Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective
Relative contributions of ice volume and temperature change to the global ∼1‰ δ18O increase at ∼14 Ma are required for understanding feedbacks involved in this major Cenozoic climate transition. A 3‐ma benthic foraminifer Mg/Ca record of Southern Ocean temperatures across the middle Miocene climate...
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-1576 2023-05-15T13:34:05+02:00 Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective Shevenell, Amelia E. Kennett, James P. Lea, David W. 2008-02-01T08:00:00Z application/pdf https://digitalcommons.usf.edu/msc_facpub/585 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1576&context=msc_facpub unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/585 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1576&context=msc_facpub default Marine Science Faculty Publications paleoceanography Cenozoic climate geochemistry Antarctica Life Sciences article 2008 ftunisfloridatam 2021-10-09T07:50:02Z Relative contributions of ice volume and temperature change to the global ∼1‰ δ18O increase at ∼14 Ma are required for understanding feedbacks involved in this major Cenozoic climate transition. A 3‐ma benthic foraminifer Mg/Ca record of Southern Ocean temperatures across the middle Miocene climate transition reveals ∼2 ± 2°C cooling (14.2–13.8 Ma), indicating that ∼70% of the increase relates to ice growth. Seawater δ18O, calculated from Mg/Ca and δ18O, suggests that at ∼15 Ma Antarctica's cryosphere entered an interval of apparent eccentricity‐paced expansion. Glaciations increased in intensity, revealing a central role for internal climate feedbacks. Comparison of ice volume and ocean temperature records with inferred pCO2 levels indicates that middle Miocene cryosphere expansion commenced during an interval of Southern Ocean warmth and low atmospheric pCO2. The Antarctic system appears sensitive to changes in heat/moisture supply when atmospheric pCO2 was low, suggesting the importance of internal feedbacks in this climate transition. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Southern Ocean Digital Commons University of South Florida (USF) Antarctic Southern Ocean The Antarctic |
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Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
paleoceanography Cenozoic climate geochemistry Antarctica Life Sciences |
spellingShingle |
paleoceanography Cenozoic climate geochemistry Antarctica Life Sciences Shevenell, Amelia E. Kennett, James P. Lea, David W. Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective |
topic_facet |
paleoceanography Cenozoic climate geochemistry Antarctica Life Sciences |
description |
Relative contributions of ice volume and temperature change to the global ∼1‰ δ18O increase at ∼14 Ma are required for understanding feedbacks involved in this major Cenozoic climate transition. A 3‐ma benthic foraminifer Mg/Ca record of Southern Ocean temperatures across the middle Miocene climate transition reveals ∼2 ± 2°C cooling (14.2–13.8 Ma), indicating that ∼70% of the increase relates to ice growth. Seawater δ18O, calculated from Mg/Ca and δ18O, suggests that at ∼15 Ma Antarctica's cryosphere entered an interval of apparent eccentricity‐paced expansion. Glaciations increased in intensity, revealing a central role for internal climate feedbacks. Comparison of ice volume and ocean temperature records with inferred pCO2 levels indicates that middle Miocene cryosphere expansion commenced during an interval of Southern Ocean warmth and low atmospheric pCO2. The Antarctic system appears sensitive to changes in heat/moisture supply when atmospheric pCO2 was low, suggesting the importance of internal feedbacks in this climate transition. |
format |
Article in Journal/Newspaper |
author |
Shevenell, Amelia E. Kennett, James P. Lea, David W. |
author_facet |
Shevenell, Amelia E. Kennett, James P. Lea, David W. |
author_sort |
Shevenell, Amelia E. |
title |
Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective |
title_short |
Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective |
title_full |
Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective |
title_fullStr |
Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective |
title_full_unstemmed |
Middle Miocene Ice sheet Dynamics, Deep‐Sea Temperatures, and Carbon Cycling: A Southern Ocean Perspective |
title_sort |
middle miocene ice sheet dynamics, deep‐sea temperatures, and carbon cycling: a southern ocean perspective |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2008 |
url |
https://digitalcommons.usf.edu/msc_facpub/585 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1576&context=msc_facpub |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/585 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1576&context=msc_facpub |
op_rights |
default |
_version_ |
1766048713991520256 |