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dc.contributor.author
Chalk, Thomas B.
dc.contributor.author
Hain, Mathis P.
dc.contributor.author
Foster, Gavin L.
dc.contributor.author
Rohling, Eelco J.
dc.contributor.author
Sexton, Philip F.
dc.contributor.author
Badger, Marcus P.S.
dc.contributor.author
Cherry, Soraya G.
dc.contributor.author
Hasenfratz, Adam P.
dc.contributor.author
Haug, Gerald H.
dc.contributor.author
Jaccard, Samuel L.
dc.contributor.author
Martínez-García, Alfredo
dc.contributor.author
Pälike, Heiko
dc.contributor.author
Pancost, Richard D.
dc.contributor.author
Wilson, Paul A.
dc.date.accessioned
2018-01-24T17:06:41Z
dc.date.available
2018-01-24T17:06:41Z
dc.date.available
2018-01-24T17:06:14Z
dc.date.available
2018-01-23T09:04:37Z
dc.date.available
2017-12-28T03:37:26Z
dc.date.available
2018-01-17T16:07:42Z
dc.date.issued
2017-12-12
dc.identifier.issn
0027-8424
dc.identifier.issn
1091-6490
dc.identifier.other
10.1073/pnas.1702143114
en_US
dc.identifier.uri
http://hdl.handle.net/20.500.11850/235044
dc.identifier.doi
10.3929/ethz-b-000224668
dc.description.abstract
During the Mid-Pleistocene Transition (MPT; 1,200-800 kya), Earth's orbitally paced ice age cycles intensified, lengthened from similar to 40,000 (similar to 40 ky) to similar 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 similar to 43 to similar to 75 mu atm 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.
en_US
dc.language.iso
en
en_US
dc.publisher
National Academy of Sciences
en_US
dc.rights.uri
http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject
boron isotopes
en_US
dc.subject
MPT
en_US
dc.subject
geochemistry
en_US
dc.subject
carbon dioxide
en_US
dc.subject
paleoclimate
en_US
dc.title
Causes of ice age intensification across the Mid-Pleistocene Transition
en_US
dc.type
Journal Article
dc.rights.license
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
dc.date.published
2017-11-27
ethz.journal.title
Proceedings of the National Academy of Sciences of the United States of America
ethz.journal.volume
114
en_US
ethz.journal.issue
50
en_US
ethz.journal.abbreviated
PNAS
ethz.pages.start
13114
en_US
ethz.pages.end
13119
en_US
ethz.version.deposit
publishedVersion
en_US
ethz.identifier.wos
ethz.identifier.scopus
ethz.publication.place
Washington, DC
en_US
ethz.publication.status
published
en_US
ethz.leitzahl
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02330 - Dep. Erdwissenschaften / Dep. of Earth Sciences::03775 - Haug, Gerald H. / Haug, Gerald H.
en_US
ethz.leitzahl.certified
ETH Zürich::00002 - ETH Zürich::00012 - Lehre und Forschung::00007 - Departemente::02330 - Dep. Erdwissenschaften / Dep. of Earth Sciences::03775 - Haug, Gerald H. / Haug, Gerald H.
en_US
ethz.tag
MIDDLE PLEISTOCENE TRANSITION; DEEP-WATER CIRCULATION; LAST GLACIAL MAXIMUM; BORON ISOTOPE; ATMOSPHERIC CO2; SEA-LEVEL; FORAMINIFERAL CALCITE; CLIMATE TRANSITION; CARBON-DIOXIDE; CARIBBEAN SEA
en_US
ethz.date.deposited
2017-12-28T03:37:35Z
ethz.source
SCOPUS
ethz.eth
yes
en_US
ethz.availability
Open access
en_US
ethz.rosetta.installDate
2018-01-26T09:17:41Z
ethz.rosetta.lastUpdated
2018-11-06T07:29:41Z
ethz.rosetta.exportRequired
true
ethz.rosetta.versionExported
true
dc.identifier.olduri
http://hdl.handle.net/20.500.11850/232787
dc.identifier.olduri
http://hdl.handle.net/20.500.11850/224668
ethz.COinS
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