Maslin, MA;
Brierley, CM;
(2015)
The role of orbital forcing in the Early Middle Pleistocene Transition.
Quaternary International
, 389
10.1016/j.quaint.2015.01.047.
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Abstract
The Early Middle Pleistocene Transition (EMPT) is the term used to describe the prolongation and intensification of glacial-interglacial climate cycles that initiated after 900,000 years ago. During the transition glacial-interglacial cycles shift from lasting 41,000 years to an average of 100,000 years. The structure of these glacial-interglacial cycles shifts from smooth to more abrupt 'saw-toothed' like transitions. Despite eccentricity having by far the weakest influence on insolation received at the Earth's surface of any of the orbital parameters; it is often assumed to be the primary driver of the post-EMPT 100,000 years climate cycles because of the similarity in duration. The traditional solution to this is to call for a highly nonlinear response by the global climate system to eccentricity. This 'eccentricity myth' is due to an artefact of spectral analysis which means that the last 8 glacial-interglacial average out at about 100,000 years in length despite ranging from 80,000 to 120,000 years. With the realisation that eccentricity is not the major driving force a debate has emerged as to whether precession or obliquity controlled the timing of the most recent glacial-interglacial cycles. Some argue that post-EMPT deglaciations occurred every four or five precessional cycle while others argue it is every second or third obliquity cycle. We review these current theories and suggest that though phase-locking between orbital forcing and global ice volume may occur the chaotic nature of the climate system response means the relationship is not consistent through the last 900,000 years.
Type: | Article |
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Title: | The role of orbital forcing in the Early Middle Pleistocene Transition |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1016/j.quaint.2015.01.047 |
Publisher version: | http://dx.doi.org/10.1016/j.quaint.2015.01.047 |
Language: | English |
Additional information: | Copyright © 2015. This manuscript version is published under a Creative Commons Attribution Non-commercial Non-derivative 4.0 International licence (CC BY-NC-ND 4.0). This licence allows you to share, copy, distribute and transmit the work for personal and non-commercial use providing author and publisher attribution is clearly stated. Further details about CC BY licences are available at http://creativecommons.org/licenses/by/4.0. |
Keywords: | Orbital forcing; Early Middle Pleistocene Transition; Mid Pleistocene Transition; Precession; Obliquity; Eccentricity |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL SLASH UCL > Provost and Vice Provost Offices > UCL SLASH > Faculty of S&HS UCL > Provost and Vice Provost Offices > UCL SLASH > Faculty of S&HS > Dept of Geography |
URI: | https://discovery.ucl.ac.uk/id/eprint/1465569 |
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