Astronomical pacing of methane release in the Early Jurassic period

Kemp, D. B. and Coe, A.L. and Cohen, A.S. and Schwark, L. (2005) Astronomical pacing of methane release in the Early Jurassic period. Nature, 438 (7068). p. 696. DOI 10.1038/nature04037

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Abstract

A pronounced negative carbon-isotope (delta13C) excursion of approx5–7permil (refs 1–7) indicates the occurrence of a significant perturbation to the global carbon cycle during the Early Jurassic period (early Toarcian age, approx183 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 -2permil to -3permil. 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.

Item Type: Article
Additional Information: Erratum: Astronomical pacing of methane release in the Early Jurassic period David B. Kemp, Angela L. Coe, Anthony S. Cohen and Lorenz Schwark Nature 437, 396–399 (2005) In the labelling of Fig. 1 of this Letter, the spelling of 'D. semicelatum' was accidentally reversed to read 'D. mutalecimes'. It appears correctly in the text. There is a Brief Communications Arising (1 June 2006) associated with this document.doi:10.1038/nature04905
Subjects: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Divisions: 01 - Climate Change and Earth-Ocean Atmosphere Systems
Journal or Publication Title: Nature
Volume: 438
Page Range: p. 696
Identification Number: 10.1038/nature04037
Depositing User: Sarah Humbert
Date Deposited: 23 Jan 2010 01:01
Last Modified: 23 Jul 2013 09:56
URI: http://eprints.esc.cam.ac.uk/id/eprint/1304

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