Climate response to orbital forcing across the Oligocene-Miocene boundary


Zachos, J.C., Shackleton, N.J., Revenaugh, J.S., Pälike, H. and Flower, B.P. (2001) Climate response to orbital forcing across the Oligocene-Miocene boundary. Science, 292, (5515), 274-278. (doi:10.1126/science.1058288).

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Original Publication URL: http://dx.doi.org/10.1126/science.1058288

Description/Abstract

Spectral analyses of an uninterrupted 5.5-million-year (My)-long chronology of late Oligocene-early Miocene climate and ocean carbon chemistry from two deep-sea cores recovered in the western equatorial Atlantic reveal variance concentrated at all Milankovitch frequencies. Exceptional spectral power in climate is recorded at the 406-thousand-year (ky) period eccentricity band over a 3.4-million-year period [20 to 23.4 My ago (Ma)] as well as in the 125- and 95-ky bands over a 1.3-million-year period (21.7 to 23.0 Ma) of suspected low greenhouse gas levels. Moreover, a major transient glaciation at the epoch boundary (~23 Ma), Mi-1, corresponds with a rare orbital congruence involving obliquity and eccentricity. The anomaly, which consists of low-amplitude variance in obliquity (a node) and a minimum in eccentricity, results in an extended period (~200 ky) of low seasonality orbits favorable to ice-sheet expansion on Antarctic.

Item Type: Article
ISSNs: 0036-8075 (print)
Related URLs:
Subjects: Q Science > QE Geology
Divisions: University Structure - Pre August 2011 > School of Ocean & Earth Science (SOC/SOES)
ePrint ID: 13488
Date Deposited: 07 Dec 2004
Last Modified: 27 Mar 2014 18:03
URI: http://eprints.soton.ac.uk/id/eprint/13488

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