Causes of ice age intensification across the Mid-Pleistocene Transition.

التفاصيل البيبلوغرافية
العنوان:	Causes of ice age intensification across the Mid-Pleistocene Transition.
المؤلفون:	Chalk TB; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom; T.chalk@noc.soton.ac.uk M.P.Hain@soton.ac.uk.; Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA 02543., Hain MP; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom; T.chalk@noc.soton.ac.uk M.P.Hain@soton.ac.uk., Foster GL; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom., Rohling EJ; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom.; Research School of Earth Sciences, The Australian National University, Canberra 2601, Australia., Sexton PF; School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes MK7 6AA, United Kingdom., Badger MPS; School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes MK7 6AA, United Kingdom.; Organic Geochemistry Unit, School of Chemistry, The Cabot Institute, University of Bristol, Bristol BS8 1TS, United Kingdom., Cherry SG; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom., Hasenfratz AP; Geologisches Institut, Eidgenössische Technische Hochschule Zürich, 8092 Zürich, Switzerland., Haug GH; Max Planck Institut für Chemie, 55128 Mainz, Germany., Jaccard SL; Institute of Geological Sciences, University of Bern, 3012 Bern, Switzerland.; Oeschger Center for Climate Change Research, University of Bern, 3012 Bern, Switzerland., Martínez-García A; Max Planck Institut für Chemie, 55128 Mainz, Germany., Pälike H; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom.; Center for Marine Environmental Sciences (MARUM), University of Bremen, 28359 Bremen, Germany., Pancost RD; Organic Geochemistry Unit, School of Chemistry, The Cabot Institute, University of Bristol, Bristol BS8 1TS, United Kingdom., Wilson PA; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Southampton SO14 3ZH, United Kingdom.
المصدر:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2017 Dec 12; Vol. 114 (50), pp. 13114-13119. Date of Electronic Publication: 2017 Nov 27.
نوع المنشور:	Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, Non-U.S. Gov't
اللغة:	English
بيانات الدورية:	Publisher: National Academy of Sciences Country of Publication: United States NLM ID: 7505876 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1091-6490 (Electronic) Linking ISSN: 00278424 NLM ISO Abbreviation: Proc Natl Acad Sci U S A Subsets: PubMed not MEDLINE
أسماء مطبوعة:	Original Publication: Washington, DC : National Academy of Sciences
مستخلص:	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 CO 2 levels as a driver of the MPT has proven difficult with available observations. Here, we use orbitally resolved, boron isotope CO 2 data to show that the glacial to interglacial CO 2 difference increased from ∼43 to ∼75 μatm across the MPT, mainly because of lower glacial CO 2 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 CO 2 -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 CO 2 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. Competing Interests: The authors declare no conflict of interest. (Copyright © 2017 the Author(s). Published by PNAS.)
References:	Nature. 2011 Aug 03;476(7360):312-5. (PMID: 21814203) Proc Natl Acad Sci U S A. 2015 Jun 2;112(22):6887-91. (PMID: 25964367) Science. 2009 Jun 19;324(5934):1551-4. (PMID: 19541994) Science. 2013 Mar 22;339(6126):1419-23. (PMID: 23520109) Nature. 2010 Jul 1;466(7302):47-55. (PMID: 20596012) Nature. 2015 Feb 5;518(7537):49-54. (PMID: 25652996) Science. 2014 Mar 21;343(6177):1347-50. (PMID: 24653031) Nature. 2008 Jan 17;451(7176):284-5. (PMID: 18202644) Nature. 2013 Aug 8;500(7461):190-3. (PMID: 23925242) Nat Commun. 2014 Sep 25;5:5076. (PMID: 25254503) Science. 2007 Apr 6;316(5821):66-9. (PMID: 17412948) Nature. 2016 Oct 13;538(7624):226-228. (PMID: 27669024) Nature. 2014 Apr 24;508(7497):477-82. (PMID: 24739960) Science. 2012 Aug 10;337(6095):704-9. (PMID: 22879512) Nature. 2011 Dec 8;480(7376):229-32. (PMID: 22158246) Science. 2014 Jul 18;345(6194):318-22. (PMID: 24968939)
فهرسة مساهمة:	Keywords: MPT; boron isotopes; carbon dioxide; geochemistry; paleoclimate
تواريخ الأحداث:	Date Created: 20171129 Date Completed: 20180622 Latest Revision: 20181113
رمز التحديث:	20221213
مُعرف محوري في PubMed:	PMC5740680
DOI:	10.1073/pnas.1702143114
PMID:	29180424
قاعدة البيانات:	MEDLINE

الوصف
تدمد:	1091-6490
DOI:	10.1073/pnas.1702143114