem function hinders projection of future atmospheric p CO 2 . To this end, events in the geological past can provide informative case studies in the response of ecosystem function to environmental and ecological changes. Around the Cretaceous–Palaeogene (K–Pg) boundary, two such events occurred: Deccan large igneous province (LIP) eruptions and massive bolide impact at the Yucatan Peninsula. Both perturbed the environment, but only the impact coincided with marine mass extinction. As such, we use these events to directly contrast the response of marine biogeochemical cycling to environmental perturbation with and without changes in global species richness. We measure this biogeochemical response using records of deep-sea carbonate preservation. We find that Late Cretaceous Deccan volcanism prompted transient deep-sea carbonate dissolution of a larger magnitude and timescale than predicted by geochemical models. Even so, the effect of volcanism on carbonate preservation was slight compared with bolide impact. Empirical records and geochemical models support a pronounced increase in carbonate saturation state for more than 500 000 years following the mass extinction of pelagic carbonate producers at the K–Pg boundary. These examples highlight the importance of pelagic ecosystems in moderating climate and ocean chemistry.
    Type of Medium: Online Resource
    ISSN: 0962-8436 , 1471-2970
    RVK:
    Language: English
    Publisher: The Royal Society
    Publication Date: 2016
    detail.hit.zdb_id: 1462620-2
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    In: Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 112, No. 52 ( 2015-12-29), p. 15970-15975
    Abstract: Systemic juvenile idiopathic arthritis (sJIA) is an often severe, potentially life-threatening childhood inflammatory disease, the pathophysiology of which is poorly understood. To determine whether genetic variation within the MHC locus on chromosome 6 influences sJIA susceptibility, we performed an association study of 982 children with sJIA and 8,010 healthy control subjects from nine countries. Using meta-analysis of directly observed and imputed SNP genotypes and imputed classic HLA types, we identified the MHC locus as a bona fide susceptibility locus with effects on sJIA risk that transcended geographically defined strata. The strongest sJIA-associated SNP, rs151043342 [ P = 2.8 × 10 −17 , odds ratio (OR) 2.6 (2.1, 3.3)], was part of a cluster of 482 sJIA-associated SNPs that spanned a 400-kb region and included the class II HLA region. Conditional analysis controlling for the effect of rs151043342 found that rs12722051 independently influenced sJIA risk [ P = 1.0 × 10 −5 , OR 0.7 (0.6, 0.8)]. Meta-analysis of imputed classic HLA-type associations in six study populations of Western European ancestry revealed that HLA-DRB1*11 and its defining amino acid residue, glutamate 58, were strongly associated with sJIA [ P = 2.7 × 10 −16 , OR 2.3 (1.9, 2.8)], as was the HLA-DRB1*11—HLA-DQA1*05—HLA-DQB1*03 haplotype [6.4 × 10 −17 , OR 2.3 (1.9, 2.9)]. By examining the MHC locus in the largest collection of sJIA patients assembled to date, this study solidifies the relationship between the class II HLA region and sJIA, implicating adaptive immune molecules in the pathogenesis of sJIA.
    Type of Medium: Online Resource
    ISSN: 0027-8424 , 1091-6490
    RVK:
    RVK:
    Language: English
    Publisher: Proceedings of the National Academy of Sciences
    Publication Date: 2015
    detail.hit.zdb_id: 209104-5
    detail.hit.zdb_id: 1461794-8
    SSG: 11
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: Biological Psychiatry, Elsevier BV, Vol. 77, No. 8 ( 2015-04), p. 740-748
    Type of Medium: Online Resource
    ISSN: 0006-3223
    RVK:
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2015
    detail.hit.zdb_id: 1499907-9
    SSG: 12
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...