Obliquity Pacing of the Late Pleistocene Glacial Terminations

Obliquity Pacing of the Late Pleistocene Glacial Terminations

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Obliquity Pacing of the Late Pleistocene Glacial Terminations

dc.contributor.author	Huybers, Peter John
dc.contributor.author	Wunsch, Carl
dc.date.accessioned	2009-11-05T18:26:07Z
dc.date.issued	2005
dc.identifier.citation	Huybers, Peter J., and Carl Wunsch. 2005. Obliquity pacing of the late Pleistocene glacial terminations. Nature 434: 491-494.	en_US
dc.identifier.issn	0028-0836	en_US
dc.identifier.uri	http://nrs.harvard.edu/urn-3:HUL.InstRepos:3382978
dc.description.abstract	The 100,000-year timescale in the glacial/interglacial cycles of the late Pleistocene epoch (the past ,700,000 years) is commonly attributed to control by variations in the Earth’s orbit. This hypothesis has inspired models that depend on the Earth’s obliquity (,40,000 yr; ,40 kyr), orbital eccentricity (,100 kyr) and precessional (,20 kyr) fluctuations, with the emphasis usually on eccentricity and precessional forcing. According to a contrasting hypothesis, the glacial cycles arise primarily because of random internal climate variability. Taking these two perspectives together, there are currently more than thirty different models of the seven late-Pleistocene glacial cycles. Here we present a statistical test of the orbital forcing hypothesis, focusing on the rapid deglaciation events known as terminations. According to our analysis, the null hypothesis that glacial terminations are independent of obliquity can be rejected at the 5% significance level, whereas the corresponding null hypotheses for eccentricity and precession cannot be rejected. The simplest inference consistent with the test results is that the ice sheets terminated every second or third obliquity cycle at times of high obliquity, similar to the original proposal by Milankovitch. We also present simple stochastic and deterministic models that describe the timing of the late-Pleistocene glacial terminations purely in terms of obliquity forcing.	en_US
dc.description.sponsorship	Earth and Planetary Sciences	en_US
dc.language.iso	en_US	en_US
dc.publisher	Nature Publishing Group	en_US
dc.relation.isversionof	http://dx.doi.org/10.1038/nature03401	en_US
dc.relation.hasversion	http://www.people.fas.harvard.edu/~phuybers/	en_US
dash.license	LAA
dc.title	Obliquity Pacing of the Late Pleistocene Glacial Terminations	en_US
dc.type	Journal Article	en_US
dc.description.version	Version of Record	en_US
dc.relation.journal	Nature -London-	en_US
dash.depositing.author	Huybers, Peter John
dc.date.available	2009-11-05T18:26:07Z