Abstract

The Milankovitch theory of orbital forcing fails to explain the 100-kyr pacing of the recent glacial cycles since the eccentricity cycle produces negligible changes in seasonal or mean annual insolation on this timescale. The 100-kyr periodicity has been proposed to arise from eccentricity pacing, obliquity pacing, or internal climate variability. A purely statistical test1, based on cross-wavelet analysis between an untuned benthic isotope record (the LR04 stack) and insolation for the past 1.2 Myr, supports eccentricity pacing. Here, we present a new version of this statistical test, which takes into consideration updated uncertainty estimates for the untuned LR04 age model. The new untuned age model is independent of orbital forcing but assumes a constant sediment rate between age control points, after adjustment for compaction. The age control points are provided by the radiometrically-dated magnetic reversals of the …

Date

2014

Authors

Deborah Khider, Lorraine E Lisiecki

Journal

AGU Fall Meeting Abstracts

Volume

2014

Pages

PP41D-1436