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| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Dataset Open Access |
| Language: | en |
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PANGAEA
2017
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| Subjects: | |
| Online Access: | https://doi.org/10.1594/PANGAEA.882551 |
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| _version_ | 1867169515054301184 |
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| author | Chalk, Thomas B Hain, Mathis P Foster, Gavin L Rohling, Eelco J Sexton, Philip F Badger, Marcus P S Cherry, Soraya G Hasenfratz, Adam P Haug, Gerald H Jaccard, Samuel H Martínez-García, Alfredo Pälike, Heiko Pancost, Richard D Wilson, Paul A |
| author_facet | Chalk, Thomas B Hain, Mathis P Foster, Gavin L Rohling, Eelco J Sexton, Philip F Badger, Marcus P S Cherry, Soraya G Hasenfratz, Adam P Haug, Gerald H Jaccard, Samuel H Martínez-García, Alfredo Pälike, Heiko Pancost, Richard D Wilson, Paul A |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | During the Mid-Pleistocene Transition (MPT; 1,200-800 kya), Earth's orbitally paced ice age cycles intensified, lengthened from ~40,000 (~40 ky) to ~100 ky, and became distinctly asymmetrical. Testing hypotheses that implicate changing atmospheric CO2 levels as a driver of the MPT has proven difficult with available observations. Here, we use orbitally resolved, boron isotope CO2 data to show that the glacial to interglacial CO2 difference increased from ~43 to ~75 µatm across the MPT, mainly because of lower glacial CO2 levels. Through carbon cycle modeling, we attribute this decline primarily to the initiation of substantive dust-borne iron fertilization of the Southern Ocean during peak glacial stages. We also observe a twofold steepening of the relationship between sea level and CO2-related climate forcing that is suggestive of a change in the dynamics that govern ice sheet stability, such as that expected from the removal of subglacial regolith or interhemispheric ice sheet phase-locking. We argue that neither ice sheet dynamics nor CO2 change in isolation can explain the MPT. Instead, we infer that the MPT was initiated by a change in ice sheet dynamics and that longer and deeper post-MPT ice ages were sustained by carbon cycle feedbacks related to dust fertilization of the Southern Ocean as a consequence of larger ice sheets. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_882551 |
| institution | PANGAEA |
| language | en |
| publishDate | 2017 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Mid-Pleistocene Transition d11B based carbon dioxide levels from ODP Site 165-999 Chalk, Thomas B Hain, Mathis P Foster, Gavin L Rohling, Eelco J Sexton, Philip F Badger, Marcus P S Cherry, Soraya G Hasenfratz, Adam P Haug, Gerald H Jaccard, Samuel H Martínez-García, Alfredo Pälike, Heiko Pancost, Richard D Wilson, Paul A During the Mid-Pleistocene Transition (MPT; 1,200-800 kya), Earth's orbitally paced ice age cycles intensified, lengthened from ~40,000 (~40 ky) to ~100 ky, and became distinctly asymmetrical. Testing hypotheses that implicate changing atmospheric CO2 levels as a driver of the MPT has proven difficult with available observations. Here, we use orbitally resolved, boron isotope CO2 data to show that the glacial to interglacial CO2 difference increased from ~43 to ~75 µatm across the MPT, mainly because of lower glacial CO2 levels. Through carbon cycle modeling, we attribute this decline primarily to the initiation of substantive dust-borne iron fertilization of the Southern Ocean during peak glacial stages. We also observe a twofold steepening of the relationship between sea level and CO2-related climate forcing that is suggestive of a change in the dynamics that govern ice sheet stability, such as that expected from the removal of subglacial regolith or interhemispheric ice sheet phase-locking. We argue that neither ice sheet dynamics nor CO2 change in isolation can explain the MPT. Instead, we infer that the MPT was initiated by a change in ice sheet dynamics and that longer and deeper post-MPT ice ages were sustained by carbon cycle feedbacks related to dust fertilization of the Southern Ocean as a consequence of larger ice sheets. |
| title | Mid-Pleistocene Transition d11B based carbon dioxide levels from ODP Site 165-999 |
| topic | |
| url | https://doi.org/10.1594/PANGAEA.882551 |