Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles
Abstract Supercontinent assembly and breakup can influence the rate and global extent to which insulated and relatively warm subcontinental mantle is mixed globally, potentially introducing lateral oceanic‐continental mantle temperature variations that regulate volcanic and weathering controls on Ea...
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| Format: | Article |
| Language: | English |
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Wiley
2020-02-01
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| Series: | Geochemistry, Geophysics, Geosystems |
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| Online Access: | https://doi.org/10.1029/2019GC008464 |
| _version_ | 1797638099108364288 |
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| author | A. M. Jellinek A. Lenardic R. T. Pierrehumbert |
| author_facet | A. M. Jellinek A. Lenardic R. T. Pierrehumbert |
| author_sort | A. M. Jellinek |
| collection | DOAJ |
| description | Abstract Supercontinent assembly and breakup can influence the rate and global extent to which insulated and relatively warm subcontinental mantle is mixed globally, potentially introducing lateral oceanic‐continental mantle temperature variations that regulate volcanic and weathering controls on Earth's long‐term carbon cycle for a few hundred million years. We propose that the relatively warm and unchanging climate of the Nuna supercontinental epoch (1.8–1.3 Ga) is characteristic of thorough mantle thermal mixing. By contrast, the extreme cooling‐warming climate variability of the Neoproterozoic Rodinia episode (1–0.63 Ga) and the more modest but similar climate change during the Mesozoic Pangea cycle (0.3–0.05 Ga) are characteristic features of the effects of subcontinental mantle thermal isolation with differing longevity. A tectonically modulated carbon cycle model coupled to a one‐dimensional energy balance climate model predicts the qualitative form of Mesozoic climate evolution expressed in tropical sea‐surface temperature and ice sheet proxy data. Applied to the Neoproterozoic, this supercontinental control can drive Earth into, as well as out of, a continuous or intermittently panglacial climate, consistent with aspects of proxy data for the Cryogenian‐Ediacaran period. The timing and magnitude of this cooling‐warming climate variability depends, however, on the detailed character of mantle thermal mixing, which is incompletely constrained. We show also that the predominant modes of chemical weathering and a tectonically paced abiotic methane production at mid‐ocean ridges can modulate the intensity of this climate change. For the Nuna epoch, the model predicts a relatively warm and ice‐free climate related to mantle dynamics potentially consistent with the intense anorogenic magmatism of this period. |
| first_indexed | 2024-03-11T12:58:45Z |
| format | Article |
| id | doaj.art-a1199a6a56b94157a81ede4f7e4d65a0 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:58:45Z |
| publishDate | 2020-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-a1199a6a56b94157a81ede4f7e4d65a02023-11-03T16:55:47ZengWileyGeochemistry, Geophysics, Geosystems1525-20272020-02-01212n/an/a10.1029/2019GC008464Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental CyclesA. M. Jellinek0A. Lenardic1R. T. Pierrehumbert2Department of Earth, Ocean, and Atmospheric Sciences University of British Columbia Vancouver British Columbia CanadaDepartment of Earth Science Rice University Houston TX USADepartment of Atmospheric Physics Clarendon Laboratory, Oxford University Oxford UKAbstract Supercontinent assembly and breakup can influence the rate and global extent to which insulated and relatively warm subcontinental mantle is mixed globally, potentially introducing lateral oceanic‐continental mantle temperature variations that regulate volcanic and weathering controls on Earth's long‐term carbon cycle for a few hundred million years. We propose that the relatively warm and unchanging climate of the Nuna supercontinental epoch (1.8–1.3 Ga) is characteristic of thorough mantle thermal mixing. By contrast, the extreme cooling‐warming climate variability of the Neoproterozoic Rodinia episode (1–0.63 Ga) and the more modest but similar climate change during the Mesozoic Pangea cycle (0.3–0.05 Ga) are characteristic features of the effects of subcontinental mantle thermal isolation with differing longevity. A tectonically modulated carbon cycle model coupled to a one‐dimensional energy balance climate model predicts the qualitative form of Mesozoic climate evolution expressed in tropical sea‐surface temperature and ice sheet proxy data. Applied to the Neoproterozoic, this supercontinental control can drive Earth into, as well as out of, a continuous or intermittently panglacial climate, consistent with aspects of proxy data for the Cryogenian‐Ediacaran period. The timing and magnitude of this cooling‐warming climate variability depends, however, on the detailed character of mantle thermal mixing, which is incompletely constrained. We show also that the predominant modes of chemical weathering and a tectonically paced abiotic methane production at mid‐ocean ridges can modulate the intensity of this climate change. For the Nuna epoch, the model predicts a relatively warm and ice‐free climate related to mantle dynamics potentially consistent with the intense anorogenic magmatism of this period.https://doi.org/10.1029/2019GC008464supercontinental assembly and breakupmantle convective thermal mixinglong‐term climate variabilityNeoproterozoic snowball EarthMesozoic cooling‐warmingPrecambrian global warming |
| spellingShingle | A. M. Jellinek A. Lenardic R. T. Pierrehumbert Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles Geochemistry, Geophysics, Geosystems supercontinental assembly and breakup mantle convective thermal mixing long‐term climate variability Neoproterozoic snowball Earth Mesozoic cooling‐warming Precambrian global warming |
| title | Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles |
| title_full | Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles |
| title_fullStr | Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles |
| title_full_unstemmed | Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles |
| title_short | Ice, Fire, or Fizzle: The Climate Footprint of Earth's Supercontinental Cycles |
| title_sort | ice fire or fizzle the climate footprint of earth s supercontinental cycles |
| topic | supercontinental assembly and breakup mantle convective thermal mixing long‐term climate variability Neoproterozoic snowball Earth Mesozoic cooling‐warming Precambrian global warming |
| url | https://doi.org/10.1029/2019GC008464 |
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