Re-examination of the cause of the Paleocene-Eocene thermal maximum, based on global carbon-cycle modeling

• Yasukawa Kazutaka

  Department of Systems Innovation, School of Engineering, The University of Tokyo

• Nakamura Kentaro

  Japan Agency for Marine-Earth Science and Technology

• Kato Yasuhiro

  Department of Systems Innovation, School of Engineering, The University of Tokyo

Bibliographic Information

Other Title

• 地球表層炭素循環モデリングに基づく暁新世／始新世境界温暖化極大の発生原因の再検討
• チキュウ ヒョウソウ タンソ ジュンカン モデリング ニ モトズク ギョウシンセイ シシンセイ キョウカイ オンダンカ キョクダイ ノ ハッセイ ゲンイン ノ サイケントウ

Abstract

One of the most dramatic global warming events in the Earth’s history occurred at the Paleocene-Eocene boundary (ca. 55 Ma). During the Paleocene-Eocene thermal maximum (PETM), the global temperature increased by more than 4°C within a few thousand years, accompanied by an abrupt negative carbon isotope excursion (CIE) in both the marine and terrestrial environments. Although this excursion implies a massive and rapid addition of ¹³C-depleted carbon to the oceans and atmosphere, the source of the massive carbon injection during the PETM remains uncertain.<br>To provide some constraints on the cause of the PETM, we re-examined the observed magnitude of the CIE, and then reconstructed the perturbation of the global carbon cycle during the PETM, using a simple one-box global carbon-cycle model.<br>The eruption of the North Atlantic Igneous Province (NAIP) appears to be the most plausible candidate for a triggering mechanism of the PETM. Our model indicates that the CIE of –3‰ is best explained by inputs of 2,200 Gt-C of thermogenic methane, produced by NAIP volcanism, and 700–2,800 Gt-C of biogenic methane produced by the subsequent dissociation of seafloor gas hydrates within 10 kyr. The uncertainty in the mass of released biogenic methane is attributed mainly to high variability in atmospheric pCO₂ reconstructed for the late Paleocene (ranging from <300 to >2,000 ppm). However, the global temperature rise calculated by our model is 1.4°C at most, and we cannot reconstruct a temperature anomaly exceeding 4°C.

Journal

• The Journal of the Geological Society of Japan

  The Journal of the Geological Society of Japan 116 (8), 418-436, 2010

  The Geological Society of Japan

Keywords

• Paleocene-Eocene thermal maximum (PETM)
• carbon isotope excursion
• global warming
• methane hydrate
• thermogenic methane
• global carbon-cycle modeling

Details

• CRID: 1390001206238051584
• NII Article ID: 130000413567
• NII Book ID: AN00141768
• DOI: 10.5575/geosoc.116.418
• COI: 1:CAS:528:DC%2BC3cXhsVCqtrbN
• ISSN: 13499963
• ISSN: 00167630
• NDL BIB ID: 10814285
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I10814285
• Web Site: https://www.jstage.jst.go.jp/article/geosoc/116/8/116_8_418/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed