Plio-Pleistocene Ice Volume, Antarctic Climate, and the Global δ 18 O Record

We propose that from ∼3 to 1 million years ago, ice volume changes occurred in both the Northern and Southern Hemispheres, each controlled by local summer insolation. Because Earth's orbital precession is out of phase between hemispheres, 23,000-year changes in ice volume in each hemisphere can...

Full description

Bibliographic Details
Published in:Science
Main Authors: Raymo, M. E., Lisiecki, L. E., Nisancioglu, Kerim H.
Format: Article in Journal/Newspaper
Language:English
Published: American Association for the Advancement of Science (AAAS) 2006
Subjects:
Antarctic
East Antarctica
Antarc*
Antarctica
Ice Sheet
Online Access:http://dx.doi.org/10.1126/science.1123296
https://www.science.org/doi/pdf/10.1126/science.1123296
Description
Summary:We propose that from ∼3 to 1 million years ago, ice volume changes occurred in both the Northern and Southern Hemispheres, each controlled by local summer insolation. Because Earth's orbital precession is out of phase between hemispheres, 23,000-year changes in ice volume in each hemisphere cancel out in globally integrated proxies such as ocean δ 18 O or sea level, leaving the in-phase obliquity (41,000 years) component of insolation to dominate those records. Only a modest ice mass change in Antarctica is required to effectively cancel out a much larger northern ice volume signal. At the mid-Pleistocene transition, we propose that marine-based ice sheet margins replaced terrestrial ice margins around the perimeter of East Antarctica, resulting in a shift to in-phase behavior of northern and southern ice sheets as well as the strengthening of 23,000-year cyclicity in the marine δ 18 O record.

Similar Items