Obliquity Pacing of the Late Pleistocene Glacial Terminations
Published Version
https://doi.org/10.1038/nature03401Metadata
Show full item recordCitation
Huybers, Peter J., and Carl Wunsch. 2005. Obliquity pacing of the late Pleistocene glacial terminations. Nature 434: 491-494.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.Other Sources
http://www.people.fas.harvard.edu/~phuybers/Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:3382978
Collections
- FAS Scholarly Articles [18304]
Contact administrator regarding this item (to report mistakes or request changes)