連続脱ガスと地球環境の安定性 : 地球化学的炭素循環モデルからの制約  [in Japanese] Continuous degassing and climate stability during the Earth's history: constraints from a carbon geochemical cycle model  [in Japanese]

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Author(s)

    • 田近 英一 TAJIKA Eiichi
    • 東京大学大学院理学系研究科地質学専攻 Geological Institute, School of Science, University of Tokyo

Abstract

The rate of CO<sub>2</sub> degassing to the atmosphere-ocean system via volcanism has probably changed greatly during the history of the Earth. Change of the CO<sub>2</sub> degassing rate results in change of the atmospheric CO<sub>2</sub> level and so the climate, through the geochemical cycle of carbon at the surface of the Earth. If the CO<sub>2</sub> degassing may cease or weaken suddenly, a carbon geochemical cycle model coupled with ocean chemistry and the climate model predicts that the Earth's surface environment should cool very rapidly on the order of 10<sup>5</sup> yr, and, at last, fall into the globally ice covered state. The time required for this is estimated to be on the order of 10<sup>6</sup> years throughout the Earth's history, irrespective of large change of the atmospheric CO<sub>2</sub> level with time. However, absence of geological evidence for such an exstreme climate in the past suggests that the CO<sub>2</sub> degassing process via volcanism should have been almost contiuous, at least, on the order of >10<sup>5</sup>-10<sup>6</sup> yr, which indicates continuity of plate tectonics on the Earth.

Journal

  • Chikyukagaku

    Chikyukagaku 33(4), 255-263, 1999

    The Geochemical Society of Japan

References:  28

Codes

  • NII Article ID (NAID)
    110008679989
  • NII NACSIS-CAT ID (NCID)
    AN00141280
  • Text Lang
    JPN
  • Article Type
    REV
  • ISSN
    0386-4073
  • NDL Article ID
    4917760
  • NDL Source Classification
    ZM41(科学技術--地球科学)
  • NDL Call No.
    Z15-645
  • Data Source
    CJP  NDL  NII-ELS  J-STAGE 
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