Mid-Pleistocene revolution and the "eccentricity myth"

Author(s): Maslin, Mark A.; Ridgwell, Andy J.
Author Affiliation(s): Primary:
University College London, Department of Geography, London, United Kingdom
University of British Columbia, Canada
Volume Title: Early-middle Pleistocene transitions; the land-ocean evidence
Volume Author(s): Head, Martin J., editor; Gibbard, Philip L.
Source: Geological Society Special Publications, Vol.247, p.19-34; Early-middle Pleistocene transitions; the land-ocean evidence, Cambridge, United Kingdom, April 4, 2003, edited by Martin J. Head and Philip L. Gibbard. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719 CODEN: GSLSBW
Note: In English. 64 refs.; illus.
Summary: The mid-Pleistocene revolution (MPR) is the term used to describe the transition between 41 ka and 100 ka glacial-interglacial cycles which occurred about one million years ago. 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-MPR 100 ka climate cycles. The traditional solution to this is to call for a highly nonlinear response by the global climate system to eccentricity. This 'eccentricity myth' is a simplified view of the relationship between global climate and orbital forcing and is in part due to an artefact of spectral analysis. Our aim here is to clarify the often confused role of eccentricity and review current theories of the MPR. We suggest that the post-MPR "100 Ka" glacial-interglacial cycles are more closely linked to precession, with the saw-toothed climate cycles being defined by every four or five precessional cycle. Because control over the number of precessional cycles involved is determined by eccentricity, eccentricity at most paces rather than drives the system. If true, then one must also question whether the MPR, itself defined by an abrupt change in spectral characteristics, is not also somewhat misconceived.
Year of Publication: 2005
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Carbon cycle; Carbon dioxide; Cenozoic; Climate change; Climate forcing; Cores; Cyclic processes; Deglaciation; Eccentricity; Foraminifera; Geochemical cycle; Glacial geology; Glaciation; Global change; Ice; Ice sheets; Insolation; Invertebrata; Isotope ratios; Isotopes; Leg 108; Lower Pleistocene; Marine sediments; Microfossils; Middle Pleistocene; O-18/O-16; ODP Site 659; Obliquity of the ecliptic; Ocean Drilling Program; Orbital forcing; Oxygen; Paleoclimatology; Paleoenvironment; Pleistocene; Precession; Protista; Quaternary; Sediments; Spectra; Stable isotopes; Volume
Coordinates: N180437 N183438 W0210134 W0210135
Record ID: 2006031593
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